The descriptions in this work are founded on original observations of material and a consideration of the literature. The sources of this material are various museums which house collections of Iraqi species including in particular the Natural History Museum, London (formerly the British Museum (Natural History), BM(NH)), the Naturhistorisches Museum Wien (NMW), and the Field Museum, Chicago (FMNH). The former two are depositories for older type material. Extensive comparative material is available from Iran (in the Canadian Museum of Nature, CMNFI) and Syria (in the Senckenberg Museum, Frankfurt, SMF). Some Iraqi material is stored at the Canadian Museum of Nature, Ottawa which also has an extensive literature base including translations from foreign languages, and comparative specimens and literature from other countries in Southwest Asia. Material is listed by acronym and catalogue number, number of specimens (unless there is a single specimen), length, locality, date and collector. Many institutions are now on-line and collection information is often in an abbreviated form as more details can be found at the institution's website.
It should be noted that the number and disposition of older types in particular can change over time as they are researched in more detail and are more fully understood. Not all counts of numbers of specimens and their catalogue numbers from literature are in accord with fish in jars.
There are various methods of measuring and counting anatomical features of fishes. The ones used here are outlined in Freshwater Fishes of Iran at www.briancoad.com. They are based on Hubbs and Lagler (1958) and Trautman (1981). Some particular characters are outlined in papers by Coad in the Bibliography.
The method of counting fin rays differs from that in use in North America since unbranched and branched rays are counted separately. A "III,8" count in the European literature would be "9" in the system advocated by Hubbs and Lagler (1958), i.e. the soft ray count is increased by one to convert from the "European" to the "American" system. The bulk of the work on fishes of southwest Asia follows the European system and this methodology is adopted here to facilitate comparisons. Roman numerals are eschewed as they are not always instantly familiar to readers in the Middle East.
A) Meristic characters
In this work, scale counts, number of gill rakers and of vertebrae are usually expressed as ranges based on literature sources since frequency counts are rarely given. Fin ray counts often show strong modes, but citing the mode alone would be misleading. Pharyngeal tooth formula is often a modal value from the literature; loss of or incomplete development of major or minor row teeth is not uncommon, so counts may vary quite markedly.
Scale counts and paired fin ray counts were made on the left side of each fish. In some instances, such as a badly deformed fin or where scales on the left were mostly missing, counts were made on the right. These instances were rare and restricted to species with low sample sizes.
Not all meristic characters had equal sample sizes; some material from other museums was not available for x-rays, large series of pharyngeal tooth counts was not often available because removal of arches damages specimens, some specimens were damaged in certain characters, time did not always permit all characters to be counted, some species are well-known and additional data from Iraq is clearly a subset of widely gathered data, some species were examined in detail to address systematic problems, and so on.
1) Vertebrae
All vertebrae were counted including the hypural plate as one vertebra. In Cypriniformes and Siluriformes, the four Weberian vertebrae were included in the count. Almost all counts were made from radiographs.
2) Gill rakers
All rakers on the first gill arch were counted. A lower limb count in the literature includes any raker at the angle of the upper and lower limbs. Gill raker counts presented something of a problem when comparing specimens of disparate sizes. The smaller fish often had very small rakers at each end of the arch. These were easily missed or torn off when cleaning a debris-encrusted arch. Removal of arches for a more careful examination may also damage or destroy the finer rakers which are intimately associated with the tissues adjacent to the arches. Alizarin preparations can be of assistance, but the finer rakers may have no bony content and thereby be omitted. Counts of juvenile fish may therefore give lower values than counts for larger fish, whether this be due to an increase in gill raker number with age (Salman et al., 1993) or because rakers are more easy to count in larger fish. This kind of variation is only critical where this character is being used in species identification or in analyses meant to define and relate species.
3) Pharyngeal teeth
The teeth of the modified fifth gill arch in Cyprinidae were counted in each row and given as a formula from left to right. A count of 2,5-4,2 consists of two teeth in both the outer left and outer right rows, five teeth in the inner left row and four teeth in the inner right row. Pharyngeal teeth rows in Iraqi cyprinids varied from one to three on each side. In certain cases, it was evident from the presence of a socket that a tooth had been lost. The count then included that tooth.
4) Fin rays
a) Dorsal and anal fins
Fin ray counts were divided into two types. One count is of spines or hardened soft rays or any unbranched, unpaired unsegmented rays and this is usually given in Roman numerals in the literature. In deference to some Iraqi unfamiliarity with Roman numerals, the spine count is given in Arabic numerals in this text. Spine count included rudimentary rays which, at the anterior dorsal and anal fins, may be obscured by flesh or scales requiring some probing or dissection. Radiographs were often useful to confirm counts made under a microscope. The second count is of soft rays and is also indicated by Arabic numerals. These rays are usually branched, flexible, segmented and laterally paired. The last two unbranched rays often arise from a single internal base and were then counted as one. This is generally the case in Cyprinidae. The branched ray count is the most diagnostic and variable in such fishes. Some families contain species with more than one dorsal fin. The first dorsal fin may be composed of spines and the second dorsal fin of spines and soft rays. In such species the count is given separately for each fin.
b) Caudal fin
The branched caudal fin rays only were counted. Dorsal and ventral to these central rays are a series of unbranched rays which become progressively smaller and may be obscured by flesh and scales where the caudal fin attaches to the caudal peduncle. Counts in other works often comprise the branched rays plus one dorsal and one ventral unbranched ray. Caudal fin ray counts are remarkably uniform within families. In Cyprinidae the count is almost always 17, except for occasional variants
c) Paired fins
Paired fin ray counts can be separated into unbranched and branched rays. A small splint in some species at the origin of the paired fins was excluded from the count. There is usually one unbranched ray which is not included in counts cited here. The branched ray counts were the most important and are the ones given here. However, in the pectoral fin the innermost rays were often difficult to discern and umbers may increase with age.
5) Scales
a) Lateral line count
The first scale counted was that scale contacting the pectoral girdle. The count continued along the flank following the pored scales and including small, additional scales lying between the large, regular scales as well as any unpored scales. The small, additional scales were relatively rare occurrences and any obviously abnormal fish - those with healed injuries for example - were not counted. The count terminated with the scale lying over the end of the hypural plate as determined by flexing the caudal fin. Some works recommend inclusion of a scale overlying the flexure only if most of its exposed field is closer to the body than to the caudal fin. Since the flexure of the caudal fin produces a relatively broad groove, this is difficult to judge in smaller fish. Therefore, the most posterior scale whose exposed surface touched the groove was the last scale counted. The count is also continued onto the caudal fin in some species for a total count as this sometimes proved useful in comparison with counts in older literature.
b) Scales above the lateral line
This count commenced with the scale at the origin of the first dorsal fin and continued down and back to, but not including, the lateral line scale. Any scale partially or wholly straddling the dorsal fin origin was counted as one scale. The count followed the natural scale row and included any small or irregular scales in the row.
c) Scales below the lateral line
This count commenced with the scale at the origin of the anal fin, followed the natural scale row up and forward to, but not including, the lateral line scale and included any small or irregular scales. In this, and the previous count, it sometimes proved necessary to shift the counting row because of the scale arrangement. This was always a backward shift. In some instances there were several scales at the anal fin origin which overlapped each other very closely. All these were counted and account for the large degree of variation in counts between individuals of some species.
d) Scales between the lateral line and the pelvic fin origin
This count was made as in the above count.
e) Predorsal scale rows
All rows of scales between the origin of the dorsal fin and the head were counted just below the mid-line of the back on the upper flank. The final "row" at the occiput may consist of a single scale. This method was used because scales on the mid-line may be small and irregular, obscured by heavy pigment, or absent.
f) Caudal peduncle scales
This was the lowest count of the scale rows around the caudal peduncle, usually at its narrowest point. Both lateral line scales were included. Scale rows were counted even when the scale arrangement was such that occasional alternate rows touched. This count may be quite consistent between individuals of a species, but it may also vary markedly. The variation depended on the presence of large scales dorsally and ventrally on the caudal peduncle connecting the flank scale rows. When such large scales were present bridging over the top and bottom of the caudal peduncle, the total count could be, e.g. 12, but in some individuals two or more smaller scales occupied their positions so that the scale count jumped to 16.
B) Morphometric characters
All measurements were to the nearest 0.1 mm using dial calipers. Measurements were taken on the left side unless a left fin, for example, was badly deformed or broken. Badly deformed specimens were not measured. Distortions due to preservation, such as a gaping mouth or expanded gill covers, were gently adjusted to as natural a position as possible. A list in Freshwater Fishes of Iran at www.briancoad.com explains how the various measurements were taken. All measurements were taken in a straight line and not over the curve of the head or body. Two basic measurements found in the text are total length, from the anteriormost part of the head to the tip of either lobe of the caudal fin when that fin is normally splayed, and standard length, from the anteriormost part of the snout (even when the lower jaw projects) to the end of the hypural plate (the end of the plate is found by flexing the caudal fin; in small fish it may be seen by shining a strong light through the caudal region). Standard length can be an inaccurate measurement. The end of the hypural plate is obscured by scales, flesh and caudal rays. Its position is determined by flexing the caudal fin; this flexure is taken to be the end of the hypural plate. Small fish have thin, delicate bones and the flexure may be at the anterior base of the hypural plate, at the origin of the caudal fin rays which articulate with and overlap the end of the hypural plate, or even between the last whole vertebra and the hypural plate. Large fish have a broad flexure which can give a variety of measurements by independent observers. Fortunately, in this study most fish were comparatively small and strong illumination helped to discern the end of the hypural plate. For larger fish an attempt at consistency was made.
The fresh waters of Iraq are contained in a single basin, the Tigris-Euphrates, shared with Turkey, Syria and Iran, occupying 915,000 sq km. Much of Iraq is, however, desert or semi-desert extending from the Euphrates to the borders of Syria, Jordan and Saudi Arabia at ca. 57% of the land surface. The basin comprises two main rivers, the Tigris to the east and the Euphrates to the west. The headwater catchment for the Euphrates lies in Turkey near Lake Van at an altitude of about 4500 m and the river runs for about 2700-3000 km. Its maximum average annual volume at Hit, Iraq is 35.9 billion cu m. The sources for the Tigris are distributed through Turkey, Iran and Iraq. Its main source is Hazar Lake in Turkey at 1150 m and it runs for 1840-2032 km. Its maximum average annual volume at Baghdad is 70.4 billion cu m. Only the Tigris River has significant tributary rivers within Iraq from the Zagros Mountains to the east. The lowlands of Iraq, known as Mesopotamia, the land between the rivers, have extensive marsh and lake habitats dating from the Middle Miocene (Prazak, 1978; Adams et al., 1999).
The fresh waters of Iraq comprise about 700,000-750,000 ha of which 44% is marshes, 39% is natural lakes, 13.3% is dams and reservoirs, 3.7% is rivers (Kitto and Tabish in www.enaca.org, downloaded 10 October 2005). The large marsh and lake areas are occasioned by the flat landscape which has a fall of 4 cm/km over the lower 300 km of the Euphrates and 8 cm/km along the Tigris. The alluvial delta of the Euphrates near Hit, Iraq is 735 km from the Gulf but only 53 m above sea level. The Tigris and Euphrates meander across the plain and end up partly as an inland delta (Partow, 2001; United Nations Environment Programme, 2003). Spring snow melt causes extensive flooding on the plains and is critical to the ecology of the marshlands centred on the confluence of the Tigris and Euphrates rivers in southern Iraq. A general, if somewhat dated, but detailed description of Iraq can be found in Mason et al. (1944) and a less detailed account in the CIA World Factbook for Iraq at www.cia.gov/cia/publications/factbook/geos/iz.html.
The climate of Iraq has been summarised by Al-Shalash (1966) and Taha et al. (1981) with a satellite overview by Kouchoukos et al. (1995). Iraq is semi-arid overall and is one of the hottest countries in the world. It has three climatic types - warm, temperate and rainy with a dry summer, a small area in the north; a dry, hot desert in the west; and a dry, hot steppe covering the central and southern parts. Extremes of temperature are not uncommon, reaching a low below -10ºC with a high above 50ºC in Mosul in the north while even Basrah in the warmer south has recorded -5ºC. The mean daily temperature for Mosul ranges from 6.9ºC in January to 33.9ºC in July; for Basrah 12.2ºC and 33.9ºC. For 10 stations across Iraq, the mean maximum temperature was over 42ºC for July and August. Evaporation from surface water bodies is therefore tremendous. The hottest months from June to September are essentially rainless. Most rain falls in winter and spring and is relatively slight with a mean annual total less than 250 mm. The annual total in a very small area of the northeast in the mountains has an annual total about 700 mm but in the southwest it is less than 100 mm. Much of central Iraq lies between the 100 and 300 mm mean annual rainfall isohyets and so lies outside the 400 mm minimum for dry farming. Irrigation farming is dependent on water from the main rivers with consequent effects on the fish fauna. Snow is an important factor in filling the rivers and marshes with water in spring and there are heavy snowfalls in the Zagros Mountains (some of which lie in Iran). The annual water regime of the Tigris-Euphrates has, therefore, two periods based on climate, the winter-spring flood period (December-July) and the summer-autumn low-water period (August-November). Even though Iraq contains large water bodies compared to other countries in the Middle east, arid and semi-arid conditions prevail.
The Tigris-Euphrates basin is the largest and most important river system between the Nile and the Indus. Details of its biology can be found in Rzóska (1980). The southern marshes have received much attention and are dealt with separately below, as are some studies of pollution as exemplars. Studies on geography, geology, limnology and pollution include a wide range of papers, listed here roughly in temporal sequence, except when by the same author when they are grouped together to avoid repetition of names:-
Howell (1922), Harrison (1942), Sousa (1944), Dimmock (1945), Sevian (1951), Fouad and Kholy (1952), Neumann (1953), Cressey (1958), Jacobsen and Adams (1958), Helbaek (1960), Mairakov (1964), Al-Hamed (1966c; 1976), Mohammed (1965; 1966; 1990), Oberlander (1968), Salonen (1970), Ubell (1971), Al-Saadi and Arndt (1973), Al-Sahaf (1975), Al-Saadi et al. (1975; 1989; 1989 (differing co-authors); 2000), Arndt and Al-Saadi (1975), van der Leeden (1975), Jernelöv (1976), Antoine and Al-Saadi (1982), Maulood et al. (1979; 1981; 1993), Sarker et al. (1980), Saad (1978a; 1978b), Saad and Antoine (1978a; 1978b; 1978c; 1982; 1983), Saad and Kell (1975), Kell and Saad (1975), Nomas (1988; 2005), Maulood and Hinton (1978), Prazak (1978), Mahmoud and Ahmad (1979), Zabid (1980), Al-Daham et al. (1981), Al-Hakeem (1981), Al-Issa (1981), Al-Saadi et al. (1981), Huq et al. (1981), Gerson (1982), Latif (1982), Latif et al. (1982), Schiewer et al. (1982), Al-Asadi (1983), Antoine (1983), Khalaf et al. (1983), Jead (1984), Ahmad and Hussain (1985), Almukhtar et al. (1985), Almukhtar et al. (1986), Al-Omar et al. (1986; 1989), Khayat et al. (1986), Mhaisen and Yousif (1986), Al-Ani et al. (1987), Al-Ansari et al. (1987), Al-Ramadhan and Pastour (1987), DouAbul et al. (1987; 1987; 1987 (differing co-authors); 1988), Salman (1987), Abaychi and Al-Saad (1988), Abaychi et al. (1988; 1991), Al-Ani (1988), Mohammad and Barak (1988), Al-Layla and Al-Rizzo (1989), Al-Mahdi and Abdullah (1989; 1996; 1999), Al-Saad and Al-Asadi (1989), Al-Saadi et al. (1989), Sabri et al. (1989), Al-Muddafar et al. (1990), Al-Robae (1990), Hassan and Awad (1990), Al-Imarah and Manther (1993), Al-Saad and Altimari (1993), Hardan (1993), Jamil et al. (1993), Al-Badran (1994), Al-Imarah and Jawad (1994), Al-Mousawi et al. (1995), Salman et al. (1999), Al-Manssory et al. (1998), Al-Badran et al. (1991), Al-Saad et al. (1993; 1995; 1996; 1997; 1997 (differing co-authors); 1998; 1998), Mohamed and Barak (1988), Al-Badran et al. (1991), Fawzi et al. (1991), Hussain et al. (1991, 1999, 2001; 2001 (different authors)), Jamil et al. (1993), Kostecki (1993a; 1993b), Al-Handal et al. (1994), Al-Imarah and Jawad (1994), Al-Muddafar et al. (1994), Hussein et al. (1994; 2000; 2001; 2002; 2002 (differing co-authors)), Jawad (1994), Al-Mousawi et al. (1995), Al-Saad et al. (1995; 1996), Kassim and Al-Saadi (1995), Mehdi et al. (1995), Mohamed et al. (1995), Al-Aubaidy and Al-Hello (1996), Al-Imarah et al. (1996; 1998; 2000), Al-Lami et al. (1996; 1998; 1998), Al-Mahdi (1996; 2001), Hussein (1996; 1998), Al-Mahdi and Salman (1997), Al-Imarah and Al-Kafaji (1998), Al-Lami et al. (1996; 1998), Al-Shaway (1998), Karim (1998a), Al-Hello (1999; 2001), Al-Maliki (1999), Al-Mudeer and Hassan (1999), Al-Sewech (1999), Al-Imarah et al. (2000), Al-Khafaji (2000), Hussein and Attee (2000a; 2000b), Hussein et al. (2000; 2002; 2002), Al-Imarah (2001), Al-Timari (2001), Ghliem (2001), Hussein (2001a; 2001b; 2002a; 2002b; 2005), Jassim and Hameed (2001), Partow (2001), Ramzy (2001), Albadran et al. (2002), El-Fadel et al. (2002), Haddadin (2002), Jaradat (2002), Kibaroğlu (2002), Mahdi et al. (2002), Ali (2003), Sultan et al. (2003), United Nations Environment Programme (2003), Schelle et al. (2004), Al-Badran (2004; 2005), Jacquet et al. (2005), Mutashar (2005), Neghamish and Ali (2005), Nilsson et al. (2005), Banat et al. (2006).
A series of articles in Archives of Polish Fisheries or Archiwum Rybactwa Polskiego (volume 9, supplement 1, 2001) are listed separately in the Bibliography of this work and contain descriptions of the environment and limnological information, namely Szcerbowski et al. (2001), Szcerbowski et al. (2001), Zdanowski et al. (2001a; 2001b), Sanecki et al. (2001), Kłosowski et al. (2001), Półtorak et al. (2001), Półtorak et al. (2001), Kornijów et al. (2001), Kornijów et al. (2001), Ciepelowski et al. (20010, Epler et al. (2001), Epler et al. (2001), Epler et al. (2001), Syzpula et al. (2001) and Pyka et al. (2001), among others.
Some larger works include Ionides (1937) who describes the river regimes of the Tigris-Euphrates basin, MacFadyen (1938) and Badry et al. (1980) the water supplies and El Kholy (1952) the hydrology of the Tigris River. Knappen-Tippetts-Abbett-McCarthy Engineers (1952), Laessøe (1953), Buringh (1957), Whyte (1961), Christensen (1993) and Morozova (2005) describe the physiographic regions, shores and irrigation systems on the lower Mesopotamian plain through history, and Al-Khashab (1958) the water budget of the Tigris-Euphrates basin before the more extensive dam construction and marsh drainage occurred. Al-Robaee (1990) reviews the surface water resources of Basrah province and Al-Khashab et al. (1983) the water resources of Iraq. Scott (1995) gives details of 31 wetlands in Iraq and Jawad (2003b) outlines the impact of environmental change on the freshwater fishes.
Many works on fishes cited in the Bibliography of this work contain information on the environment, habitats and pollution.
The Euphrates does not receive any tributaries within Iraq apart from seasonal runoff from wadis. The Tigris has four main tributaries from the Zagros Mountains, the Khabour (not the Khabour or Khabur of Syria, tributary to the Euphrates just north of the border with Iraq), the Great or Greater Zab (from Turkey, regulated by the Bakhma Dam, with 62% of its 25,810 sq km basin in Iraq and with 13.18 cu km at its Tigris confluence), the Little or Lesser Zab which drains a small stretch of mountains south of Lake Orumiyeh in Iran (74% of the 21,475 sq km basin is in Iraq, generates 7.17 cu km, of which 5.07 cu km is the safe yield after the Dukan Dam), and the Diyala which drains the western mountains of Kordestan (75% of 31,896 sq km in Iraq, 5.74 cu km at the Tigris confluence, the Derbendikhan Dam is in this river). Lloyd (1926) maps the boundary and rivers basins in this part of Iraq. There is also the Al Adhaim (or Al-Authaim or Nahr al Uzaym), a seasonal river rising in northern Iraq, draining 13,000 sq km and generating 0.79 cu km at its confluence with the Tigris, the Nahr at Tib, Dewarege (Doveyrich in Iran) and Shehabi rivers draining 8000 sq km and delivering about 1 cu km of highly saline water, and the Al-Karkha (Karkheh in Iran) draining 46,000 sq km and bringing 6.3 cu km into the Hawr al Hawizah during the flood season and into the Tigris in the dry season. A variety of dams have been built in Iraq for flood control, irrigation or power generation and are listed in Iraq Foundation (2003) and Nawab (1988). These provide additional lacustrine habitats for fishes as do the irrigation canals too, to some extent. The barrage at Ramadi across the Euphrates had a fish ladder as did those at Kut and Samarra on the Tigris although these were apparently not very effective (Lynch, 1956; Hatem, 1977). The Haditha Dam on the Euphrates River had no fish pass and fish accumulated at its base; these were caught with explosives (www.alemdhar.com, downloaded 22 November 2005).
The Tigris regime fluctuates much more than the Euphrates as the latter receives its water from more distant sources, rainfall being different too. The minimum recorded flow at Baghdad was 158 cu m/sec but the maximum was 13,000 cu m/sec (181-5200 cu m/sec for the Euphrates at Hit). Snow melt in March-May causes the high floods and then the rivers start to fall in June, reaching their lowest levels in September-October. The Tigris is a swifter river than the Euphrates with a more complex regime because of its tributaries. The Tigris in flood may discharge twice as much water per second as the Euphrates. The Tigris flood may peak a month or more before the Euphrates. The highest flood was 9 m on the Tigris in 1954 (Scott, 1995). The Tigris south of Baghdad can be up to 17 m deep but generally both the Tigris and Euphrates are comparatively shallow rivers, about 2-5 m deep (Rzóska, 1980).
The physical and chemical conditions in the Diyala River were studied by Jead (1984) who found conditions favourable for a wide range of fish species.
The Zagros Mountains form the eastern flank of Iraq and store water as snow. The higher peaks are snow-capped even in summer. Zard Kuh, for example, reaches 4548 m (32°22'N, 50°04'E). Rivers drain south and west to become tributaries of the Tigris River in Iraq or its confluence with the Euphrates River, the Shatt al Arab (known as the Arvand (= swift) Rud in Iran). The Shatt al Arab has a course variously given as 190 to 204 km to the head of the Arabian (= Persian) Gulf, is 250-2250 m wide and up to 24 m deep, and is navigable by ocean-going ships. It forms part of the Iran-Iraq border. The origin of the Tigris River is the Hazar Gölü of Elazig (38°41'N, 39°14'E) between the Murat Nehri and the Euphrates. It flows south-east, forming a short section of the border of Syria with Turkey, before entering Iraq to parallel, roughly, the course of the Euphrates River. It is a larger and swifter river than the Euphrates because of its left bank tributaries from Iran. The Tigris is over 1900 km long (1840 km and 2032 km are extremes cited in the literature). It is the 81st river in size in the world. The Tigris-Euphrates basin encompasses 884,000 sq km of which 27% or 238,500 sq km lies in Iran (Gleick, 1993); note that these figure vary widely between sources and Iran's contribution may be as low as 19%. The Tigris catchment is 166,155 sq km. It is an alkaline river (pH 7.8-8.2) with a total hardness of 200-350 mg/l. Water temperatures range from 8.5°C in January to 31.4°C in August. The flow pattern of the Tigris and its tributaries has a sharp peak in April at about 9 billion cu m, falling rapidly to about 1 billion cu m from September to October before beginning to rise again (Hatem, 1977). While the St. Lawrence River in Canada has a 1:2 ratio between low and high water, the Tigris has a 1:80 ratio (Cressey, 1958). The water level may fall by as much as 2 m over the summer. Interannual variation in spring flood levels are marked. Approximate streamflows over the past 6000 years are given by Kay and Johnson (1981) based on proxy data from palaeoenvironmental sources. They found an increase in streamflow over this period.
The main river of Iranian Khuzestan on the southern border with Iraq is the Karun, with a catchment of 67,340 sq km (Naff and Matson, 1984), a length of 820 km and a mean annual flow into the Shatt al Arab of 24.7 cu km. It now drains to the Shatt al Arab but once drained directly into the Arabian (= Persian) Gulf. Its discharge is comparable to the Euphrates (Binnie, 1950) and its contribution to the discharge of the Shatt al Arab is about 52% (Al-Manssory et al., 1998). Its sediment contribution is also significant an much of it is deposited in the Shatt al Arab (Salman et al., 1999). The annual suspended load of the Shatt al Arab north of the Karun entrance is 0.22 million tons and 20 million tons downstream of the confluence (Albadran et al., 2002). The Karun is described in more detail in Freshwater Fishes of Iran at www.briancoad.com. The combined Tigris-Euphrates-Karun in flood carries five times the load of the Nile (Fisher, 1968).
The Zagros consists of tightly packed ranges in the Tigris basin trending north-west to south-east. A trellis drainage pattern is imposed on this. The tangs, their formation and the drainage pattern are described by Harrison (1937) and Oberlander (1965; 1968a). These deep defiles may exceed 2400 m in depth with vertical walls of 300 m splitting anticlinal mountain ranges instead of taking apparently easier routes around their ends. They may well be barriers to the movement of less vagile fish species or a highway into the interior for those with some dispersal ability. Tangs formed because an antecedent drainage over lower relief was gradually uplifted at a rate slow enough to permit streams to cut through ridges and retain the original pattern of drainage once the softer material was washed out of the valleys between the anticlines. The uppermost parts of the basin show evidence of headwater captures and this orogenic zone is very unstable. The divide between endo- and exo-rheic basins is not the snowline of the Zagros but is east of it, so streams must first cross the Zagros peaks to start on their journey to the Arabian (= Persian) Gulf. Springs are important in the mountains, tapping aquifers and helping to maintain river flow. Serchinar Spring near Sulaimaniyah has mean temperature of 17.7ºC with a fluctuation of only 1Cº, pH 7.3, low turbidity, hard water and fish kills in late summer through oxygen depletion (Maulood and Hinton, 1978). Thermal springs are rare (Waring, 1965).
The southern areas of this basin are areas with high temperatures and large cities (Basrah in Iraq and Abadan in Iran), exacerbated by power plants such as the Al-Najebia on the Qarmat Ali Canal with an effluent water temperature of 41ºC (Hussein et al., 2001). Adjacent waters are highly polluted with sewage, agricultural waste and other chemicals (e.g. see Antoine and Al-Saadi, 1982; DouAbul et al., 1987, 1987, 1987, 1987, 1988; Al-Saadi et al., 1989; Arnove, 2000; Hussein et al., 2001). Mines and depleted uranium along with other substances are pollutants resulting from wars in Iraq. The increased use of motor boats has led to oil pollution. Scott (1995) records sale of Chloridrin, a persistent insecticide, to residents of the Hawr al Hawizah in Iran as a means of poisoning large numbers of fish for sale. Phytoplankton blooms are common and in canals the chlorosity increases, transparency decreases and pH is reduced because of the dying plant material. The Shatt al Arab is more affected by physical factors as it is an estuary. Historical problems with salinisation of soils (and presumably water) and siltation extend back 5000 years in southern Mesopotamia, a consequence of over-irrigation and inadequate drainage (Cadoux, 1906; Laessøe, 1953; Buringh, 1957; Jacobsen and Adams, 1958; Goldsmith and Hildyard, 1984; Christensen, 1993). The irrigation systems rose and fell with the vicissitudes of history as did the available habitats and the water quality for fishes.
Marshes
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The devastation of the southern marshes of Iraq (al ahwar in Arabic) as an ethno-political weapon, with consequent deleterious effects on the fish fauna, has been widely reported and documented in both the scientific and the popular literature. There are also significant affects on the marine environment of the northern Gulf (e.g. Al-Ghadban et al., 1999; Saeed et al., 1999). Various proposals have been put forward to remedy the situation in whole or in part. A full listing of all these popular articles is not possible and they do tend to be repetitive. A selection follows and includes older descriptions of the marshes as well as recent analyses of change; a general description of the marshes is based on them: - Willcocks (1912), Maxwell (1957), Philby (1959), Salim (1962), Young (1983, 1989), Thesiger (1985), Nomas (1988; 2005), Dugan (1993), North (1993), Pearce (1993, 2001), Scott and Evans (1993), Al-Bayati (1994), AMAR (1994), Banister et al. (1994), Cole (1994), Maltby (1994), Ryan (1994), Scott (1995), Munro and Touron (1997), Mitsch et al. (2000), Partow (2001), Nicholson and Clark (2002), Ali (2003), Carpenter and Ozernoy (2003), Eden Again Project (2003), Furlow (2003), Iraq Foundation (2003), Joosten (2003), Lubick (2003), Molavi (2003), Randerson (2003), Stevens and Alwash (2003), Stevens et al. (2003), Alwash et al. (2004), USAID (2004), Alwash and Cattarossi (2005), Castro (2005), Farhan (2005), Fink (2005), Ghadiri and Ghadiri (2005), Hussain et al. (2005), Hussein (2005), Iraqi Ministries of Water Resources, Municipalities and Public Works and Environment (2005), Jacquet et al. (2005), Khalaf and Al-Mukhtar (2005), Lawler (2005), Partow (2005), Richardson (2005), Richardson et al. (2005), Stevens et al. (2005), Richardson and Hussain (2006), Banat et al. (2006), Hammer (2006), Al-Najim (no date), as well as numerous research papers on fishes.
Various websites give colour satellite maps of the marshes, their desiccation and partial recovery. Some of the marshes can be seen with Google Earth but the United Nations Environment Programme (UNEP) in particular shows colour images from satellites in their Iraqi Marshlands Observation System (IMOS) ( http://imos.grid.unep.ch/) as well as numerous images of the marshes themselves, and also UNEP documents. Another point of entry to sources of information is the Marshlands Information Network (MIN) at http://jp1.estis.net/communities/min_eng/. Reiss et al. (2003) give an interim status report on the marshes and illustrate the path of the various diversionary canals and dams that directed water away from the marshes.
The construction of dams upstream in Turkey and the large scale, modern drainage programmes in Iraq bordering Iran such as the "Three River Project" are drying up the extensive marsh systems and these are regarded as an eco-disaster leading to desertification in Iraq and adjacent regions of Iran (North, 1993; Pearce, 1993, 2001; Ryan, 1994; National Geographic, 185(4):unnumbered page, 1994; Scott, 1995; Munro and Touron, 1997; Maltby, 1999; Partow, 2001; www.amarappeal.com/documents/Draft_Report.pdf, downloaded 15 November 2001). The 32 km long "Fish Lake" was constructed as a barrier to Iranian attacks on Basrah. The Iranians dug several drainage ditches from "Fish Lake" northeast of Basrah to the Karun River, to dry up land for infantry attacks on Basrah. This whole marsh area of about 17,000 sq km, is the most important wetland in the Middle East and one of the top ten in the world. The Central and Hawr al Hammar marshes in Iraq by 2001 have had 97% and 94% of their land converted into bare ground and salt crusts. Less than one-third of the Hawr al Hawizah (= Hawr al Azim in Iran) survives. It was estimated in the 1990s that the marsh area would be a desert within a decade and this seems to be an accurate assessment. The effects on the fishes in Iraq are unknown but much habitat is being lost which could have served as a reserve against loss in Iraq through natural and man-made changes.
The marshes were a complex system of rivers and channels, permanent open water (sometimes referred to as lakes), ponds (bogs), permanent and seasonal wetlands, mudflats and desert. Depending on the natural variation in flooding, these all interconnected and overflowed in complex patterns. For convenience, three main areas are recognised, the Hawr al Hammar, the Central (or Qurnah) Marshes and the Hawr al Hawizah. Hawr al Hammar lies mostly south of the Euphrates River, is about 120 km long and 25 km wide at its maximum, the largest water body on the lower Euphrates. The permanent marsh and lake encompassed 2800 sq km, flooding to 4500 sq km. The lake is eutrophic and slightly brackish because of its proximity to the tidal influence of the Arabian (= Persian) Gulf. Maximum depth at flood is about 3 m, 1.8 m at other times. It is fed principally by the Euphrates and with overflow from Central Marshes, and drains into the Shatt al Arab. The Central Marshes lie north of the confluence of the Tigris and Euphrates rivers, north of the Euphrates and west of the Tigris. It is mostly fed by Tigris distributaries and covers 3000 sq km, flooding to 4000 sq km. Permanent lakes in the centre of the marshes are about 3 m deep. The Hawr al Hawizah lies to the east of the Tigris River and cross the Iraq-Iran border, being known as the Hawr al Azim in Iran. In the west they are fed by two main distributaries from the Tigris, the Al Musharah and Al Kahla, but may be fed directly from the Tigris at flood time. The marshes are also fed by the Karkheh River from Iran. They encompass an area of at least 3000 sq km, 5000 sq km in flood. The northern and central parts of the marshes are permanent but the southern sections are more seasonal. Large and permanent lakes are up to 6 m deep. The marshes drain to the Shatt al Arab via the Al Swaib River.
The permanent marshes are dominated by common reed, Phragmites australis, with reed mace, Typha domingensis, in the seasonal zones. Permanent lakes have hornwort, Ceratophyllum demersum, eel grass, Vallisneria spiralis, pondweed, Potamogeton crispus and P. nodosus., stonewort, Chara sp., water lilies Nymphaea indica and N. alba, duckweed Lemna gibba, and other plants. Various piscivorous birds (Dalmatian pelican, pygmy cormorant, etc.) thrive here along with a wide variety of waterfowl.
Lowlands may be inundated for more than 100 days. Early accounts of floods in Mesopotamia, dating back to Sumerian times almost 5000 years ago, are discussed by Mallowan (1964). Floods can encompass close to 100,000 sq km in Iran and Iraq at the head of the Arabian (= Persian) Gulf (Naff and Matson, 1984). The water level in the Tigris River can rise a at a rate of over 30 cm/h (Grego et al., 2004). Progressive clearing of woodland over the last 7000 years increased runoff, causing higher and more severe floods, soil erosion, increased turbidity in streams and higher sedimentation (Wagstaff, 1985; Hussein, 1996, 1998). Aridity also seems to have been a factor (Roberts and Wright, 1993). Erosion is three times the world standard rate at 30 tonnes/hectare and will rise twofold over the next ten years (IRNA, 20 December 1998; Hussein, 1998). All these must have, and continue, to affect the fishes in this and other basins, favouring those species able to cope with these conditions.
The following account of the drainage schemes around the marshlands of southern Iraq is taken from Partow (2001) which should be consulted for the coloured satellite maps. Major drainage works in southern Iraq were initially planned and undertaken to reduce salinisation resulting from irrigation agriculture and for sewage discharge. Construction of the Main Outfall Drain (later called the Third River or Saddam River) began in 1953 and extended into the 1990s. The MOD runs for 565 km from just south of Baghdad to Al Nasiriyah on the plain between the Tigris and Euphrates. It then passes under the Euphrates in siphon pipes, passes around most of the Hawr al Hammar but cutting through its southeastern section in a raised embankment and then joins the Shatt al Basrah Canal which drains to the tidal inlet, Khawr az Zubayr, an arm of the Arabian (= Persian) Gulf. The physico-chemical conditions in the northern part of the Saddam River were found to be within acceptable levels for fish (Al-Mahdawi et al., 1995). The southern Saddam River is close to marine waters in its hydrochemical characteristics but is naturally affected by the competing influence of upstream fresh waters from the Hawr al Hammar and downstream saline waters of the Khawr az Zubayr (Karim, 1998). Ghany (1988) and Al-Handal et al. (1994) studied ecology, seasonal variation in nutrients and limnology of the Shatt al Basrah. The emphasis shifted from irrigation drainage to marsh drainage as a means to reclaim land and later to eliminate the marshes as a refuge for government opponents. A dam was built near the siphons to divert Euphrates water into the MOD and an embankment was built to prevent overflow of the Central Marshes into the Hawr al Hammar. This led to the drying of the Hawr al Hammar, especially since the Ataturk Dam in Turkey had already reduced the flow of the Euphrates. Additionally, the Al Qadisiyah River was constructed in 1993, diverting the water from the Shatt al Atshan, a branch of the Euphrates into the Al Sulaybiyat depression where the water evaporates. Other major water diversions include the Mother of Battles River (Umm al-Maarik) completed in 1994 which runs from near the MOD siphons, parallels the MOD for 108 km and discharges into the embanked southeast Hawr al Hammar and the Fidelity to the Leader River (Wafaa lil-Qaid) which is 90 km long and carries water from the MOD to the south of Basrah.
The eastern Central Marshes had partially dried in 1990 because of construction of causeways built for transport in the Iran-Iraq War. The distributaries from the Tigris were captured by a 1-2 km wide west-east canal along the northern border of the marshes. This canal then joins the Prosperity River (Nahr al-Izz), 50 km long and 2 km wide running north-south to discharge into the Euphrates near its confluence with the Tigris. The two canals block recharge of the Central Marshes and the Medina Dam on the Euphrates west of its junction with the Prosperity River blocked any backflow into the marshes. Another river, the Crown of Battles (Tajj al-Maarik) to the north diverted Tigris River water from the Central Marshes to the Hawr al Hawizah. Both the Hawr al Hammar and Central Marshes were divided into polders and diked, and canals were built to dry and drain them more quickly.
The Hawr al Hawizah was less affected but even there distributaries form the Tigris were canalised such that they discharged deep in the marshes and the northwestern shores dried out. The Aybas Canal desiccated the southern Hawr al Hawizah by re-directing water from the marsh into the Shatt al Arab near the Tigris-Euphrates confluence. Canals and polders have been constructed to drain the marshes and facilitate evaporation. Iran has a large dam on the Karkheh River which began to fill in 2000 and will be used for irrigation. This further reduces flow into the Hawr al Hawizah and irrigation return water may well be salty and of poor quality.
The Karkheh River is 320 km long, but is lost in the Hawr al Azim of the Tigris after draining 43,000 sq km. These marshes straddle the Iran-Iraq border and are called Hawr al Hawizah in Iraq. The Karkheh flow was depleted by 70% in 2001 during a drought and it was thought that this river might dry completely (Foltz, 2002). The marshes along the Karkheh River, with oxbow lakes and riverine forest, are a habitat now rare in southern Iran and Iraq outside protected areas. The Karkheh Dam, 20 km northwest of Andimeshk, has a crest 3030 m long, a height of 127 m and is the sixth largest dam in the world with a capacity of 7.8 billion cu m, nearly a third of the total dam capacity for Iran. The dam is meant to produce electricity, for fish farming and to control floods and drought (IRNA, 17 April 2001; 19 April 2001; Aftab Yazd, Tehran, 346(18 April 2001); Sadegi, 2003). The Karkheh Dam is planned to carry water via pipeline over land (330 km in length) and under the sea (210 km) to Kuwait. The supply rate would be 200 million gallons per day (Partow, 2001) or 300 million cu m (www.irna.com, downloaded 29 January 2003). A dam has been built by Iran across the Hoveyzeh Marsh (Hawr al Hawizah) to retain water on the border with Iraq. All these factors have obvious consequences for the marshes shared with Iraq.
Almost 5800 sq km of marshes in 1970 shrank to about 500 sq km in 2002 but by August 2005 the area was back up to 2200 sq km, although this flooded area was not fully recovered ecologically (www.theglobeandmail.com, downloaded 24 August 2005). Richardson and Hussain (2006) give a progress report on recovery which is generally positive but warn that two years of good-quality water entering the marshes resulting from snow-pack melt in Turkey and Iran may not obtain in the future and restoration may only be partial. Partow (2001) cites 8926 sq km in 1973-1976 (extending to 20,000 sq km during flood season) reduced to 1297 sq km by 2000. The Central Marshes were completely devastated with 97% of the land dried up, the Hawr al Hammar was 94% bare land but the Hawr al Hawizah (Hawr al Azim in Iran) retained somewhat less than a third of its former size. This last area did better because it is fed by the Karkheh River from Iran.
The marshes used to account for 60% of Iraq's inland water fish catch (Maltby, 1994). The catch in the Hawr al Hawizah in April 2005 was dominated by Barbus luteus, B. sharpeyi and Carassius carassius (probably C. auratus)(www.iraqmarshes.org, downloaded 29 August 2005). The number of fish species in the marshes during the beginnings of recovery were 27-36% of historic surveys although not all the smaller species were probably captured nor were marine entrants found occasionally. Barbus sharpeyi was at only 30-40% of historic body lengths and Carassius carassius (probably C. auratus) introduced from Iran formed up to 46% of captures. Silurus triostegus comprised up to 60% of the catch and, as a scaleless species, is not eaten by the local Shi'a. The dominance of this predator is due to prolonged marsh drying and an absence of algae and aquatic plants on which Barbus spp. fed (Richardson et al., 2005). The Hawr al Hammar had 72% of the historic number of fish species according to Richardson and Hussain (2006).
The east Hawr al Hammar is under tidal influence from the Shatt al Arab and in April 2005 had a salinity of 2.4-2.6 p.p.t., slightly higher compared to previous records (www.iraqmarshes.org, downloaded 29 August 2005). In February 1978, Maulood et al. (1979) found salinities less than 1.0 p.p.t. in the marshes and Shatt al Arab, slightly exceeding 1.0 p.p.t. at depth and only attaining a salinity of 29.5 p.p.t. at sea under a freshwater plume with 0.72 p.p.t. This was at a time of increased freshwater flow in winter. Marsh and Shatt al Arab pH was7.7-8.5 and oxygen ranged from 3.8-7.0 mg/l.
The Al-Khafigiea (or Hawr-e Susangerd in Iran) at 31°45'N, 47°55'E are northwest of Ahvaz near the Iraqi border and form the extreme eastern edge of the Hawr al Azim, most of which lies in Iraq. The marshes occupy about 30,000 ha and are made up of permanent and seasonal fresh and brackish marshes and seasonally flooded arable land. The marshes are on the floodplain of the Karkheh River. Irrigation projects, grazing by livestock, reed cutting and fishing all occur here. Parts of the marsh were damaged by the Iran-Iraq War. The Iran-Iraq marshes declined in area from 1089 sq km to 758 sq km from 2000 to 2002 and was predicted to dry up in 5 years from 2002 because of the Karkheh Dam. Reports conflict since once the dam was full, a relatively normal flow regime would help maintain the marshes.
The lower Mesopotamian Plain narrows towards the Arabian (= Persian) Gulf to less than 45 km wide occasioned by the large alluvial fan of Wadi Batin and the Al Dibdibah plain from the west and the Karkheh and Karun rivers from the east with their heavy silt loads. This prevents the Tigris and Euphrates from flowing directly to the sea and they deposit their sediment inland to form the marshes. However the flow of the Karun has been regulated recently and its discharge and sediment contribution has been reduced significantly (Albadran, 2004).
As lowlands at the head of the Arabian (= Persian) Gulf receive waters from this vast drainage basin, floods occur, increasing the depth and extent of marshes. Floods occur in late winter and spring from increased rainfall and snow melt. Flood waters may increase depths by 1-1.5 m, with 2-3.5 m in more permanent basins.
Marsh temperatures generally range from 15°C in January to 31°C in August and fish may retreat to deeper areas or move upriver at the higher temperatures. The first marsh area reflooded, Abu Zirig on the western side of the Central Marshes, had a temperature range of 11-39.9ºC in its southern sector (Mohamed et al., 2005). Flooded marshes tend to be warmer than rivers in winter. Marshes also tend to be more saline than rivers due to evaporation and agricultural runoff.
The principal, larger marsh species familiar to fishermen are Acanthobrama marmid, Alburnus mossulensis, Aspius vorax, Barbus sharpeyi (a keystone species), B. grypus, B. luteus, B. xanthopterus, Carassius auratus, Ctenopharyngodon idella, Cyprinion macrostomum, Cyprinus carpio, Liza abu, and Silurus triostegus. The introduced Ctenopharyngodon showed some competition with native Barbus sharpeyi as juveniles with similar diets on filamentous algae, diatoms and plant remains (Faddagh and Al-Mukhtar, 2005). Stocking of the marshes through the USAID's Agriculture Restoration Program for Iraq (ARDI) had plans to buy one million fish fingerlings from hatcheries in Basrah and Babil and release them in Basrah and Dhi Qar marshes. Approximately 225,000 fingerlings were released 3 July 2006 in the Hawr al Hammar (US Department of State, 2006).
Studies in the recovering Hawr al Hammar in 2005-2006 showed a fauna of 31 species, 14 native freshwater fishes (including Acanthobrama lissneri, presumably a mis-identification), 6 exotic freshwater fishes (including Carassius carassius, presumably C. auratus and Poecilia sphenops, presumably P. latipinna), and 11 species of marine origin (Hussain et al., 2006). Resident species (present for 9-12 months) numbered 10, seasonal species (6-8 months) numbered 5 and occasional species (1-5 months) numbered 16, indicating a low diversity. The number of species was lowest in December at only 5 species and diversity increased in March-April and in July, which was the highest at 22 species. The most abundant captures in terms of individuals were Liza abu (35.85%), Carassius carassius (23.6%)(probably C. auratus), Acanthobrama marmid (10.79%), Tenualosa ilisha (10.05%), Thryssa mystax (possibly T. whiteheadi), Alburnus mossulensis, Cyprinus carpio, Aspius vorax, Barbus luteus, Liza subviridis, Silurus triostegus, and Heteropneustes fossilis. Captures of ten species numbered less than 10 individuals.
Hussain et al. (2006) also examined the Hawizah Marsh and found 15 species, 12 being native and 3 exotics (none of marine origin). Resident species numbered 9, seasonal species3 and occasional species 3. The number of species was lowest in December at 5 species and diversity increased in March-April, in July and September, the latter two being highest at 13 species. The most abundant species in terms of individuals were Liza abu (37.1%), Barbus luteus (29.4%) and Carassius carassius (15.3%)(presumably C. auratus). The remaining species all numbered less than 5% each. The Al Kaba'ish (Chabaish) Marsh had 14 species, 10 being native and 4 exotics. Resident species numbered 8, seasonal species 1 and occasional species 5. The highest number of species was found in June at 11, and the lowest in December at 6, with diversity increasing in June-August and February-April and decreasing in November-January. The most abundant species in terms of individuals were Liza abu (61.9%), Carassius carassius (19.7%)(presumably C. auratus). The remaining species all numbered less than 4% each.
Shatt al Arab
The Shatt al Arab (river) has been studied extensively for its importance as a fish habitat, its proximity to the marshes and because of a local concentration of scientists at the University of Basrah. The limnology of the Shatt al Arab is covered by a range of papers listed above, with one particular author being Saad and collaborators. The river is up to 500-700 m wide downstream of the Karun River, has a tidal range of 1.8 m at Basrah and is 8-15 m deep below Basrah (Al-Ramadhan and Pastour, 1987). The Shatt al Arab is under some tidal influence up to 110-140 km from the mouth (sources differ; see also Al-Ramadhan and Pastour (1987)). Its waters are therefore strongly mineralised. Salinity varies with distance from the sea but the freshwater input from the Karun River of Iran can make even its lower reaches fairly fresh, around 5‰ (Mohamed et al., 2001). The salinity situation is complicated by the input of agricultural runoff from upriver which is often salinised, by precipitation regimes far away in the mountains of Iran and Turkey (snow melt April to June, least flow September to November), local seasonal rainfall (December to March), by withdrawal or withholding of water for industry, irrigation and power generation in all the upriver dams, by seasonal evaporation from open water bodies, and by recent changes in flow patterns associated with the draining of the southern marshes. Nutrient salts increase towards the mouth (Al-Aubaidy and Al-Hello, 1996). Al-Hassan and Hussain (1985) described hydrological parameters affecting the penetration of marine fishes into the Shatt al Arab, Hussain et al. (2003) the small fish assemblage and Mohamed et al. (2001) the whole estuarine ichthyofauna, where water temperature, transparency and salinity correlate positively with number of species and individuals. A total of 44 species in 23 families were found. The estuary is an important nursery and feeding ground for marine species (some of which enter fresh water) as turbidity provides a measure of protection from predators and detritus serves as food (Ahmed and Hussain, 2001). The intertidal mudflats of the estuary has a fish assemblage of 34 species which shows seasonal fluctuations as salinity varies with the flood regime (Hussain et al., 1999). Salinity at Al Faw (= Fao) fell as low as 0.7‰ and the mouth of the estuary to 0.9‰, with such freshwater fishes as Cyprinus carpio being abundant, and Silurus triostegus, Barbus xanthopterus, B. sharpeyi, B. kersin, Acanthobrama marmid, Garra variabilis and Liza abu being present. Most fish were resident euryhaline or marine species, represented by juveniles, or the anadromous Tenualosa ilisha on its way to spawn in fresh water.
It is an important source of nutrients for the Arabian (= Persian) Gulf (Abaychi et al., 1988) and for the production of fishes there. Crops are irrigated by means of the tidal rise which is used to push fresh water into the fields (Harrison, 1942; Binnie, 1950; Gholizadeh, 1963; Gholizadeh and Fatemi, 1969). This has obvious effects for the fish fauna and its composition as well as for increased salinisation of habitats. There are appreciable diurnal and seasonal fluctuations in physico-chemical conditions. The Shatt al Arab has temperatures of 32°C in August and 10°C in January but there is little or no vertical stratification (Arndt and Al-Saadi, 1975). Tidal waters probably penetrated far inland through the Holocene as evidenced by faunal remains in boreholes of the Hammar Formation (MacFadyen and Vita-Finzi, 1978).
Hussain et al. (1989, 1997) described the composition of the fish fauna in the Shatt al Arab near Basrah but sampled different areas for these two studies, the latter study being on side channels. In 1982-1983, five species formed 44% of the total specimens collected out of 33 species. These were Nematalosa nasus, Gambusia holbrooki, Liza abu, Acanthopagrus latus and Heteropneustes fossilis. Seasonal variations occurred in the number of individuals and species. In 1992 and 1993, six freshwater species formed 96% of the assemblage of small fishes (25 species in 13 families). Acanthobrama marmid was dominant (70.8%) with Liza abu, Aphanius dispar, Alburnus mossulensis, Barbus luteus and Garra rufa constituting 7.5, 5.2, 4.4, 4.3 and 4.1% respectively of total fish captured. Seven marine species made up 2.1% of the assemblage. An increase in the Tigris River discharge decreased salinity in the Shatt al Arab: previously marine species were common at Basrah in Iraq but they became rare, Carassius auratus appeared in Basrah fish market and Cyprinus carpio was caught in large numbers down to the estuary (N. A. Hussain, in litt., 1994). Hussain et al. (2004) described the fish community in the Al-Khandak branch of the Shatt al Arab which passes through Basrah and receives large amounts of domestic sewage. They found three major fish groups (Aspius vorax and Tenualosa ilisha), (Liza abu and L. carinata) and (Alburnus mossulensis, Acanthobrama marmid, Cyprinus carpio and Aphanius dispar). Another group, consisting of Barbus luteus and Garra rufa, tended to switch from one group to another according to the pollution and environmental conditions, as did some members of other groups. The Al-Khandak branch is now barren of fish (observation by S. Hussein, 14 November 2006). Hussain et al. (2003) described the small fish assemblage in the estuary of the Shatt al Arab.
The fish assemblage in the upper reaches of the Shatt al Arab showed a decline in biodiversity over three periods, 1982-1983, 1992-1993 and 2003-2004 (Partow, 2005). In the first period five species comprised 44% of the population (Nematalosa nasus 13.3%, Gambusia holbrooki 8.6%, Acanthopagrus latus 8.2% and Heteropneustes fossilis 5.7%). Note that Gambusia and Heteropneustes are exotics and not part of natural fauna and the two other species are marine. In the second period Acanthobrama marmid, a native freshwater species, dominated at 70.7%. Barbus species almost disappeared because of a sensitivity to pollution. In the third period four species comprised 97.7% of the catch, namely Liza abu (58.0%), Tenualosa ilisha (19.4%), Carassius carassius (sic, probably C. auratus) (10.5%) and Liza carinata (9.8%). Liza abu is a native freshwater fish which is tolerant of high temperatures and salinities and Tenualosa and L. carinata are marine species tolerant of pollution and varying conditions
The Shatt al Arab was the sole waterway connecting Iraqi fresh waters with the Arabian (= Persian) Gulf. The Shatt al Basrah Canal was constructed in 1983 between the Euphrates River, after its emergence from the lower Hawr al Hammar, and the Khawr az Zubayr, a 40 km long marine inlet. The Shatt al Basrah Canal is 37 km long, 59 m wide and 5-7 m deep. The fauna of the Khawr az Zubayr was surveyed by Al-Hassan and Muhsin (1986), Hussain et al. (1988; 1994), Ali and Hussain (1990) and Nasir (2000). It is mostly a marine fauna but during February and March, flood waters released from a dam freshen the upper reaches of the khawr which then has a salinity of 2-12‰ and such species as Barbus grypus, B. luteus, B. sharpeyi, Cyprinus carpio and Silurus triostegus can be found. Freshwater species found in estuarine conditions (salinity unspecified) were Liza abu, Heteropneustes fossilis and Alburnus capito (presumably A. mossulensis). The fauna of the Shatt al Basrah Canal was examined Al-Daham and Yousif (1990). The salinity of the Canal varies with tidal range, level of water in the Euphrates and amount of water released by a water regulator 22 km from the Canal entrance. Three stations were sampled, one near Hawr al Hammar (salinity range 1.0 to 3.5‰ from March to October), one three-quarters of the way from the hawr to the khawr (1.0 to 24.4‰ from March to November), and one at the end of the Canal near the Khawr az Zubayr (14.8 to 33.0‰ from March to October). Water temperatures ranged from 10ºC in January to 33ºC in August, Secchi disc readings from 8 cm in June to 101 cm in April, pH from 7.4 in October to 9.0 in April, and total suspended solids from 1.7 g l-1 in March to 48.4 g l-1 in January. Forty-seven species were recorded. Liza viridis was the most abundant species at 59.6% of total numbers and 40.0% of total weight followed by Acanthopagrus latus at 7.08% and 10.92%. Thryssa malabarica (possibly T. whiteheadi) and Aspius vorax accounted for over 10% of total numbers but less than 3% of total weight. Barbus luteus and B. sharpeyi accounted for over 11% of total weight but less than 3% of total numbers. As expected the more marine station near the Khawr az Zubayr was dominated by marine species and the station near the Hawr al Hammar by freshwater species and euryhaline marine species. Of 15 species designated as freshwater fishes, 14 were captured at station 1, nine at station 2 and 5 at station 3; these latter being Aspius vorax, Barbus luteus, Alburnus orontis (= A. mossulensis), Liza abu and Heteropneustes fossilis. A side channel of the Khawr az Zubayr was investigated as a site for fish culture but was found unsuitable because of a reducing environment (Al-Baddan et al., 1991).
Canals, dams and lakes
Canals, and other irrigation structures, have long been a feature of the Mesopotamian plains, forming habitats for fishes dating back thousands of years. Their loss through natural and man-made disasters must have affected fish populations but sufficient natural habitat remained to ensure survival.
A network of canals existed in the Abbasid period ca. 850-1000 A.D., irrigating dry areas and draining areas liable to flood (Hatem, 1977). The Hindiyah barrage was completed in 1913 and diverted Euphrates River water into reconstructed irrigation canals that dated back to mediaeval and ancient times (Nomas, 1988). The natural system of water distribution in Iraq was first changed significantly in modern times by construction of the Ramadi barrage in 1951 (Partow, 2001). This diverted water from the Euphrates into the Habbaniyah depression (Habbaniyah or Habbaniya Lake) and, with excess flow, into the Abu Dibbis and Bahr al Milh depressions forming brackish Lake Razzazah (Razazza or Razazah). Lake Habbaniyah had an important commercial fishery, and Razzazah is also used for fishing (Scott, 1995) and was the site for introduction of mullets from Khawr az Zubayr and Khawr Abdullah (Mohamed et al., 2001). The salinity of Lake Razzazah precludes spawning of some fish species. Abu Dibbis was twice a brackish lake in the Quaternary but dried out with increasing aridity (Voûte and Wedman, 1963). The Samarra barrage constructed on the Tigris in 1954 diverted floods into the Tharthar depression to protect Baghdad. Tharthar Lake is 50 m below the level of the main rivers and 4 m below mean sea level (Voûte and Wedman (1963). The early 1960s saw the construction of the Dukan or Dokan Dam (270 sq km) on the Little Zab River and the Derbendikhan Dam (140 sq km) on the Diyala River, both about 75-85 m deep. There are at least 26 planned and operational dams and barrages of some size in Iraq. These lakes and dams now support fish faunas.
The Dukan Dam has been studied by Al-Hamed (1976) who considered it a principal source for fish in northern Iraq. At high water the reservoir covers 270 sq km and at low water 48 sq km. Surface water temperatures had a range of 24-30ºC and the lake was thermally stratified. Fifteen fish species were recorded from the reservoir. The authors in the Archives of Polish Fisheries supplement (see above for list) give further details on this dam as well as the Derbendikhan Dam, Habbaniya Lake (184-426 sq km, maximum depth 13 m), Tharthar Lake (1875-2223 sq km, maximum depth 68.4 m) and Razzazah Lake (1050-1700 sq km, maximum depth 17 m). The lake and dam areas and levels oscillate through spring inflows, evaporation in summer, irrigation requirements and power generation for the dams. The lowest levels are in fall and early winter. Dukan, Derbendikhan and Tharthar are monomictic with high water visibility in the 5-9 m range. Lack of thermal and oxygen stratification occurred only in the shallow Habbaniyah and Razzazah lakes. Salinity in lakes Habbaniyah, Tharthar and Razzazah was 0.2‰, 2‰ and 11‰ respectively, the last lake having no outlet and receiving accumulated salinisation products from irrigation agriculture. Benthivorous fish had the most suitable conditions in terms of macrozoobenthos density in Razzazah followed by Habbaniyah and Tharthar. Epiphytic fauna is an important fish food and may be more important than zoobenthos in some instances.
Upriver dams
The water supply of Iraq is heavily dependent on sources lying outside that country. A variety of popular and scientific articles have been published on these water resources and the potential for conflict between the countries harbouring or relying on the water. Only a selection is quoted here as the problems remain the same. References include Beaumont (1978, 1981), Naff and Matson (1984), Kolars and Mitchell (1991), Roberts (1991), Morris (1992), Hardan (1993), Kolars (1993), Rowley (1993), Tomanbay (1993), Wakil (1993), Biswas (1994), Scott (1995), Shapland (1997), Beaumont (1998), Cunningham (2000), Çarkoğlu and Eder (2001), Kocher and Weidenhöfer (2001), Haddadin (2002), Altinbilek (2004), and Google Earth shows the size and extent of the dams.
Agriculture in Iraq depends on the water of the Tigris and Euphrates rivers and hydraulic irrigation has been practiced for at least 6000 years. These water diversion schemes have had effects on the fish fauna but in the past there was usually enough water to make the main rivers refuges for fishes at the height of the dry season. However in the mid-1960s, Turkey began construction of a series of dams as did Syria in the 1970s. Initially, dam construction had little effect on Iraq but later dams extracted 45% of the pre-1974 flow of the Euphrates into Iraq when Iraq itself had higher demands for its own irrigation. A further complication is the water quality; Iraq has salinisation problems and upriver irrigation will only add to this. Some transfer of Tigris River water via the Tharthar basin helps ameliorate the problem as this is better quality water. The water in the Euphrates river is 88% controlled by Turkey, 9% by Syria and only 3% by Iraq. For the Tigris River, Turkey controls 56%, Iran 12% and Iraq 32%. Flows into Iraq in 2005 were about a third to half what they were 12 years ago (C. Reed in www.harvard-magazine.com, downloaded 19 September 2005; United Nations Environmental Programme, 2003).
The Southeast Anatolia Project (known as GAP after its Turkish acronym) in Turkey includes 20 dams and 17 hydro-power plants, reducing the flow of the Euphrates River by up to 90% (www.thestar.com, downloaded 4 July 2004)(other sources cite 21 and 19 respectively, but in any case very extensive water diversion and flow management). The Tigris-Euphrates basin as a whole has more than 30 major dams. GAP includes the massive Ataturk Dam on the Euphrates completed in 1993. It plans to draw off one-third of the waters originating in Turkey and will also use water from the Tigris River (Ottawa Citizen, 10 November 1994; Morris, 1992; Biswas, 1994; Beaumont, 1998; Al-Najim, no date). The reduction in flow for Iraq may reach 60-90% (sources vary on the amount), especially when water is taken from the Euphrates or ath-Thawrah Dam (its reservoir is Lake Assad) at Tabqa in Syria (Vesiland, 1993). This will have major downstream effects and flow into the Shatt al Arab shared between Iran and Iraq will be greatly decreased, perhaps allowing greater penetration of saline water and restricting migrations of fishes. The discharge regime of the Euphrates River at Hit-Husabia in Iraq for 1937-1973, before construction of large upriver dams, showed a peak in May of 2594 cu m/sec and a low in September at 272 cu m/sec. For the period 1974-1998, the flow had evened out with a range of 575-841 cu m/sec (Partow, 2001). The spring flood waters, essential to the marshes and the significant factor in the reproductive life of the fishes, have been eliminated. Marshes will be reduced in size and may even be eliminated. Salinisation, pollution and sediment load trapped behind dams, will all affect the fish fauna adversely.
Zoogeography
Berg (1940) places this basin in the Mesopotamian Transitional Region, since the boundaries of three zoogeographical regions meet here, namely the Holarctic (i.e. its Palaearctic part), Sino-Indian (= Oriental) and the African (= Ethiopian). The Mesopotamian Transitional Region includes the Tigris and Euphrates basins and the Quwayq River, Syria, forming a single Mesopotamian Province. The province is transitional between the Mediterranean Subregion and the Indian Subregion. Genera such as Leuciscus, Aspius, Chondrostoma, Chalcalburnus and Alburnus point to a Mediterranean or European association while such genera as Glyptothorax, Barilius, Mystus and Mastacembelus point to an Indian association.
Por and Dimentman (1989) regard the Tigris-Euphrates or Mesopotamian basin as a cradle for inland aquatic faunas. A proto-Euphrates collected water from the Levant and had contacts with the Black and Caspian sea drainages before the Pliocene orogeny. Berg (1940) points out that the upper reaches of the Tigris-Euphrates basin today lie on a plateau close to the upper reaches of the Caspian Sea basin. The basin acted as an area where African and Asian species could meet or transit. These connections were interrupted in the early Pliocene by orogeny, rifting and desert formation. Banarescu (1977) and Por and Dimentman (1989) regard the area to be a zoogeographic crossroads with elements from the Palaearctic such as the cyprinid genera Leuciscus and Chondrostoma, Mediterranean genera such as the cyprinid Acanthobrama (although Krupp (1987) refers to this genus as Palaearctic, of Mesopotamian origin), and Oriental genera such as the cyprinid Garra and the spiny eel Mastacembelus.
Khalaji-Pirbalouty and Sari (2004) studied the biogeography of amphipods crustaceans in the central Zagros Mountains. They consider habitat diversification and climatic fluctuations to be the principal factors influencing species diversity and endemism in this area, with the mountains acting as a barrier to species distribution. Endemism is evident in lizards, plants and amphipods as well as fish.
An analysis by Coad (1996b) shows that this basin is mainly Black-Caspian sea basin in its connections, with minor links to Asia and possibly Africa. Numbers of families, genera and species shared between the Tigris-Euphrates and neighbouring basins are summarised in this analysis. Relatively few taxa appear to have made the transition between Asia and Africa or survived subsequent climatic and habitat changes.
Certain families are absent from the Tigris-Euphrates but are found in the Indus and the Nile (Notopteridae, Schilbeidae, Clariidae, Anabantidae, Channidae). These are assumed to be of Gondwanic origin and are separated today by plate tectonic movements. Only two families are shared between the three basins but are not found to the north, Bagridae and Mastacembelidae, and the relationships of the two species in these families are with the Indus (Travers, 1984).
At the generic level, some have dispersed into eastern Iran from the Indus and other eastern basins but have not reached the Tigris-Euphrates basin, presumably for reasons of time or lack of suitable environmental conditions, e.g. Aspidoparia, Crossocheilus, schizothoracines. However two genera have reached the Tigris-Euphrates (Glyptothorax, Barilius) and Howes (1982) considers Cyprinion to be related to the eastern genus Semiplotus. Barilius resembles Indus and other eastern species superficially although its relationships have not been fully worked out. Assuming that these taxa dispersed westward from the Indus and the east, the route must be determined. All but Cyprinion are absent from much of Iran, including the bagrid Mystus and the mastacembelid Mastacembelus referred to at the family level above (Mastacembelus is not found in eastern Iran and hence does not have a continuous range throughout the Orient (pace Travers (1984)). It is unlikely that rivers of the Tigris-Euphrates basin were once tributary to the Indus when sea levels were lower during glaciations as the Gulf of Oman descends to an abyssal plain at 3340 m. I suspect, but cannot prove, that these taxa reached the Tigris-Euphrates basin across the Iranian land mass and subsequently became extinct as desiccation increased. Many of the rivers in southern and eastern Iran today are very small, regularly dry up and some are highly saline. They may be unsuitable for these taxa. Barilius, it should be noted, appears to prefer, in Asia and the Tigris-Euphrates basin, large lowland rivers and its dispersal across Iran is difficult to envisage by headwater capture (the other genera can be found in small streams at higher altitudes as well as lowland rivers). However Berg (1940) suggested that fish dispersal across this region was facilitated by the coastal rivers of Iranian and Pakistani Baluchestan being part of a single river system in the Pliocene, since submerged by subsidence. The presence of Mastacembelus and Barilius in western Iranian basins is attributed to headwater capture and/or colonisation from the Tigris-Euphrates basin when Gulf rivers were tributary to an expanded Tigris-Euphrates basin during lowered sea levels in glacial times. This distribution of these genera is not, therefore, a remnant of the dispersal across Iran from Asia.
At the generic level, only Garra is found from the Indus to the Nile and in the Tigris-Euphrates basin. Menon (1964) suggests that Garra reached the Tigris-Euphrates basin and Africa in two "waves" from Asia, the first wave being in the Miocene to the Tigris-Euphrates basin, the second through southern Arabia to Africa during the Pliocene. Karaman (1971) disputes Menon's Garra waves based on anatomy and zoogeography. Garra presumably dispersed from Asia to Africa via the Tigris-Euphrates basin and the Levant. The apparent continuous distribution of Garra across southern Arabia is not borne out in systematic analyses by Krupp (1983). Garra (and Cyprinion) species of southeastern Arabia are clearly related to southern Iranian species, having crossed the Arabian (= Persian) Gulf when it was drained during the Pleistocene and part of an extended Tigris-Euphrates basin. Southwestern Arabian species (and a Barbus species) are a mixture of African and Levantine elements. Krupp (1983) found no evidence in his studies for the Arabian Peninsula serving as a transition area in an exchange of freshwater fishes between Asia and Africa.
Nemacheilus s.l. (Balitoridae) also has a similar wide distribution but is probably polyphyletic and requires a detailed revision to enable adequate zoogeographical analyses to be made. The systematics of loaches in the Middle East is a contentious subject (Por and Dimentman, 1989). The absence of Balitoridae species from southern Arabia also argues for a dispersal route through the Tigris-Euphrates basin as these cryptic fishes are found today in many small streams throughout Southwest Asia and are unlikely to have been eliminated from southern Arabia through desiccation.
The only Nile (or east African) genus present in the Tigris-Euphrates basin is Barbus. Certain members of this polyphyletic genus in Southwest Asia are characterised by sharing 6 branched anal fin rays, last unbranched dorsal fin ray a smooth spine, large scales, few gill rakers, high dorsal fin ray counts, reduced barbel numbers, compressed body, and other characters which set them apart from European Barbus as a monophyletic group, probably related to east African species (suggested by Banister (1980)). These Barbus species are found from southwestern Arabia (but not southeastern Arabia), through the Levant and the Tigris-Euphrates basin to rivers at the Strait of Hormuz in Iran. They may represent an African element in the fauna of the Tigris-Euphrates and may reflect the route of the cichlid Iranocichla or its ancestor from Africa to the Strait of Hormuz. Bănărescu (1992b) considers African elements in Southwest Asia to be the oldest, of at least Miocene age.
A significant proportion of the families and genera in the Tigris-Euphrates basin is also found in the Black-Caspian sea basin. Such widespread, northern cyprinid genera as Alburnoides, Alburnus, Aspius, Chondrostoma, and Squalius reach their southern limit in the Tigris-Euphrates basin (and neighbouring Iranian basins) suggesting that they reached the Tigris-Euphrates basin from the north.
The presence of Glyptothorax in the Black Sea basin of Anatolia (Coad and Delmastro, 1985) is a recent event through headwater capture from the Tigris-Euphrates basin and thus far is the only example of a clearly-defined Indus genus reaching the Black-Caspian seas basin. It is probably an example, in reverse, of the colonisation of the Tigris-Euphrates basin in recent times from the Black-Caspian seas basin. Headwaters of a number of Tigris-Euphrates basin rivers interdigitate with the upper reaches of Black-Caspian seas basin rivers, e.g. the Aras River of the Caspian Sea and the Kizilirmak of the Black Sea with the Euphrates near Erzerum and Sivas respectively; the Qezel Owzan of the Caspian Sea with Tigris River tributaries. Headwater capture is common in the Zagros Mountains (Oberlander, 1965) and in Anatolia and pluvial conditions in the past would have facilitated fish dispersal. Por and Dimentman (1989) mention direct connections of a proto-Euphrates with Black Sea and Caspian sea fluviatile drainages before the Pliocene orogeny which would serve to allow entry of taxa to the Tigris-Euphrates basin. Direct connections were interrupted by the early Pliocene as orogeny, rifting and desertification took hold. Almaça (1990) has reviewed possible routes for Barbus species into Iran and the Tigris-Euphrates basin from the north via what is now Anatolia and east of the Caspian Sea dating from the early Oligocene. A continuous route for exchange of taxa has been possible since the upper Miocene, almost 12 million years ago. These routes have been variously available down to modern times for Barbus and other taxa as exemplified by some species being in common between the Black-Caspian seas basin while others are distinct but related at the generic level. Bănărescu (1992b) considers that northern or European elements penetrated to the Tigris-Euphrates basin earlier than Asian ones, and that this partially explains their prevalence.
Iranian internal and Gulf basins and the Levant show evident affinities with the Tigris-Euphrates basin. The ichthyogeography of the Levant has been dealt with by Krupp (1987) and will not be reviewed here. Krupp considers that parts of the Levant were colonised separately via branches of the Tigris-Euphrates river system. Iranian basins to the west of the Tigris-Euphrates basin have a very similar fauna to that of the Tigris-Euphrates at the species level. The diversity falls off rapidly with distance (Coad, 1987). Headwater capture in the Zagros Mountains is an evident route for species found in common with the Tigris-Euphrates basin but not in Iranian rivers draining separately to the Gulf. The draining of the Gulf during Pleistocene lowering of sea levels enabled Tigris-Euphrates basin fishes to colonise tributary Iranian rivers now separated by a rise in sea level (Hamblin, 1987). The melting of the Laurentide ice sheet and drainage of Lake Agassiz in Canada caused this rise in sea level world-wide, including the shallow Arabian (= Persian) Gulf (Perkins, 2002). By about 11,500 years B.P., the Gulf was filled with present shorelines attained shortly before 6000 B.P. and exceeded by 1-2 m (Lambeck, 1996).
Por and Dimentman (1989) regard the Mesopotamian subregion or Tigris-Euphrates basin as one of the most isolated major freshwater areas in the world. However, as Coad (1996b) points out, endemism is only at the species level and diversity is low with only about 52 primary division species in 7 families, 34 species of which are Cyprinidae (and fewer species in Iraq itself).
Xenopoulos et al. (2005) present scenarios for freshwater extinctions based on climate change and water withdrawal. The combined effect of these two factors could lead to the loss of 30% of the Tigris River fish species and 54% of the Euphrates River species by the year 2070.
Pollution
Pollution is an ongoing problem in Iraq as with any area heavily dependent of limited water supplies, especially when much of the available water originates from outside the country. The country has also been subject to sanctions and wars in recent decades and this disruption of civil society also contributes to pollution, along with the debris of military action (Al-Azzawi et al., 2001; Al-Daham, 2001; Hussein, 2001).
Pollution from the Gulf War and the burning of the Kuwaiti oil wells must also have affected the marshes and their fishes, as well as much of southern Iraq. Black snow was reported as far away as Kashmir (McKinnon and Vine, 1994). Mercury pollution in fish was below levels considered as background except where fish had eaten treated seed dumped in rivers (levels of 25-30 mg/kg)(Jernelöv, 1976). The United Nations Environment Programme (2003) gives an overview of pollution in Iraq.
The Iran-Iraq War of 1980-1988 severely damaged the Hawr al Hawizah in Iraq, and presumably to some extent in Iran. Bombs and shells, chemical weapons, pollution, burning of reed beds, reed cutting and armoured boats used to smash through obstructing reeds all had deleterious effects (Scott, 1995). The Iraqi shores of this hawr have been drained by dyke construction and river control presumably for military reasons in this border area. Some marsh will survive in Iran because it is fed from wholly Iranian rivers but Iran News (19 February 1995) reports that draining of Iraqi marshes will lead to desertification inside Iran.
Pollution is widespread in the Shatt al Arab from industrial, agricultural and untreated human wastes. Douabul et al. (1987) describe the heavily polluted branches of the Shatt al Arab in Basrah and Mudeer and Hassan (1999) describe chemical pre-precipitation to reduce phosphate from sewage. Hussain et al. (2001) evaluate environmental degradation in the Iraqi portion of the Shatt al Arab and its effects on the fish fauna. Domestic sewage was a problem at one site while agricultural drainage affected another site adversely. They also noted that commercial and recreational fishing of Barbus kersin, B. xanthopterus, B. grypus, B. sharpeyi, Cyprinus carpio, Silurus triostegus and Aspius vorax contributed to poor recruitment. Yousif et al. (2000) found that organic sewage released by the city of Basrah lowered diversity and increased the numbers of dominant species in parts of the Shatt al Arab. Al-Saad and Al-Asadi (1989) record petroleum hydrocarbons from seven fish species in the Shatt al Arab, although levels indicated no direct danger to human health. Petroleum hydrocarbons are generally present in southern Iraqi rivers due to industrial processes and waste from loading ships (Al-Timari et al., 2003). Al-Saad et al. (1997; 1997; 1998) recorded levels of polycyclic aromatic hydrocarbons in the Shatt al Arab estuary and in some fishes from the 1991 oil spill and found them to be relatively low, reflecting their hydrophobic nature, the complexities of the estuarine system and fish avoidance of oil spills. The levels did not present a hazard to human health. High nutrient levels were attributed to agricultural activities in 1979/80 and 1991/92 while in 1997/98 an increase in phosphate was thought to be due to pesticides or sewage waste (Mahdi et al., 2002).
Rahim et al. (1973) describe the effects of tannery wastes containing sulphur compounds near Mosul which were the apparent cause of a fish kill through reduction in dissolved oxygen. A proteolytic enzyme, papain, was also involved. Mahmoud and Ahmad (1979) showed the Tigris to be polluted near Mosul from raw wastewater discharge. Mutlak et al. (1980; 1980) demonstrated bacterial and salinity pollution in the Tigris at Baghdad and Zahid (1980) faecal pollution in the Army Canal at Baghdad and in the Diyala River. Khayat et al. (1986) document fish kills at Mosul from dairy and brewery water discharges causing a sudden drop in dissolved oxygen levels. Al-Daham et al. (1981) reviews industrial pollution problems in inland waters of Iraq and their effects on fishes. Fishes like Tenualosa ilisha, Barbus grypus and B. xanthopterus from the Shatt al Arab, for example, frequently carried an odour of oil or of kerosene when cooked. Latif et al. (1982) found bioaccumulation of copper, cadmium, lead and zinc in Barbus belayewi (= Capoeta damascina) and Barbus grypus in the Diyala River at Rustemyia, an area where municipal and industrial sewage is thrown into the river. Almukhtar et al. (1985) described variations in physico-chemical parameters of the Tigris and Diyala rivers near Baghdad and the effect of domestic and industrial wastes. Almukhtar et al. (1986) found severe depletion of oxygen in the Diyala River in summer downstream of a wastewater treatment plant although Barbus grypus, Chondrostoma regium and Heteropneustes fossilis thrived. Al-Omar et al. (1986) investigated the presence of organochlorine insecticides (formerly used in malaria control) in 11 species of fish from the Diyala River and high levels were found. Khalaf et al. (1986) studied heavy metal levels from sewage wastes in specimens of Barbus belayewi (= Capoeta damascina) from the Diyala River and found significant levels and bioaccumulation. Al-Ani et al. (1987) found the water quality in the Al-Jaysh Canal at Baghdad, used for irrigation but also supporting a fish fauna, to decline with reduction in flow rate, consequent demands in summer and a high rate of oxygen depletion. DouAbul et al. (1987) describe organochlorine pesticides in fish from the Shatt al Arab and Hawr Al Hammar, with higher levels of dieldrin in Tenualosa ilisha, a migratory species, which may have been exposed elsewhere. Abaychi and Al-Saad (1988) studied concentrations of trace elements in sediments and a wide range of commercial fish species from the Shatt al Arab and Khawr az Zubayr. Concentrations were lower than at heavily polluted sites but there was no correlation with feeding habits. Al-Omar et al. (1989) investigated organochlorine residues in Diyala River water from a sewage treatment plant. Al-Muddafar et al. (1990) studied hydrocarbons in surface sediments and bivalves from the lower Tigris and Euphrates rivers and in the Shatt al Arab and found them to be relatively unpolluted, the sources being mostly sewage discharge and urban run-off but also dust fallout. Mohammed (1990) covers the failed attempt to revive the Khair River, a polluted stream in Baghdad, by diverting clean water from the Tigris River. Barak (1995) records zinc and copper concentrations higher than baseline in Aphanius dispar and Gambusia holbrooki from the Shatt al Arab and Hawr al Hammar. Al-Imarah et al. (1996) studied industrial waste in the Diwaniyah River and found, for example, higher values of SO4-1 from a rubber factory. The levels of trace metals in the southern part of the artificial Saddam River (see above) were higher than in the Shatt al Arab (Al-Shaway, 1998). Al-Imarah (2001) showed that the Shatt al Arab was polluted with PHCs and trace metals and these were found in fish muscle samples. Al-Timari (2001) reviewed oil pollution levels in southern Iraq and the Arabian (= Persian) Gulf and Hantoush et al. (2001) petroleum hydrocarbon levels in fish; a high concentration (12.55 µg.g-1) was noted in Liza subviridis in autumn for example. Jassim and Hameed (2001) reported on the thermal and chemical effluent from the Najibia power station in Basrah. Al-Maliki (2001) reported on ammonia levels in branches off the Shatt al Arab where maximum levels were reached in summer through decay of organic and inorganic compounds at higher temperatures. Ghliem (2001) measured NO3- levels in Iraqi waters in 1994 and found major increases at some localities compared to 1970 (3020% at Samarra for example).
After the occupation by British soldiers, the use of nets attached to car batteries to electroshock fish within a 5 m radius became prevalent in the marshes. This yielded, exceptionally, 20 kg of fish per fisherman each day but also killed species not marketable and left their bodies to rot, such as jirri (Silurus triostegus). Poisons were used to catch birds and farmers used chemicals intended to treat lice in sheep as crop pesticides, polluting the marshes (www.taipeitimes.com, downloaded 19 September 2005). Pesticides have also been used to catch fish in the marshes.
History
A theory has been advanced that the silt-laden discharge of the Tigris-Euphrates-Karun rivers has built out a delta into the Arabian (= Persian) Gulf. The head of the Gulf would have reached Baghdad and Samarra about 7000-6000 B.P. and since then the land area is supposed to have extended some 200 km southward. The present plains would not then have been as extensive and rivers from Iran would have entered directly into the Gulf. The Admiralty Naval Staff (1918), Mason et al. (1944), Adams (1962), Hansman (1978), Maltby (1994), Lambeck (1996) and Karim (1998) provided illustrations of this recession of the head of the Arabian (= Persian) Gulf in historic times along with details of historical and archaeological evidence. The sea coast was then supposedly as far inland as Amara and Nasiriyah and Ahvaz in Iran for example. Lees and Falcon (1952) proposed that in fact downwarping occurs under the weight of sediment. Certainly the silt load has not built up a land surface. The coastline, under this theory as interpreted by Fisher (1968), has been constant since the end of the Pliocene and presumably as a marsh habitat for fishes too. However Lees and Falcon did state that there were advances and retreats through historic and prehistoric time. Voûte and Wedman (1963) also opt for small oscillations in the shoreline. Ionides (1954), Larsen (1975) and Nützel (1975) refuted Lees and Falcon and maintained that marine clays and silts indicate a marine embayment as far inland as Amara in Iraq (31°50'N, 47°09'E) and that the third millennium cities of Ur and Eridu have left cuneiform sources placing them on the sea although now they are 100 km from the head of the Arabian (= Persian) Gulf. Lees and Falcon did not take into account sea level changes such as the postglacial rise of 100 m and interglacial rises of 30-100 m. Active growth of a delta at the head of the Gulf over the last 20,000 years may only have occurred from 10,000 to 2000 B.P. and again in the last 300 years. Subsidence levels are probably not as great as postulated (Vita-Finzi, 1978). Nevertheless, there were probably marshes to the north and they may have just become more available and extensive in recent centuries (Aqrawi, 2001). As Larsen and Evans (1978) and Wagstaff (1985) point out, the Arabian (= Persian) Gulf shoreline at the head of the Gulf has been affected by, and rendered difficult to interpret by, a complex of factors including confusion of marine and freshwater fossils in an estuarine environment, subsidence, eustatic sea level fluctuations, local seismic activity, climate and therefore hydrologic changes, and cultural changes such as irrigation.
Diester-Haass (1973), based grain size and pteropod distributions in the Arabian (= Persian) Gulf, and the summary of Nutzel (1976) record an arid period about 9000 B.P., succeeded by a more humid period, then a period of less rainfall and then, in the late Holocene, by an increase in rainfall. Laessøe (1951) describe irrigation systems from the eighth century B.C. Jacobsen (1960) detailed some of the changes in the courses of rivers and canals, based on evidence of ancient settlements which were presumed to be linearly arranged along water courses. Voûte and Wedman (1963) detail how the Quaternary climate changed the discharge of rivers and even how landslides created lakes. Mallowan (1964) also maps some ancient river courses. Weiss et al. (1993) document collapse of a third millennium north Mesopotamian civilisation which demonstrates that desertification and changes in human impact on the environment are not solely recent events. Butzer (1957, 1958a, 1958b, 1961, 1975, 1978), Wright (1977, 1983) and Roberts and Wright (1993) review environmental and climatic change in this area of the Middle East and Lamb (1977, 1982), Nasrallah and Balling (1993), Neumann (1993) and Neumann and Sigrist (1978) also review climate change. The fish fauna has evidently had to cope with a changing availability of habitat and varying human pressures through the post-glacial period. Floods and changes in river courses over this time have no doubt facilitated movement of fishes between the Tigris and Euphrates rivers and the various marshes.
Between 20 and 15 thousand years ago, the Arabian (= Persian) Gulf was dry as water was locked up in ice-caps and sea level was 110-120 m lower than today (Sarnthein, 1972; Kassler, 1973; Nützel, 1975; Al-Asfour, 1978; Al-Sayari and Zötl, 1978; Vita-Finzi, 1978; Hamblin, 1987; Karim, 1998). The floor of the Gulf was then thought to be a generally waterless, flat depression with a few swampy tracts rather than a "Garden of Eden" as has been proposed. A marine transgression occurred between 12 to 8 thousand years ago and by 6 thousand years ago the present sea-level was attained. Streams now isolated from the Tigris River basin by the sea in the Gulf and Hormozgan basins of Iran would have been tributary to an extended Shatt al Arab, extending 800 km down the gulf to form an estuary at the shelf margin in the Sea of Oman, now under 110 m of sea. Earlier regressions no doubt occurred and facilitated the movement of fishes.
Etymology
There are various words in Arabic which describe aquatic, fish-related or geographical features and may be found on maps or in the literature, e.g. the important marshes in Iraq, which figure significantly in reports of fish biology, are called hawr. Most older literature in English has this word spelled hor; and the same applies to khawr and khor. Generally I have followed the U.S. Board on Geographic Names for Iraq as this includes latitudes and longitudes for localities. In some cases where names are quite variable in spelling the literature, on maps and in gazetteers, I have added the chief variant in parentheses, e.g. Al Kaba'ish (Chabaish); note that even this may appear as Chebaish and other variants.
Terms include (simplified without diacritical marks):-
ab = water, intermittent stream, stream, spring, lake, well, wadi (Persian)
abar = wells
al-ahwar = the southern marshes (plural of hawr or hor)
al-shiah = construction of mud dams to isolate fish
al-suwaise - burning a reed island to scare fish into a net
al-tawamees = fishing by diving and seizing fish by hand
al-zahar = fishing with poison (see below under Fisheries for description)
atta = ground corn with the husks unsifted, in a paste used as bait for large Barbus esocinus
av = stream (Kurdish)
`ayn = spring
badiyat = desert
bagh = garden (Persian)
bahr = sea, lake
bahrat = wadi
balam = a heavy, double-ended boat used for netting fish in the southern marshes
bid'at = canal, stream
bilid = a line with 3-4 hooks, baited with meat
bi'r = well
birkat = pool, well, marsh, lake
buhayrat = lake
cay - stream (Turkish)
cham = stream (Kurdish)
çay = stream (Turkish)
chay = stream
chiha = a dip-net (see below under Fisheries for description)
dag = mountain, hill (Turkish)
dagh = mountain, hill
darrah = stream
dere = stream (Turkish)
dissid = crossbow net (see below under Fisheries for description)
elwet al-samak = fish market
falah = a five-pronged spear once used to catch fish in the southern marshes
faydat = salt flat, depression
felleh = falah
galal = stream
garfa = a seine (see below under Fisheries for description)
gargoor = a fish pot made of wire mesh used in marine waters
ghadir = waterhole
ghazl = a gill net with large holes, allowing young to escape
göl = lake, marsh, swamp (Turkish)
gölü = lake, marsh, swamp (Turkish)
hadafi = cast net (see below under Fisheries for description)
hadra = a set-trap or fixed stake net used in the Shatt al Arab and the Gulf with one wall (70 m long) at right angles to the current and the trap chamber at the outer end. Hadra is Arabic for enclosure
hawr = marsh, lake
hedash = an illegal gill net with 11 mesh holes per foot (from the Arabic for eleven, heda'ash), cf. suba'e
hiyala = a drift net (see below under Fisheries for description)
hor = marsh, lake (= hawr)
howr = marsh (Persian)
jabal = mountain, hill, range
jadwal = stream, canal
jazirat = island
jebal = mountain, hill (Persian)
jibal = mountain, hill
kandi = stream (Persian)
kani = stream
kelan = a fish trap (see below under Fisheries for description)
kerkur = a small round trap made of reeds
khabari = marshes
khabrat = mud flat, spring, rain pool
khawr = channel, tidal inlet, marsh, wadi
khirr(ah) = stream
khor = channel, tidal inlet, marsh, wadi (= khawr)
kuh = mountain, range, hill, peak, ridge, spur (Persian)
liwa = province
maddih = longline (see below under Fisheries for description)
mailan = a set trap used on the sea shore and along the Shatt al Arab to catch such species as Tenualosa ilisha (sbour). Roughly v-shaped with the opening towards the shore, the trap catches fish by permitting them to enter near the shore and trapping them as the tide falls. The trap was traditionally made of date palm leaves. The trap wings are about 400 m long and the trap heart diameter is about 2.5 m. Small trapped fish are scooped out and large ones speared.
makhraj = canal
mamarr = pass
maqam = tomb, shrine
masgouf = mazgouf
mashuf = the small canoe of the southern marshes
matihaf = museum
mazar - shrine
masgouf = an Iraqi delicacy, particularly in Baghdad, where a member of the carp family (Cyprinidae) is degutted, split, salted and woven onto stakes over an open fire for roasting
mina' = port
mudhif = guesthouse of the southern marshes
nahr = stream, canal
nehri = stream (Turkish)
odda = a stake net used to catch sbour (Tenualosa ilisha) in the Shatt al Arab. The tidal current pushes out the net supported on poles into a bag shape where fish are trapped or gill-netted
qada = administrative district
qal`at = fort
qalb = hill
qarat = hill, cairn
qasr = fort
qulban = wells
qur = hills
quwayrat = hill, mountain
ra's = hill
rijlat = stream, wadi
rubar = stream (Kurdish)
rud = stream, river, intermittent stream (Persian)
rudkhaneh = stream, river, river bed, watercourse, intermittent stream (Persian)
rujm = cairn, hill
sabil = spring, stream
sabkhat = salt marsh, lake
sahra = desert
samak = fish
sha'ib = wadi, stream
shas = a line with one hook
shatt = stream, distributory, large river, bank of a river
sh`ib = wadi
shu`ayb = stream, wadi
silliya = cast net (see below under Fisheries for details)
silliye = silliya
sissi = drag-net (see below under Fisheries for description)
su = stream (Turkish)
suba'e = a legal gill net with seven (suba'a) mesh holes to the foot, cf. hedash
suyu = stream (Turkish)
tabr = canal
tahar = a line with ten hooks, baited with meat
tall = hill, mound
tappah = hill
tappeh = hill (Persian)
taruf = dip-net (see below under Fisheries for description)
tayar = gill net (see below under Fisheries for description)
tell = hill, mound
tepe = hill (Turkish)
tulul = hills
`uqlat = well(s), rain pool
vilayet = province
wadi = wadi, stream (a wadi, plural widyan in Arabic but usually wadis in English, is a valley formed by water and having seasonal or interrupted water flow)
zara = schooling, but used to denote the reproductive migration of carp family members into the marshes in spring
And finally, the name of the gulf lying between Iran and the Arabian Peninsula is either the Persian Gulf or the Arabian Gulf, depending on which shore you stand. In deference to colleagues from both shores, I have used Arabian (= Persian) Gulf, which should satisfy no one.
Written records extend back to the third millennium
B.C. in Mesopotamia, the plain shared between Iraq and Iran.
A copper and
bronze fishhook from Mesopotamia has been dated to 3500 B.C. (Caddy and
Cochrane, 2001). The Uruk IV symbol
for fish dates to 3100 B.C. or 5050 B.P. Later cuneiform writing on clay tablets,
pottery, cylinder seals, reliefs
and sculptures refer to or illustrate fishes and fishing and attempts have been made to identify the species, with
variable results, and their cultural significance (Löw, 1906; Holma, 1912; Patterson, 1915;
Scheil, 1918; Diemel, 1926a, b; van Buren, 1939; Civil, 1961: Landsberger, 1962;
Salonen, 1970; Dandamaev, 1981; Green, 1986; Sahrhage and Lundbeck, 1992; Seidl,
2006). About 324 Sumerian and Babylonian
fish names have been identified
referring to about 90 species (some of which are
marine). A fish hook from Jemdat Nasr is at least 5000 years old
(www.ashmol.ox.ac.uk, downloaded 19 September 2005).
Even a wind vane was in the shape of a fish, perhaps a shark or a mythological water creature (Neumann and Parpola,
1983). Fish played a prominent part in every day life, both as food and as
religious symbols, and fish oil was used in ointments (van Buren, 1948; Salonen, 1970; de Moor, 1998;
Lev, 2006).
A fermented sauce called siqqu was made from fish, shellfish and
grasshoppers and was used in the kitchen and at the table (Lawton, 1988).
Fishing regulations had set penalties and fishing rights were leased. Guilds of fishermen existed and transport to cities with marketing was organised. Fishermen were divided into freshwater fishers, sea fishers and fishers in salt water, the latter working in tidal lagoons and the delta of the Tigris and Euphrates. Fish were sun-dried, salted, pickled, fermented and possibly smoked. Fishermen had to deliver part of their catch to the temples or as duties. Surplus fish were sold to the public. Consumption of fish was prohibited on certain days Fish ponds were used to keep a food supply alive (Sahrhage and Lundbeck, 1992; Bottero, 1985; 2004).
The Babylonian Epic of Creation mentions nets and splitting fish for drying. Amulets and cylinder seals depicting fish are common. A hymn which praises Ishtar of Uruk gives the result of her favour as "whole channels are filled with fish, the channels swarm with fish and with dates". Fish were offered as sacrifices to gods and as part of funeral rites, as symbols of life and its renewal, and of fertility (Wright, 1990). The amount of fish required was clearly stipulated and whether it should be fresh, roasted or dried. The commoner species were requested by the basketful but rarer species were requested by numbers so a practical knowledge of diversity existed in the distant past. So numerous were sacrificial offerings that at Uruk I the floor of a room or court was covered with a thick layer of fish scales and fatty waste that gave it a deep golden-yellow tinge. Some areas had layers of compacted fish, 4-5 cm thick, comprising skeletons, skin and scales, indicative that these were not kitchen wastes but were sacrifices (van Buren, 1948). An Assyrian king would have 10,000 fish served at a banquet, although these were cheaper food items and the Sumerians favoured large, plant-eating carps from muddy pond bottoms (de Moor, 1998).
Archaeological remains containing fish bones at Abu Salabikh, Iraq, dated to 3000 B.C. have been identified to include Barbus esocinus, B. grypus, B. kersin, B. luteus, B. sharpeyi, B. xanthopterus, Aspius vorax, Acanthobrama (presumably A. marmid), Cyprinion sp., Alburnus sp., Silurus triostegus, Mystus pelusius, Mastacembelus mastacembelus, Liza abu, Acanthopagrus sp., and Tenualosa ilisha (von den Driesch, 1986; Sahrhage, 1999).
Field (1932) found fish hooks and stone weights, presumed to be for nets, at Jemdet Nasr and Kish from about 3500 B.C. and found fish remains at Kish that were from the third millennium and attributed to a flood stratum (Field, 1936).
Radcliffe (1926), Salonen (1970) and Sahrhage and Lundbeck (1992) review fishing in Assyrian and Sumerian-Akkadian times using nets, spears, traps, weirs, and copper hooks and line, sometimes fished from boats. Contracts concerned with fish ponds date from the reign of Darius II, in 422 B.C., and with fishing in 419 B.C. He also discusses Ea, the god of water dating back to Sumerian times, for which a fish-god or man-fish was a symbol, still to be seen on ancient monuments (see also Green (1986))
The Arabic work Aja'ibu-l-Makhluqat or "Wonders of Creation" by Zakariya b. Muhammad b. Mahmud al-Kammuni al-Qazwini published in 1263 A.D. and later translated into Persian and enlarged in 1275, records sharks entering rivers at the head of the Arabian (= Persian) Gulf to Basrah on the Tigris and comments on their ferocity and their teeth like points of spears, swords or saws. Other Arabic and Persian works contain few recognisable species of freshwater fishes although the tenth century Kitab al-Tabikh from Baghdad contains some fish names such as bunni (= probably Barbus sharpeyi) and shabbût (= probably Barbus grypus) (Perry, 1998). The Kitab al-Tabikh also points out that best fish to eat are river fish, particularly those from cold, stony rivers with the first quality fish being from the Tigris and the second from the Euphrates. Various recipes are given including fish skin stuffed with fish forcemeat, a fish drowned in grape juice to give its flesh a savour, and a fish cooked in a clay oven with its head free, the middle of the body wrapped in cloth and the tail in coarse cloth soaked in oil to give a fish with a roasted head, baked middle and fried tail. Probably the best example of an early "scientific" Islamic work on zoology is the fourteenth century "Nuzhatu-l-Qulub" or "Hearts Delight" by Hamdullah Al-Mustaufi Al-Qazwini (translated into English by Stephenson (1928)). Only the "tarikh" is identifiable as a freshwater fish - Chalcalburnus tarichi from Lake Van in modern Turkey.
A general survey of natural history studies in the Muslim world is given by Mirza (1983), an Islamic approach to the environmental crisis by Zaidi (1981), and Islamic principles for conservation by Ba Kader et al. (1983).
Scientific works relevant to Iraq begin with the Systema Naturae, 10th edition, by Carolus Linnaeus (1701-1778) published in 1758 and in which scientific naming in zoology has its beginning. Linnaeus adopted many of the names from the system developed by Petrus Artedi (1705-1735) who, on a visit to Amsterdam to examine a collection of fishes from the East and West Indies, drowned in one of the canals. Genera subsequently found in Iraq include Cobitis and various species were described in these and other genera. After this date a variety of papers were published by authors in many countries describing fishes scientifically and some of these fishes were eventually found to occur in Iraq as with the Linnaean genera and species. Examples include Marc Elieser Bloch (1723-1799), a physician who began to devote himself to ichthyology at the age of 56, and Johann Gottlob Schneider (1750-1822) who collaborated with Bloch and published their "Systema Ichthyologiae" in 1801 after Bloch's death. This work contains all known species at that time (Bloch also wrote "Naturgeschichte der ausländischen Fische, 1785-1795) and in these works appear such Iraqi species as diverse as the riffle minnow, Alburnoides bipunctatus and the Indian stinging catfish, Heteropneustes fossilis (see Karrer et al., 1994); and Johannes Müller (1801-1858) and Friedrich Gustav Jacob Henle (1807-1885) who published their "Systematische Beschreibung der Plagiostomen" in 1838-1841, the classical work on sharks and their relatives
? (see Kähsbauer, 1959; Adler, 1989; Herzig-Straschil, 1997.
Fish descriptions from the Middle East begin with the work of Fredrik Hasselquist (1722-1752) in his "Iter Palaestinum eller Resa til Heliga Landet Förrättad ifrån År 1749 till 1752" or "Voyage to the Holy Land Undertaken from the Year 1749 to 1752" which was published by Linnaeus in 1757 after Hasselquist "Succumbed to the fatigues and cares of the Journey" (Günther, 1869). Although this work appeared before Linnaeus' 10th Edition and is thus rejected as far as scientific nomenclature goes, it still contains recognisable and scientific descriptions of fishes.
Alexander Russell, physician to the British Factory at Aleppo from 1742?-1753, gave an account of four undescribed fishes from modern Syria in 1756 (see Russell (1794) for greater detail and illustrations) of which Mystus pelusius and Mastacembelus mastacembelus were later found in Iraq. The descriptions in this work are attributed to Daniel Carl Solander (1736-1782) and to Sir Joseph Banks (1743-1820) and Solander respectively (Wheeler, 1958). Since then a number of works have appeared on Middle East fishes and although many were restricted to Syria, the Jordan River basin or drainages of Anatolian Turkey they often contain descriptions of species also found in Iraq.
Several authors worked on marine fishes in the Indian Ocean and Red Sea, describing species eventually found to penetrate or live in fresh waters of southern Iraq. First among these was Petrus Forsskål (1732-1763), a Swedish member of a Danish expedition to the Red Sea in 1762 (Nielsen, 1993). Forsskål and four of his companions died and it was left to the sole survivor, Carsten Niebuhr (1783-1815), to publish Forsskål's fish descriptions posthumously in 1775. Some of Forsskål's specimens survive as dried skins in the Zoological Museum of Copenhagen. Wilhelm Peter Eduard Simon Rüppell (1794-1884) of the Senckenberg Museum, Frankfurt collected fishes in the Red Sea in 1822 and published "Fische des rothen Meeres" in his "Atlas zu der Reise im nördlichen Afrika" (1828-1830) followed by further field work in 1831 resulting in a second "Fische des rothen Meeres" in Neue Wirbelthiere zu der Fauna von Abyssinien gehörig (1835-1838). Rüppell described the tooth-carp Lebias dispar (= Aphanius dispar) now found in southern Iraq. Later works are summarised by Dor (1984) and Dor and Goren (1994) for the Red Sea. The Arabian (= Persian) Gulf fishes have received attention although there has been no comprehensive review of the fauna and its literature. Some principal works on this marine fauna include Blegvad and Loppenthin (1944), White and Barwani (1971), Randall et al. (1978), Relyea (1981), Sivasubramanian and Ibrahim (1982), Fischer and Bianchi (1984), Al-Baharna (1986), Kuronuma and Abe (1986), Asadi and Dehqani Posterudi (1996), and A'lam (1999a).
However the most important early work on the Middle East and specifically on Iraq is that of Johann Jakob Heckel (1790-1857), Inspector at the Imperial Royal Court Collection of Natural History in Vienna. He described the collections sent by Theodor Kotschy (1813-1866) to Vienna from "Syria" which includes such places as the Quwayq (= Coic, Kueik or Kuweiq) and Orontes rivers near Aleppo and Antioch, Damascus, the Jordan River, Mosul on the Tigris River and Kurdistan (Herzig-Straschil, 1997). In addition, collections were made in Iran from around Shiraz. Note that measurements used by Heckel are the "Wiener Zoll" = 26.34 mm comprising 12 "Linien" (= 2.195 mm) as opposed to the English inch (= 25.40 mm) from information courtesy of Dr. Barbara Herzig, Naturhistorisches Museum Wien. Heckel's descriptions appeared in Joseph Russegger's "Reisen in Europa, Asien und Afrika" in 1843 (volume 1, part 2) for the "Süsswasser-Fische Syriens" continued in 1846-1849 as a "Naturhistorischer Anhang" followed by "Die Fische Persiens gesammelt von Theodor Kotschy" (both in volume 2, part 3). The Syrian collections contained a number of species later found in Iraq. In total 70 species were described or mentioned from "Syria" and many of the specimens are still to be found in excellent condition in the Naturhistorisches Museum, Wien. Note that these collections contained numerous specimens (and still do) while the catalogue in Vienna lists relatively few, presumably those which Heckel intended to be the type series. Heckel's publications often do not give accurate counts of the specimens on which the species is founded. It is not always evident which specimens are types and the whole series from a type locality is regarded as syntypes.
The dating of Heckel's works is not clear for the "Naturhistorischer Anhang" and the "Die Fische Persiens..." parts which have 1846-1849 on the cover. According to the International Code of Zoological Nomenclature the final date is the correct one if it cannot be demonstrated that parts of the work have their own dates. The copies of Heckel's works seen (mostly xeroxes) do not seem to have individually dated parts or sections and so 1849 is used for the date whereas many earlier authors have used 1846. This does not have any significant taxonomic complications as there are no other works with potential synonyms in this date range.
It may be worth noting that Heckel (1843b:995) reports that the collector Theodor Kotschy "did not find trout....in the mountains of Kurdistan. Since we know our collector's diligence, we doubt that trout occurs there" but in (1846-1849a:254) Heckel states "we must add one trout (Salmo), which tastes excellently according to the report presented by our traveler; that trout occurs relatively frequently in the mountains of Kurdistan, but has not been seen by us". This is merely confusing: did Kotschy later find trout or change his account, or did Heckel recall Kotschy's accounts incorrectly? The situation is now compromised by introductions of brown trout (Salmo trutta) into the Zagros Mountains of Iran (see Freshwater Fishes of Iran in www.briancoad.com). Native trout do occur in the upper reaches of the Tigris River but outside Iraqi waters as far as is known, e.g. in the Catak Cay of Turkey (Sušnik et al., 2005).
Of 89 species described from Syria, Iraq and Iran, 72 were described as new species by Heckel, although all are not now recognised as valid. Some of these species, described from other countries, have since been found in Iraq. Heckel's 26 new species from Iraq, all from the Tigris near Mosul save one, may be summarised as follows in order of description with their original names and current designation. Sixteen are considered valid. Some are first mentioned in a footnote with a more detailed description later:-
1. Barbus grypus
2. Labeobarbus kotschyi (= Barbus grypus)
3. Luciobarbus xanthopterus (Barbus xanthopterus)
4. Luciobarbus esocinus (= Barbus esocinus)
5. Scaphiodon trutta (= Capoeta trutta)
6. Luciobarbus shejch (= Barbus pectoralis)
7. Scaphiodon umbla (= Capoeta damascina)
8. Systomus luteus (= Barbus luteus)
9. Systomus albus (= Barbus luteus)
10. Cyprinion macrostomus (= Cyprinion macrostomum)
11. Cyprinion kais
12. Cyprinion cypris (= Cyprinion kais)
13. Discognathus variabilis (= Garra variabilis)
14. Discognathus obtusus (= Garra rufa)
15. Acanthobrama arrhada (= Acanthobrama marmid)
16. Chondrochilus regius (= Chondrostoma regium)
17. Squalius lepidus
18. Aspius vorax
19. Alburnus mossulensis
20. Alburnus capito (mountain streams of Kurdistan) (= Alburnus mossulensis)
21. Cobitis frenata (= Barbatula frenata)
22. Lebias mento (= Aphanius mento)
23. Lebias cypris ( = Aphanius mento)
24. Silurus triostegus
25. Mugil abu (= Liza abu)
26. Cyprinion neglectus (= Cyprinion macrostomum)
Some of this material was sent on exchange or as gifts to other museums although it is not always clear in their records whether the material comprises types, e.g. the Muséum national d'Histoire naturelle, Paris contains specimens marked from Vienna or Heckel of Chondrostoma regium from Mosul (1635), Cyprinion kais from Mosul (1641), Garra rufa obtusa from the Tigris (1633), and Leuciscus lepidus from Mosul (1636). The Museum für Naturkunde, Universität Humboldt, Berlin (ZMB) has some Heckel types listed as such, plus additional material marked as from the Wiener Museum with type localities such as Aleppo and Mosul but without dates. Some of these may also be part of Heckel's material but are not indicated as types in the catalogue. All this additional material has not been investigated in detail by me.
At the time Heckel's descriptions came out a series of 22 volumes was being published in Paris covering all the fishes then known. This work by Baron Georges Léopold Chrétien Frédéric Dagobert Cuvier (1769-1832) and Achille Valenciennes (1794-1865) appeared from 1828 to 1849 and was a seminal work in ichthyology, the "Histoire naturelle des poissons" (see Bauchot et al. (1990) for more details). It contained new species and summaries of descriptions by other authors for a total of over 4500 fishes, including some now known from Iraq or introduced there (3 native species, see Checklists).
A similar work was undertaken by Albert Carl Ludwig Gotthilf Günther (1830-1914) whose "Catalogue of the Fishes of the British Museum" in 8 volumes appeared from 1859 to 1870 and contained new descriptions and reviews of earlier works with over 6840 species described and over 1680 doubtful species mentioned. New species from Iraq or later found there were B. sharpeyi? Barbus subquincunciatus and Hemigarra elegans. Günther also founded the Zoological Record, an annual index of the zoological literature. Günther also described collections and new species from Iraq presented to the Natural History Museum (formerly the British Museum (Natural History)), London. The earliest of these was the collection made by William Henry Colvill at Baghdad which Günther referred to 9 extant species in 1874, including a freshwater shark, and 2 new species, Barbus sharpeyi and Macrones colvillii (= Mystus pelusius). Barbus faoensis (= B. sharpeyi) was described from Fao (= Al Faw) in another paper in 1896.
Henri Emile Sauvage (1844-?) described in 1882 and 1884 the fishes collected by Ernest Chantre of the Lyon Museum on a scientific expedition to Syria, upper Mesopotamia, Kurdistan and the Caucasus including Silurus chantrei (= S. triostegus ?) from the Kura River of the Caspian Sea basin (but Berg (1948-1949) suggests that this species was collected in Syria or the Tigris basin but without any explanation), and Labeobarbus euphrati from the Euphrates River (= B. esocinus).
Viktor Pietschmann (1881-1956), originally Steindachner's assistant and later (1919-1946) in charge of the fish collection at the Naturhistorisches Museum Wien, described Mugil pseudotelestes (= Liza abu) and Glyptothorax steindachneri (identification uncertain) from the Tigris River basin in Iraq based on materials collected on the Mesopotamian Expedition in 1910 (Kähsbauer, 1957).
Lev Semenovich Berg (1876-1950) was a leading Soviet physical geographer and biologist. From 1930 until his death, he was head of the "Special Laboratory of Ichthyology" of the Zoological Institute of the Academy of Sciences of the U.S.S.R. in Leningrad and an Academician (Oliva, 1977). His contributions to the ichthyology of the former U.S.S.R. and to that of Iran appeared in a number of shorter articles and in lengthy monographs from the late nineteenth century onwards. The shorter works are listed in the Bibliography and include descriptions of such new species now known from Iraq as Barilius mesopotamicus and Glyptothorax kurdistanicus. His summary work "Freshwater Fishes of the U.S.S.R. and adjacent countries" was published in 1948-1949 and in English translation in 1962-1965 and has some work of relevance to Iraq, although the taxonomy is now dated. His 1940 work on the "Zoogeography of freshwater fish of the Near East" placed that fauna in context and included Iraq but it was his 1949 work "Freshwater Fishes of Iran and adjacent countries" which has been the major modern work on Iranian fishes with relevance to Iraq. This was based on collections deposited in the U.S.S.R. Academy of Sciences Zoological Institute in Leningrad (acronym ZIL, now St. Petersburg, Russia with the acronym ZISP). The collections had been made by two Russian biologists. The first of these was Nikolai Alekseevich Zarudnyi (1859-1919), a zoologist and ornithologist who made four journeys to Iran for which he was awarded medals and the Przheval'skii Prize by the Russian Geographical Society. His last journey (1903-1904) was to Gorgan, western Khorasan, western Kuhistan, southern Irak-Ajemi and Khuzestan. Zarudnyi's material had previously been examined and described by Nikol'skii (see above). The second biologist was P. V. Nestorov who worked with the Turko-Persian Demarcation Commission in 1914 and collected fishes in the Tigris basin along the present Iran-Iraq frontier.
? general authors of relevance Almaca on Barbus; FAO reports Andersskog, Surber, VDV etc; theses on Iran Armantrout, Saadati, Rostami, Wossughi; summaries Kahsbauer; on specific groups Banarescu on balitorids and cobitids; Karaman on various cyprinids; ditto Howes; Villwock on Aphanius; fisheries studies such as Nevraeav, Kozhin, Derzhavin ? etc; minor collections such as Holly, Fowler and Steinitz, Roux, Spillman, Svetovidov, Pietschmann, Boulenger, Tortonese etc; popular works Barimani, Farid-Pak, Rostami and now Abzeeyan; cave fish Bruun and Kaiser, Greenwood, Smith, Thines; Hunt on sharks; ?
1950-1969; 1970 to present ?
.
Several general works on zoogeography of fishes have encompassed Iraq as part of their study. These include Berg (1933b; 1940), Banarescu (1960; 1977; 1992b) and Por and Dimentman (1989). Most of Iraq is part of the West Asian area, which includes southern Anatolia, the Levant, and the Arabian Peninsula, or an Iranian Province which excludes the Caspian Sea, Lake Orumiyeh and Arabian (= Persian) Gulf and Sea of Oman drainages. Berg (1940) lists the following districts within the ?Iranian Province: The fauna is a mixture of elements from the European (western Palaearctic), the Mediterranean, southern Asia, High Asia and Africa and should be regarded as a transitional region (various views briefly summarised in Mirza (1994b; 1995)). Zoogeography is dealt with here in the individual species accounts with some mention in the drainage basin accounts.
The ichthyology of neighbouring countries is summarized in various works; these are mentioned in the introduction to the Bibliography.
Iraq has only a small coastline on the Arabian (= Persian) Gulf and traditionally freshwater fishes have been the primary and preferred form of fish food. Masgouf (or mazgouf) is an Iraqi delicacy, particularly in Baghdad (Sabah, 2006). A member of the carp family (Cyprinidae) is degutted, split along the back, salted and woven onto stakes over an open fire of pomegranate wood for roasting. Originally these would have been native species but modern photographs often show Cyprinus carpio, due to a decline in availability of indigenous species in local markets. Salted and sun-dried fish hung on lines date back to Sumerian times. When required the fish was boiled in water and eaten with rice and, in modern times, boiled in tomato juice and eaten with bread or rice.
Various sources give different values for catches so figures from any source should be regarded as evidence of trends rather than absolute values. Al-Noor (2005b) gives the total freshwater catch as follows:-
|
Year |
Catch (tonnes) |
| 1994 | 20,906 |
| 1995 | 22,955 |
| 1996 | 19,049 |
| 1997 | 21,338 |
| 1998 | 9101 |
| 1999 | 11,730 |
| 2000 | 10,122 |
| 2001 | 11,794 |
| 2002 | 13,884 |
and gives catches in tonnes by selected species before marshes were drained as follows:-
| Year/Species | Barbus grypus | Barbus sharpeyi | Barbus xanthopterus | Barbus esocinus | Other species | Total |
| 1965 | 943 | 2516 | 2738 | 388 | 4301 | 10,886 |
| 1966 | 660 | 2653 | 1809 | 333 | 6171 | 11,626 |
| 1967 | 336 | 1706 | 1533 | 128 | 2095 | 5798 |
| 1968 | 747 | 4040 | 2634 | 143 | 76 | 7640 |
| 1969 | 951 | 3667 | 4788 | 17 | 4552 | 13,975 |
| 1970 | 1475 | 7000 | 5797 | 49 | 6062 | 20,404 |
| 1971 | 1338 | 7225 | 3054 | 240 | 4749 | 16,606 |
| 1972 | 1052 | 6801 | 2439 | 40 | 7736 | 20,868 |
| 1973 | 438 | 4914 | 3084 | 41 | 4135 | 12,612 |
| 1974 | 197 | 4019 | 1703 | 59 | 3466 | 9444 |
The Food and Agriculture Organization (http://faostat.fao.org, downloaded 13 November 2005) gives total freshwater catches:-
|
Year |
tonnes |
Year |
tonnes |
|
1982 |
17,000 |
1993 |
21,808 |
|
1983 |
16,500 |
1994 |
25,026 |
|
1984 |
16,000 |
1995 |
25,555 |
|
1985 |
15,941 |
1996 |
21,549 |
|
1986 |
15,564 |
1997 |
23,919 |
|
1987 |
16,250 |
1998 |
16,611 |
|
1988 |
21,461 |
1999 |
11,513 |
|
1989 |
20,938 |
2000 |
10,123 |
|
1990 |
20,475 |
2001 |
16,100 |
|
1991 |
15,110 |
2002 |
13,900 |
|
1992 |
22,280 |
2003 |
14,700 |
Historically the freshwater fisheries have had a much higher yield but political disruptions and drainage of the southern marshes has severely affected the fisheries. Per capita fish supply (including marine fisheries and aquaculture) is 1.0 kg, very low compared to 14 kg internationally (Feid, 2003). The number of licenses issued for inland water fisheries in 2001 was 15,960. Minimum net size is 50 mm stretched mesh. Fish farming licenses issued in 2001 numbered 1893, mainly in Baghdad and adjacent areas, the3 southern provinces being neglected in this regard, although only about 25% of 7500 ha of fish farms were operational in 2003. Catch, production and marketing of fish products is carried out by the private sector with prices set by the local market (www.fao.org, downloaded 19 September 2005).
It was estimated that 30,000 t (Herzog, 1967) were produced in 1966 from inland freshwater fisheries as many fish were sold in small communities and not recorded for the larger markets. These latter showed catches to comprise, in 1965, 943 t of shabout, 2516 t of binni, 2738 t of gattan, 388 t of bizz (as listed above) and 5 t of himri. Catfish are not consumed but some 40-50 t were exported to Lebanon (www.fao.org//docrep/005/50319e/50319e01htm, downloaded 24 October 2005).
Szczerbowski et al. (2001) recorded catches by 1682 fishermen on Lake Tharthar in 1982-1983 fishing for 200 days to be 1600 tons/year or about 8 kg/ha, considered a high yield. In Lake Habbaniyah the yield was probably 20 kg/ha and in Lake Razzazah about 15 kg/ha. Given the productivity of these lakes and the high yields, catches cannot be increased by increasing exploitation intensity.
The Ashar wholesale fish market in Basrah handled 1557 tons per annum in the mid-1960s and in the mid-1970s the freshwater fish on sale in order of importance were Barbus sharpeyi, B. xanthopterus, B. luteus, B. grypus, Liza abu, L. dussumieri, Aspius vorax and Cyprinus carpio. Tenualosa ilisha, Stromateus niger, Pampus argenteus and Acanthopagrus berda led the marine fish sales (Al-Nasiri and Sharma, 1977). Barbus xanthopterus is the most expensive fish followed by B. sharpeyi, Pampus argenteus, Tenualosa ilisha, Cyprinus carpio and Barbus grypus. June is the month with the highest quantity of fish received for sale. Barbus sharpeyi, B. xanthopterus, B. luteus, B. grypus, Liza abu and Aspius vorax are available year round. Barbus sharpeyi forms the largest catch at almost 320 t, followed by Tenualosa ilisha (>280 t), B. xanthopterus (230 t), B. luteus (149 t) and Liza dussumieri at 110 t. Other species are caught at less than 80 t. Sharma (1980) also summarises species importance and market amounts at Basrah in the mid-1970s. Species in Iraq of commercial value in recent years are Barbus grypus, B. sharpeyi, B. xanthopterus, B. esocinus and B. luteus ( www.fao.org//docrep/005/50319e/50319e01htm, downloaded 24 October 2005).
Prices of fish in December 2003 taken from www.iraq-today.com, downloaded 13 November 2005, were given as current (and before the war) in Iraqi dinars per kg:- Cyprinus carpio 3000 (1800), Barbus grypus, 4500 (2750), Barbus xanthopterus 4000 (2750), Barbus sharpeyi 6000 (3500), Hypophthalmichthys molitrix 2200 (1200) and Ctenopharyngodon idella 2500 (1500).
Occupation soldiers in 2004-2005 sent me photographs of fishes they were catching for identification. American anglers using spoons and other actively retrieved bait caught mostly Aspius vorax, a predator, with some Barbus grypus, a species also known to take fishes as well as the large predatory Barbus esocinus. Curiously, British soldiers using passive gear such as bread bait also caught Barbus esocinus.
Some of the various techniques and nets used in Iraq are as follows. Seines called karfa or garfa described by van den Eelaart (1954) measured 150-225 m long and 10-14 m deep with a 4-7 cm mesh used in rivers, 60-120 m long and 4-6 m deep in lakes and marshes, and in Lake Habbaniyah 800-1200 m seines 8-9 m deep were used. Hiyala was a drift net used in rivers or open deep lakes, measuring 50-200 m long and 5-10 m deep with a mesh size of 5-12 cm . Tayar was a gill net 20-25 m long, 2.5-3.0 m deep with a mesh size of 6-10 cm used in shallow waters fixed to poles. Seliya, silliye or hadafi was a cast net 2-3 m wide with a 2.5 cm mesh. Sissi or sisse was a fine mesh drag-net 10-12 m log and 2 m wide used during periods of low water. Chiha was dip-net used in broad rivers and taruf a rectangular dip-net 4 m long and 2 m wide used in shallow marshes. Dissid was a small crossbow net about 1.5 m in width used in slow moving water in a canal or marsh. It was placed in a compartment half way along a reed barrier that fish followed trying to find a passage. The fish entering the net touched a stick, ringing a bell to alert the fisherman lying on a pile of floating reeds. Maddih was a longline with 200-250 hooks baited with boiled potatoes, bran and sometimes dates. Tahar was a line with ten hooks baited with meat, bilid was a line 3-4 hooks baited with meat, and shas a line with one hook. Gargor or kerkur was a small round trap made of reeds. Felleh was a spear or pike with five barbed hooks used at low water. Fish area attracted within range by food thrown in the water and by attraction to lights at night (Jawad, 2006). Kelan was a fish trap used on the Shatt al Arab and made of the leaf stalks of date palms Two types of kelan were used, one with a leader at right angles to the bank and one with two leaders, one parallel to the bank, the other slanting towards it at an angle The kelan was used between November and April and rebuilt the following year. Al-zahar or zahar was a process and a poison. The seeds of a black berry called zahar were used, being ground and mixed with small balls of boiled bran. The neem tree (Azadirachta indica, family Meliaceae) is also used in poisoning, crushed parts being mixed with dough and thrown in the water. Fish eating either mixture are either killed or paralysed and float to the surface. Salvaged mines and explosives from recent wars have been used in northern Iraq for fishing although this practice is now banned and has declined (Carstairs, 2001).Another illegal method is to use a light at night to blind and confuse a fish which is then jabbed by a wire connected to a battery or generator, enabling the fish to be scooped up with a net (www.estripes.com, downloaded 6 September 2006
Catches in order of importance in marshes during the 1960s were Barbus sharpeyi, B. xanthopterus, B. luteus and B. grypus. The marshes were dominated in their refilling phase in 2004 by Silurus triostegus, Carassius auratus and Cyprinus carpio, the latter two species being exotics (USAID, 2004). In the Hawr al Hawizah, the fish catch was dominated by Barbus luteus, B. sharpeyi and Carassius auratus (www.iraqmarshes.org, April 2005 USAID Report).
The marshes provided about 60% of the fishes eaten in Iraq (www.fao.org, downloaded 19 September 2005). Traditionally spears were used in the marshes along with datura mixed into pellets or shrimp bait as a stupefying poison. Lamps were attached to canoes to attract fish and Liza abu would jump into boats. Cast nets or silliya were also used (Salim, 1962). Salim (1962) gives details of cooperative fishing ventures in the marshes. Seine nets were also used, drift nets on rivers and long fixed stake nets (USAID, 2004). Trap nets had bells on them to advise fishermen that a large fish was in the net (Salim, 1962). Smaller pot traps, often baited with dough or unwanted fish, were also used (Jawad, 2006). Reed islands were encircled by a net and the reeds set on fire to drive the fish into the net (al-suwaise). Diving and catching larger fish by hand from under reed islands was also effective (al-tawamees). Small areas of the marsh could be dammed by mud leaving an exit with netting and empty cans to warn the fisherman that a fish had entered the net (al-shiah). Various natural and man-made poisons have been used and even stirring up anoxic mud will poison or stifle fish and allow them to be caught (al-zahar). Gill nets could be several hundred metres long. They were anchored to shore and payed out from a small boat. Catches could attain 2500 kg. Gill nets had 5-7 cm meshes before the marshes were drained but in 2004 only 2-3 cm meshes were effective at catching fish. Legal gill net meshes had seven holes to the foot (suba'e gill net after the Arabic for seven, suba'a) and illegal nets were called hedash (for eleven holes per foot, after the Arabic for eleven, heda'ash). Fish were driven towards the net by banging on tin cans (Jawad, 2006). Seines used in the marshes were up to 100 m long and 6-7 m deep with 20-50 pockets (Jawad, 2006). Fish are difficult to catch at flood times when they are widely spread through the marshes but were easy to catch when they concentrate to return to the rivers during the dry season or are stranded in confined water bodies. Barrier nets are used across the migration routes.
Fish in the marshes and neighbouring rivers are divided into three types (USAID, 2004). Whitefish (not Coregonus spp., or any other taxon) are those that live in rivers and migrate seasonally to the marshes or upriver for feeding and/or reproduction, e.g. Barbus grypus, B. xanthopterus. Those that enter the marshes are not tolerant of dry season conditions and return to the rivers. Blackfish are more tolerant and do not migrate as extensively and may remain in the marshes in the dry season, e.g. Barbus sharpeyi, B. luteus. Greyfish are intermediate in their habits.
Aquaculture was introduced to Iraq in the mid-1950s but only expanded significantly in the late 1970s. It is concentrated in the central part of the country. Al-Hamed (1967), Al-Daham (1985), White (1988), Al-Nasiri (1995) and Hassen (1995) reviewed fish culture practices and possibilities in Iraq. There were 105 fish farms in the late 1970s and, by the late 1990s, 1900 (Feidi, 2003). Aquaculture produced a mean annual production of 4000 t from 1986 to 1997, was 3400 t in 1997, 7500 t in 1998, 2183 t in 1999 and 1745 t in 2000, with the main species being predominately Cyprinus carpio, and also some Hypophthalmichthys molitrix and Ctenopharyngodon idella. Most farms are earth ponds of about 5-10 ha with productivity low at 1400-2000 kg/ha through absence of appropriate fish feed (Feidi, 2003; Kitto and Tabish, 2004; Kitto and Tabish in www.enaca.org, downloaded 10 October 2005). Cage farming was tried in Lake Habbaniyah but is no longer commercially viable and is used for research (El Gamal, 2001). Brackish Lake Razzazah was considered for tilapia farming (Scott, 1995). However Iraq was only responsible for 2% of the aquaculture production in the Near East (El Gamal, 2001).
Cormorants take many fish from fish farms, up to 500 g in weight for common carp, and up to 100% losses at some ponds (Salah et al., 1990).
Fish farms proved profitable after the American occupation, yielding a reputed and most probably exaggerated $8500 in six months from a single small pool. Pollution had made river fish less popular. Fish rustling from farms is now a problem (www.businessreport.co.za, downloaded 19 September 2005; www.aliraqi.org, downloaded 25 July 2006).
Various illegal methods of capturing fish have been employed, small mesh sizes, poisons and explosives, and fishing during the closed season (Mietle, 1967; Jawad, 2003b). Nets for Tenualosa ilisha can extend across the whole Shatt al Arab. Overfishing is common and Evans (1994), for example, reports this happening at Tharthar Lake.
Certain species are not fished for as they lack scales (or have scales so small that they are perceived as scaleless) and as such are haram or forbidden to Moslems. These include the scaleless catfishes and Mastacembelus mastacembelus (finely-scaled). There are also days and times when fishing is not allowed such as Fridays, three days at the end of Ramadan, reduced activity during Ramadan because of daytime fasting, three days at the Eid, and for Shi'ites during the month of Moharram.
The common names of fishes vary with language between countries and within a country with local usage. This problem is overcome to the scientists’ satisfaction by the scientific name, consisting of two words, the genus name and the specific or trivial name. A genus, e.g. Barbus, may contain many species but each species is a unique combination of Barbus and a specific or trivial name. This scientific name is used the world over whatever the local common name may be. It is always written in Latin script and the genus and trivial names are derived from and spelt according to rules of grammar in Latin and Classical Greek. Both these languages are “dead” so the rules and spelling are fixed and not subject to change with time as modern languages are. It is generally felt that the advantages of this system outweigh the unfamiliarity of Latin and Greek words and grammar for most people.
As an example of the scientific name, we can consider Capoeta damascina. This species was first described in 1842 by Achille Valenciennes in an extensive co-authored work with Baron Georges Léopold Chrétien Frédéric Dagobert Cuvier, who by this time was dead (see History of Research above). However, the species was described originally in the genus Gobio as Gobio damascinus and subsequent research showed that the it belongs in Capoeta – the authors names and the date of description are placed in parentheses to show this change in genus. Gobio is masculine and Capoeta feminine so the –us ending of damascinus was changed to an –a. Note also that it is now more usual simply to cite the name of the person who described the species (as Valenciennes,1842) since the authorship of species in many major works has been carefully attributed and on-line sources such as Catalog of Fishes (at www.calacademy.org/research/ichthyology/catalog/) make searches of authorships and dates much easier.
The scientific name is used to show relationships between species as noted above and can therefore be altered if views on the relationships of the species are changed according to the “International Code of Zoological Nomenclature”. The Fourth Edition of the Code came into effect on 1 January 2000. Errors also arise in giving species scientific names and these must be corrected by name changes according to the Code. The Code is complicated and detailed explanations based on fishes may be found in Eschmeyer (1998). Some of the more common reasons for name changes are given below.
A single species may be described twice, either by the same person or by two people. At the time of these descriptions it was genuinely believed that there were two species but subsequent studies showed that they were the same. This error often arises with confusion between juveniles and adults and between males and females which may be quite different in appearance. Older collections from remote areas often comprised only a few specimens and could be in rather poor condition by the time they came into the hands of an ichthyologist and were described scientifically. It is also possible, where two people are concerned, that the author who published his description later was ignorant of the first author’s work. The first name published has priority and the second name is called a synonym and is no longer used. There may be several synonyms for a species. These are listed in the species descriptions. There is also the problem of misidentification of specimens. When these specimens are available for study identification can be confirmed (or amended) but often specimens are discarded or lost. These errors too may be listed in a synonymy. Krupp (1984a) gives a synonymy for Aphanius cypris which amply illustrates how a scientific name may be mis-applied (there are 89 uses of names which all refer to one species in Krupp’s opinion). A. cypris is now thought to be correctly named A. mento.
Occasionally the same name is given to two distinct species because the later author was not aware that the name had already been used. The name of the species described first is called a senior homonym and is retained while the later species name, the junior homonym, must by replaced.
The genus name of a species can be changed because an ichthyologist, who has studied the species and its relatives in detail, considers that it is more closely related to another species or group of species with a distinct genus name. A case of this was discussed above with Gobio damascinus where a new genus was used for this species. The species placed in a different genus will retain its trivial or species name unless this trivial name is already in use in the different genus. Homonymy has then occurred and the species which has priority retains its trivial name and a replacement name must be given to the more recently described species. It is not unusual for scientists to disagree about the interpretation of the same data and a species may have a long and complex career being switched from genus to genus as publications advocate one view or another of its relationships.
There is a higher classification which groups together related genera into Families, Families into Orders and Orders into Classes. The vast majority of Iraqi freshwater fishes belong to the Class Actinopterygii, the ray-finned bony fishes, with only the bull shark being in a second Class Chondrichthyes or cartilaginous fishes.
A knowledge of fish anatomy is essential in identifying specimens. The head of a fish carries a number of structures. The eyes are without eyelids although sharks have a protective membrane, the nictitating membrane, which acts as an eyelid. Eye size varies with age within a species but can also be a distinguishing characteristic between species. There are nostrils, for detecting odours, on the snout, that part of the head before the eyes. Nostrils are blind sacs and do not connect with the mouth cavity. Their position and shape may be useful characters. Barbels are slender, fleshy structures on the snout or chin used for touch and taste. Their presence, number, position and length are important characters. Sharks and sturgeons have a small opening near the eye called the spiracle, not found in the bony fishes. Teeth may be found variously on the tongue, roof and floor of the mouth and even in the throat. The pharyngeal teeth of Cyprinidae are often useful characters in identification and may be dissected out from the posterior part of the gill cavity under the operculum using dissecting equipment. This requires some practice to avoid damaging the specimen too extensively. Some teeth are sharp and pointed for piercing and holding prey, while others are rounded and heavy for crushing food items covered by a protective shell. The side of the head behind the eye is the gill cover in bony fishes, composed mainly of one bone, the opercle, which protects the gills. The gill cover opens posteriorly; bony fishes have one opening on each side of the head, but lampreys have seven rounded openings and sharks five to seven vertical slits. The cheek is the area between the gill cover and the eye. Spines and scales may be found at various places on the gill cover and cheek. A membrane is found below the gill cover, supported by thin slivers of bone, the branchiostegals, and connected with the gill cover on the other side of the head. Under the gill cover lie the gills which serve in gaseous exchange. Gill rakers on the front of each gill arch serve to prevent food from damaging the gills and direct food into the gut. Rakers may be short and widely spaced where food items are large and easily deflected, or long and close together where food items are minute like plankton.
The head leads directly to the body; there is no neck. The body is made up mostly of a trunk. The caudal peduncle or tail stem starts behind the anal fin and ends at the tail fin. The number and presence of different types of fins on the body varies with the species of fish and is often a useful character for identification. The back may carry 1-3 dorsal fins and an adipose fin between the last dorsal fin and the tail fin. The tail (or caudal) fin is at the end of the body and may be forked, square cut, rounded, pointed, lanceolate or lunate. Its skeletal structure may be almost symmetrical or upturned at the end. This upturn is obvious in sharks and sturgeons which also have a large upper lobe to the tail fin and a smaller lower lobe. The anal fin, or fins, lies on the underside of the body surface behind the vent which is the exit for the intestine, kidney ducts and gonads. The pectoral fins are found behind the gill cover on each side of the body and a pair of pelvic fins are behind (abdominal), below (thoracic), or in front (jugular) of the pectorals on the lower body surface. An axillary pelvic scale above the pelvic fin streamlines the fin when it is pressed against the body. The pectoral fin may also have an axillary scale. All the fins except the fleshy adipose fin are supported by rays. Soft rays are flexible and jointed while spines are rigid, pointed and unjointed. The number of soft rays and spines in the various fins is very useful for identification.
Most fishes have a body covering of scales which may extend onto the head and certain fins. Notable exceptions are the catfish families Bagridae, Siluridae, Sisoridae and Heteropneustidae, which are completely naked. Rounded, smooth scales are called cycloid and are found in less advanced bony fishes. Large cycloid scales may easily detach, as in herrings (Clupeidae) but small cycloid scales can be embedded and hard to see as in the eel (Anguillidae). Ctenoid scales bear small teeth on the posterior margin and feel rough to the touch. Such scales are found in the more advanced bony fishes. Sharks have placoid scales which can be so rough as to scrape the skin off a human. The teeth of sharks are modified placoid scales. Scales grow with the fish, laying down rings of material as do trees. In areas with a change of seasons, the growth rings are widely spaced during the summer growing season and cramped together in winter when growth is slow. Fish age can be determined from these rings. The energy expended in spawning is reflected in the scales which may resorb the edge producing a spawning check. A fish which lives and grows slowly in fresh water and then migrates to the rich feeding grounds of the sea will have this history reflected in the spacing of the growth rings. Scales can be “read” to reveal much about the life history of an individual fish. The scales also bear radii, or radiating lines, and their distribution can be useful in identification along with other scale characters such as shape and focus (growth origin) position. The scales are covered by an almost undetectable layer of skin. The skin contains mucus cells which give the fish a slippery feel and colour cells which give the fish its colour. Some fish are characteristically more slimy than others. Most fish have a distinctive colour pattern but this can change with age, maturity, behaviour, background, between sexes, and after death.
Fishes have a sensory lateral line system which runs along the flank and a similar system on the head. The extent and development of these systems varies with the species of fish. The lateral line is a tube in the skin with openings to the outside through pores in the scales. A lateral line pore count is often used in separating fish species.
The internal structure of a fish may be summarised as follows. The gills and teeth have already been mentioned. After these structures, the mouth cavity narrows to an oesophagus which passes to a straight, U- or J-shaped stomach. Pyloric caeca, which produce enzymes, may be attached at the junction of the stomach and intestine in some fishes and counts of these caeca are used in identification of some species. The intestine ends at the vent. The length of the intestine varies with the diet. Fishes which feed on plant material have long guts while those that feed on animals have a short, often s-shaped intestine. Fish have a liver, a reddish organ at the front of the body cavity. The liver may be very large in sharks and form a significant part of the body weight. There may be a small, green gall-bladder associated with the liver. The swimbladder (gasbladder) is a gas-filled sac with thin walls lying near the top of the body cavity where it functions as a buoyancy organ and can be used to transmit sounds to the brain or even produce sounds by means of special drumming muscles. The swimbladder shape has been used to characterize species. Some fishes have a poorly developed swimbladder or none at all, since they live on the bottom of stream beds and must avoid being swept away. Just below the backbone above the swimbladder are two long, dark-coloured kidneys and below these are the ovaries, which may be filled with eggs, or the testes which produce the sperm. A small urinary bladder lies at the end of the body cavity. The body cavity is lined with a membrane which may vary in colour from silvery-white to jet black. The main body muscles are in the form of W-shaped, interlocking blocks and this arrangement helps produce the sinuous body movements by which fish swim.
Sharks also have a somewhat different structure from bony fishes. Some species produce living young rather than eggs, while in others the embryo is laid in a horny egg-case known as a mermaid’s purse when it washes up on a beach. Male sharks have claspers derived from the pelvic fins, which serve to ensure that sperm are delivered to the female. The length of time food stays in the gut of sharks, and also sturgeons, is increased by a spiral valve. The food follows the spiral around rather than going straight through the gut and so there is more time for digestion and absorption. There is no swimbladder in sharks, which have to swim constantly to stay above the bottom. Sharks produce teeth in multiple rows, and as older teeth at the front of the jaw fall out, new ones move forward to replace them.
The skeleton includes the skull comprising the cranium, which contains the brain, the jaws, gill arches, operculum and other associated bones. The cranium also contains small objects known as otoliths in the inner ear. These aid in sensing change of direction and in balance. Otoliths can be characteristic of species. There is a vertebral column with ribs anteriorly enclosing and protecting the body cavity and its contents. The number of vertebrae is a useful character and can be counted easily, without damage to the fish, by taking x-rays. A tail skeleton supports the tail fin and the pectoral and pelvic girdles support their respective fins. There are fin supports too for the dorsal and anal fins. Lampreys, sharks and sturgeons have a skeleton composed of cartilage, a substance not as strong as bone, but when impregnated with salts (like shark teeth) are remarkably effective.
Most characters used for fish identification are external for convenience. The most used internal characters are gill raker counts, pharyngeal teeth counts, gut shape and body cavity lining colour, pyloric caeca counts and vertebral counts.
The general structure and biology of fishes is covered in various general works. Coad (1993; 1995b) gives a list of general ichthyology texts and the Dictionary of Ichthyology at www.briancoad.com describes various anatomical terms.
Collecting and Preserving Fishes
Collecting methods and literature are summarized by Coad (1993; 1995b). Luck plays a part even in scientific collecting as discovery of new species in areas previously sampled demonstrates. Repeated visits to areas already sampled may prove rewarding. Many areas of Iraq have not been fully explored, particularly with reference to the smaller, non-commercial species. New species still remain to be discovered and it is important to document them properly as explained below.
Captured fishes which cannot be identified or seem unusual enough to warrant further attention should be preserved. Labeled, preserved specimens deposited in a museum are a permanent record of species identity and distribution. Some taxa present problems of identification even for experts so that misidentifications are often a nuisance if there is no material to examine. Samples from ecological or experimental studies as well as systematic and distributional works may be preserved and sent to a museum where their identity can be confirmed and where they are available to workers in the future. Major museums in a number of countries welcome exotic material to enhance the variety of their collections.
Specimens should be preserved whole, without removal of the guts or gills so that no key characters are lost. Specimens may be frozen, or even salted, but the best method and the one used by scientists is to drop fish into 1 part full-strength formalin to kill the fish quickly and then immediately add 9 parts of water to form a 10% preserving solution. Large specimens (larger than about 15 cm) should have a small slit made in the right side of the belly to allow formalin to penetrate the tissues. Ichthyologists cut the right side of the fish and leave the left side undamaged for illustration and scale counting. Hypodermic syringes are used to inject the abdominal cavity and muscle blocks of very large fish with formalin, otherwise the preservative will not penetrate all the tissues before decay sets in. This is especially important in a hot climate like that of Iraq. Syringes should have a capacity of up to 100 ml and be capable of taking needles of various sizes. Particular care should be taken when injecting formalin into tissues; the needle should be withdrawn gradually while injecting the formalin solution to avoid a sudden spurt of liquid under pressure from the injection site.
Formalin should be handled with care as it is a noxious chemical which irritates the eyes and nose and is painful in skin cuts. It may be carcinogenic and repeated exposure can trigger allergic reactions in the skin. Gloves and safety glasses are useful when diluting full-strength formalin. It should only be handled in well-ventilated rooms or in the open air. In the field, care should be exercised in packing specimens for transport so that leakages do not occur. Long-term preservation in formalin is not advisable as the solution becomes acidic and rots the fish. It also wrinkles and hardens the specimens.
Wherever possible some specimens or tissue parts should be preserved in 95+% ethanol for potential molecular studies. Modern DNA techniques may be the only way to resolve some systematic problems as morphology has proved inadequate. If a tissue sample is taken, the whole fish should also be preserved as a voucher specimen for confirmation of identity.
Most museums store their specimens in alcohol for the long term. The formalin-fixed specimens are washed briefly in water and then transferred to 45% iso-propyl alcohol or 70% ethanol. These chemicals are pleasanter to work with. Some care should be taken such that specimens are not twisted and bent inside the preserving container. It is difficult to make counts and measurements necessary for identification on badly deformed specimens. Each specimen or group of specimens should have at least an equal volume of preservative as water in the fish tissues tends to dilute the preserving fluid. Specimens may be stepped through 30%, 50% and 70% alcohol solutions to reduce wrinkling and ensure a fuller penetration of alcohol into tissues and a final storage solution of at least 70% ethanol. Ethanol may be difficult to obtain in Islamic countries and undrinkable iso-propyl alcohol can be substituted.
The best containers for long-term storage are made of glass with tightly-sealing polypropylene lids. Plastic containers deteriorate with time and tend to crack. Metal containers and metal lids eventually rust. In the field, large plastic buckets with tightly-sealed lids are less likely to break than glass containers and are not as heavy. Very large fish may require some sort of drum, such as a clean oil drum but it should be noted that formalin corrodes metal and the drums should be lined with plastic or lacquered. Fluid levels in the collection should be checked regularly and alcohol concentrations maintained at the recommended values or the specimens will deteriorate. Collections should be kept in the dark to reduce fading of pigments and at a constant, cool temperature.
Fish which have been preserved for a week in formalin, more for larger fishes, or transferred to alcohol can be sent to a museum for identification. Glass containers full of formalin or alcohol should not be mailed because of the danger of breakage. The fish should be wrapped in cheesecloth or some other absorbent packaging, with its label, the cheesecloth dampened with preservative, and tightly sealed in several, leak-proof plastic bags before being placed in a padded box for mailing. Spiny fish should be especially well wrapped to avoid puncturing the plastic bags. A tightly-sealed package retains the preservative which keeps the fish in good condition. The box may be labeled “Scientific specimens, no commercial value”.
The label is as important as the fish itself. An interesting specimen is of little or no scientific value if there is no locality data. Labels should be written at the time of capture. Faulty memory and good intentions to label specimens later make a poor combination and often result in collections with no data, or worse with incorrect data. The label should bear the place of capture, such as a stream, lake, spring, etc., including a reference to the nearest town (local names may not be on maps or in gazetteers and some village names are very common), latitude and longitude (a GPS or Global Positioning System can ensure an accurate locality), province, date, name of collector, notes on the habitat and live colour of the specimens, and any other items likely to be useful. Colour photographs of fresh fish are most useful, especially if the fins are pinned erect. Pencil or India ink should be used on stout, waterproof paper which will not disintegrate in liquid. The label must be dropped in the jar with the fish. Labels on the outside of jars always fall off and lids with labels always get put on the wrong jar!
In fact the amount of information which should be usefully recorded cannot be put on a small label. Instead extensive field sheets are used and related to the specimen or sample by a field number. The Canadian Museum of Nature, Ottawa has field sheets with over 70 categories which can, potentially, be filled in and some categories have as many as 30 alternatives, e.g. Category 17, Environment includes fresh spring, cave, canal, stream/river, river-lake junction, flooded area, fresh pool, pond, lake, marsh (treeless), swamp (with trees), reservoir, ditch, etc. As an insurance against loss of field sheets or confusion of numbers, the jar label should carry minimal locality data as well as the field number.
It is essential that a collector obtain the necessary licences for scientific purposes from the appropriate authorities. Closed seasons for fishing in Iraq are 15 February to 1 May in southern areas, 1 March to 15 May in central areas and 1 April to 15 June in northern areas (www.fao.org, downloaded 19 September 2005). USAID (2004) gives 15 February to 15 April, 1 April to 1 June, and 1 June to 1 July! Minimum legal sizes (total length) for Barbus sharpeyi are 30 cm, and for B, grypus and B. xanthopterus 45 cm (USAID, 2004). Regulations existed for commercial fishing (ca. 1965) too such as use of nets with less than 6.5 cm meshes, prohibition of use of fishing gear across a whole stretch of water, distance between nets not less than 100 m, seasonal restrictions on fishing, prohibition of fishing gattan and shabout less than 40 cm, binni less than 30 cm, carp less than 30 cm, licensing of wholesalers and retailers, and renewal of old licences and issuing new licences. Joosten (2003) however states that the few conservation laws, including restrictions on fishing, were never implemented or enforced.
© Brian W. Coad (www.briancoad.com)