Freshwater Fishes of Iran
Introduction - Habitats
The major rivers of Iran drain the two mountain chains which retain enough snow or collect enough rainfall to ensure a constant and appreciable flow. All rivers in Iran are fordable on foot when not in spring flood with the exception of the Aras and Safid rivers of the Caspian basin, the Hirmand river of Sistan and the large rivers of Khuzestan. Most rivers marked on maps are in reality small streams, with very shallow and clear water. There is little vegetation on the banks, and fishes, if present, can be seen with ease. A significant proportion of fish habitat is occupied by small streams, springs and qanats. Large freshwater lakes or marshes are absent except in Sistan, the Caspian basin and the plains of Khuzestan. Most large lakes on maps are salty and do not support a fish fauna. A number of dams have been built and more are planned (see Bagley (1976), Coad (1980c) and "Aquastat" from the Food and Agriculture Organization, Rome (http://www.fao.org/ag/agl/aglw/aquastat/iran.htm)) and these form important lacustrine habitats. In 1994, 27 storage dams were in operation with a capacity of 39.2 km3 and a further 24 were under construction with a capacity of 11.5 km3 (see also below for more on dams). In 2002 Iran was building 68 dams and the construction of a further 120 dams were being considered as 33% of the country's water resources were wasted (IRNA, 2 January 2002). Manouchehri and Mahmoodian (2002) briefly review environmental impacts of dams in Iran.
The streams may have their origin in a mountain, a spring or a qanat, but they hold in common a clarity of water, a bare pebble bed, small dimensions (one to a few metres wide and a few centimetres deep) and often a short course. They may join another stream but are often lost in marshes, tapped for irrigation and lost in fields or become absorbed by the friable and porous ground. Many streams are intermittent, with flow near their mountain source, dry sections and perhaps a flow near their mid-course, with subsequent absorption into the ground. Heavy aquatic vegetation is not common and most plant material is a thin encrusting layer on the bottom. Banks are often bare of riparian vegetation and streams are fully exposed to insolation. Summer temperatures are often high as a result (30°C and more) yet at higher altitudes streams can be icy cold even in summer and the typical blue-grey of snow-fed water. Spring floods can be disastrous, scouring out the stream beds and dumping heavy silt loads (Melville, 1984). Spring fed streams of shorter course are not affected because they have a small catchment area and may well provide a refuge for fishes. The clean water of springs attracts human settlement and these waters are often blocked off to form ponds or cisterns with water led off through artificial channels subject to drying as requirements change. Streams and rivers may also be impounded, forming small ponds or lakes. Bridges often have small pools beneath them and this may be the deepest (at ca. 1 m) and most shaded section of a stream.
Marsh areas may be associated with springs. Reeds and other vegetation develop downstream of the source and may be quite extensive, occupying several square kilometres. Some areas of marsh are ponded and provide habitat for larger species as well as shelter for young. Extensive marshes, lakes and lagoons are developed in Sistan, the Caspian basin and Khuzestan, all fed by major rivers (50+ m wide and 3+ m deep) draining vast areas of land. These areas vary widely with season and flood dramatically in spring, inundating vast tracts of land. The rivers and associated marsh-lake complexes provide the major freshwater food fishing areas in Iran. The Sistan marshes have been described in Annandale (1921) and Annandale and Hora (1920), the Caspian shore by Schüz (1959) and the lowlands of southern Iraq by Rzóska (1980) and by Thesiger (1985) and Young (1989).
Conservation of aquatic habitats in Iran has been part of a general programme for biotic conservation summarised in Firouz (1974; 1976), Firouz and Harrington (1976), Ashtiani-Zarandi (1990) and Kahrom (2000). The Ramsar Convention on Wetlands of International Importance was named after the city of Ramsar in northern Iran where the first conference was held in January 1971. Iran has more Ramsar listed sites than any other country in Southwest Asia (Scott, 1993). In 1977 there were 11 Park-e Melli (National Parks), 4 Asar-e Tabii Melli (National Nature Monuments), 24 Manatgheh-Hefazat Shodeh (Protected Regions or Areas) and 31 Panahgah-e hayat-e Vahsh (Wildlife Refuges) offering varying degrees of protection to the fish fauna (Firouz et al., 1970; Yachkaschi, 1976; Köpp and Yachkaschi, 1978; Majnunian, 1985). The 1993 United Nations List of National Parks and Protected Areas at "www.wcmc.org.uk/data/database/un_combo.html lists" 7 National Parks, 2 National Nature Monuments, 41 Protected Areas and 18 Wildlife Refuges and the National Report of the Islamic Republic of Iran for the Convention on Biological Diversity (Department of the Environment, Tehran) lists 11 National Parks, 47 Protected Areas, 25 Wildlife Refuges, 5 National Nature Monuments, 9 MAB (Man and Biosphere) Sites and 20 Ramsar Sites.
Seven Ramsar sites are priorities for urgent action with the causes, namely:- Alagol, Ulmagol and Ajigol lakes (impact of agricultural development), the Anzali Mordab (Talab) complex (falling water levels and increased eutrophication leading to the rapid spread of the reed Phragmites australis, south end of Hamun-e Puzak (water inflow could be reduced because of dam construction in Afghanistan), Hamun-e Saberi and Hamun-e Hirmand (dam construction in Afghanistan), Neyriz lakes and Kamjan Marshes (drought and agricultural activities), Shadegan Marshes and mudflats of Khor al Amaya and Khor Musa (chemical pollution from the Iran-Iraq war), and Shurgol, Yadegarlu and Dorgeh Sangi lakes (war and drought effects) (www.ramsar.org/ram_rpt_37e.htm, downloaded 28 July 2000).
The status of the fish fauna in Iran was assessed by Coad (1980c) and compared with other areas by Moyle and Leidy in Fiedler and Jain (1992). The percentage of the total fauna under some form of threat was assessed at 22%, a figure which was lower than most other areas examined.
Iran has several unusual habitats for fishes and these are described below.
i) Hot springs
A number of hot springs are reported from Iran (Waring, 1965; Joneidi et al., 1971?; www.bibliothecapersica.com/articlenavigation/index.html, under ab-e garm, downloaded 24 December 2004). Some of the hot springs marked on maps are not hot, e.g. the spring at Tafresh (ca. 34°44'N, 50°02'E) was only 19°C (and fishless). Some springs produce water at relatively high temperatures, but since these temperatures are also seen in nearby streams they are not regarded as "hot", e.g. a spring near Farrashband (28°53'N, 52°06'E) at 30°C.
Only the true hot spring at Genu (27º26'N, 56º20'E) is known to contain fish including Aphanius ginaonis, Cyprinion watsoni and Garra persica (Coad, 1980b). A hot spring on the slopes of Kuh-e Bazman (the mountain is at 28°04'N, 60°01'E) is rumoured to contain tooth-carps (Cyprinodontidae).
The Ab-e Garm (literally hot water) at Genu emerges at 41°C and was partially enclosed by brickwork associated with a hammam or bath-house. The altitude of the spring is about 400 m. Its stream is 10-15 m wide near the source and the bed is composed of stones and pebbles covered by lime-green algal mats and strings. Only Aphanius ginaonis was found at the hot spring, not in the main flow but along the stream margins and in many minor subsidiary springs which emerge a few metres from the main spring. These minor springs had a mud bottom, were as shallow as 1 cm and had soap and food debris pollution in 1977. Side springs and stream margin near the source were 37-40ºC. The other species (along with A. ginaonis) were found below a cascade and have no access to the hotter parts of the spring and stream. A. dispar is recorded from the spring by Werner (1929) but this has not been confirmed by my collections. The water is clear and colourless, but there is a strong smell of sulphur. Flow is 30 l/sec. The chemistry of this spring as given by Joneidi et al. (1971?) was : pH = 6.2, conductivity 14,000 us, dry residue at 180ºC = 9933 mg/l, H2S = 34 (? p.p.b.), r (reacting value) Ca = 22.4, r Mg = 9.9, r Na + K = 6.1, total cations 162.1 (sic), r Cl = 147, r SO4 = 15.4, r HCO3 = 4.6, total anions = 166 (sic), SiO2 = 10 mg/l, NH4 = 0.7 (no units given), NO3 = 22 (no units given). There were traces of CO2 and no measurable Fe, NO2, or CO3. The hot spring lies in the Genu Protected Area (Biosphere Reserve) which is described by Zehzad et al. (1997).
Iran is replete with caves but thus far only one has been found to contain a fish fauna. This cave lies about 12 km north of the railway station Tang-e Haft in Lorestan at 33°05'N, 48°36'E. Two species are found here, Iranocypris typhlops (Cyprinidae) and Nemacheilus smithi (Balitoridae) (Bruun and Kaiser, 1944; Movaghar, 1973; Greenwood, 1976; Smith, 1978; 1979; Coad, 1996c; Proudlove, 2001; Romero and Paulson, 2001). The cave lies in the Dez River drainage of the Tigris River basin and its connection to nearby surface water is intermittent. The cave is the surface outlet of a subterranean limestone system and the captures may represent strays from underground. B. Sandford (pers. comm., 1979) stated that there is some evidence of recent collapse in the cave system and thus the habitat may be endangered but it is difficult to assess the extent and nature of underground fissures in the rock.
Qanats are an unusual yet important habitat for fishes in Iran. An account of their fishes with an extensive bibliography is given in Coad (1996h); additional literature on this unique environment not referenced there includes Kuros (1943), Aisenstein (1947), Feylessoufi (1959), Nesbitt and Bawa (1960; 1961), de Menasce (1966), Jentsch (1970), Nadji (1970; 1972a; 1972b), Braun (1974), Goblot (1979), Hartl (1979), Sajjadi (1982), Goldsmith and Hildyard (1984), Behnia (1988), McLachlan (1988), Beaumont et al. (1989), Harwit (1990), Razavi (1991), Coad (1994b), Koocheki (1996), Liaqati (1997), Salim Manshadi et al. (1997), Afkhami (1998), English (1998), Aminpouri (2002), www.netiran.com/Htdocs/Clippings/DEconomy/200629XXDE05.html, downloaded 8 August 2002), Foltz (2002), Floor (2003), Wessels and Hoogeveen (2003), and qanats at www.waterhistory.org, and at www.bibliothecapersica.com/articlenavigation/index.html, under abyari (irrigation), downloaded 24 December 2004.
The word qanat has various suggested origins including a derivation from the Akkadian for "reed" according to Goblot (1979) in contrast to others listed in Coad (1996h).
Over 20% of the irrigated area of Iran is fed by qanats (Redding and Midlen, 1991) and numbers as high as 60,000 have been estimated. They are essentially horizontal wells which tap groundwater and provide a continual, low gradient flow of fresh water. Qanats are an advantageous habitat for fishes in several ways. The water temperature is not subject to the extremes found in natural waters, shade within the qanat provides protection against predators on adults, young and eggs and against insolation, the gradient and water flow are gentle, and a certain amount of food is provided by kitchen scraps since dishes, cooking containers and implements are washed in the jube or channel and food is cleaned and trimmed there. A school of fish will quickly gather at a washing site and maintain station in clouds of detergent in order to pick up scraps of food. Attempts to imitate washing movements will attract fish momentarily but they soon dart off when no food is forthcoming. The garden environment with trees and other vegetation provides shade, energy input from leaf fall and garbage items, and facilitates development of an invertebrate fauna as a food source. Aufwuchs on rock surfaces provide a food source along with the associated invertebrate fauna. The Zoroastrian community, once widespread in Iran, has a ceremony known as com-e mahi or "meal for the fishes" in which bread and dried fruit are thrown into running water as a libation (Boyce, 1977). Feeding of scraps to fish is also seen in Moslem communities and boys regularly attempt to attract and catch fish using any available food material and primitive fishing gear (personal observations; Edwards, 1971).
Qanats are now rapidly being replaced by pump-wells which are faster and easier to excavate but do not provide fish habitat. Pump-wells often dry up qanats and natural springs by lowering the water table (Razavi, 1991; Anonymous, 2001b; Aminpouri, 2002). Also schemes to restrict water flow from qanats for conservation reasons will presumably affect the available habitat for fishes (Salim Manshadi et al., 1997).
The qanat fishes comprised 25 species in Coad's study (1996h), 40% of the fauna on the plateau of Iran. The number of species per qanat ranges from 1 to 6 although 88% of qanats have only 1-2 species. Areas with little surface water and low in diversity have 94% of the species occurring in qanats while better-watered areas with more diversity have only 29% of species in qanats. The qanat fauna is dominated by the Cyprinidae, which comprises 76% of the ichthyofauna. The qanat fauna is a subset of the basin in which the qanat occurs, comprising small species, broadcast spawners, lacking in specialised food requirements (usually scrapers of aufwuchs or feeding on invertebrates), non-migratory, and widely tolerant of environmental conditions.
The fishes in qanats are caught by local people for food but given the restricted size of this habitat and of most fishes found in them, this is not a significant dietary item. In the seventeenth century qanat fishes "were not esteemed as they never saw the light and were used only for medicinal purposes to cause vomiting" (Ferrier, 1996, quoting Jean Chardin). In the 1950s villagers in Iran believed that qanat fish lived forever and needed no food, only their own eggs (www.iras.ucalgary.ca/~volk/sylvia/qanat.htm, downloaded 24 June 2002).
Colonisation is both natural, since loaches are unlikely to be seen and caught by local people, and deliberate, since larger cyprinids are found in qanats remote from any surface water. These fish are hardy, already living in high temperature environments, and are easily transported for Now Ruz celebrations. At the Zard-Abieh qanat in Shahrud, a local man remembered putting fish into the qanat 60 years ago from one now dry (H. Rahimian, pers. comm., 2000). Qanats and rivers in south Khorasan contain only Capoeta fusca and Gambusia holbrooki and of 67 qanats and 6 rivers surveyed only 22 qanats and 4 rivers had fish (Johari and Asghari, 2009). Teimori et al. (2009) give a recent review of diversity, threats and conservation status of the qanat fauna.
iv) Salt streams and lakes
Salt lakes are common in Iran and are mostly too saline to support a fish fauna. They are discussed in a world context by Williams (1996). Fishes do exist in tributary streams (which may be saline in varying degrees). Rivers and springs around salt lakes are therefore isolated from one another and might be expected to give rise to unique populations of fishes. However all these salt lakes are shallow and liable to desiccate such that tributary streams and springs can connect and allow faunal interchanges once the lake level falls.
Many streams in Iran are highly mineralized or even salt to taste yet these support fishes which are usually regarded, at least at the family level, as salt intolerant. Salinity tolerance studies have not been carried out on Iranian fishes. The Caspian Sea is at one-third sea water (12-13‰) yet typical "fresh" water species can be found there, e.g. Cyprinus carpio.
v) Sacred waters
A number of springs in Iran are said to be "sacred" and their fish then attain a degree of importance on account of their inaccessibility to ichthyologists. Howz or tanks at Qumisheh (32°01'N, 51°52'E) were supposed to hold sacred fish, decorated with gold rings, according to John Fryer in 1698 and John Chardin in 1711, but G. N. Curzon in 1892 mentioned that the gold rings were gone and by 1978 so were the fish. A sacred tank or artificial reservoir at Soh contained fish deemed to be holy. Visitors were expected to purchase bread to feed these fishes (Anderson, 1880).
The most important "sacred" fish are those of Sa'di's Tomb in Shiraz (29°37'N, 52°35'E) which were described by Heckel (1849b) as new species Scaphiodon saadii (= Capoeta damascina) and Discognathus crenulatus (= Garra rufa). The water is a stream (?qanat) under the tomb and part is expanded into a hawz-e mahi or fish pond. Fish have been present here since at least the early nineteenth century as they are mentioned briefly by Waring (1807). Official permission was gained to collect fishes in Sa'di's tomb for study but sampling was actively discouraged by local people. Sa'di was supposed to punish any killing of these fishes with death but the traveller Chardin was able to catch some to eat by monetary means. Some of these fish too were reputedly decorated with gold rings (Ouseley, 1819-1823); regrettably my captures were not.
A mordab is a fresh or brackish water lagoon area found along the Caspian Sea coast (literally "dead water", the Russian equivalent is liman). The Anzali Mordab at 37°26'N, 49°25'E is the best known (Firouz, 1968b) and was formerly called the Pahlavi Mordab. The more modern term is "talab" (= pool or marsh, which lacks the association with death) but the older literature refers to mordab and the term is still in common use. The Anzali Mordab is about 30 km long and 4-8 km wide with clear water of only 1.5 m average depth. Much of the area is covered by Phragmites reeds and other plants and only about 15% is open water. Variations in Caspian Sea level and water abstraction from feeder streams will affect the mordab level and size. In the 1930s the mordab was 4 to 8 m deep (Vladykov, 1964) and the fall in level has severely affected the spawning migrations of fishes and the habitat for developing young. The mordab is the principal breeding ground for Rutilus frisii kutum and is also important for several other species. Further details are given below under the description of the Caspian Sea basin.
Wetlands were originally studied and protected as feeding and overwintering grounds for important waterfowl but they do protect fish populations which might otherwise be threatened. Access and hunting is forbidden or restricted and often fishing too. Anonymous (1971), Carp (1972) and Dugan (1993) list and describe various wetlands in Iran of international importance principally:-
See also Scott (1995) where latitude-longitudes are often slightly different.
Lower Atrak River and Alagol Lake (37°21'N, 54°35'E)
Farahabad and Larim Sahra (36°45'N, 53°05'E)
Zarrin Kola (36°43'N, 53°00'E)
Bisheh Sar (36°36'N, 52°43'E)
Fereydun Kenar (36°40'N, 52°31'E)
Bandar-e Farahnaz Lagoon (37°25'N, 49°57'E)
Khalij-e Gorgan (36°50'N, 53°40'E)
Anzali Mordab (37°25'N, 49°30'E)
Nur Gol (38°00'N, 48°33'E)
Neyriz Lakes (29°30'N, 53°40'E)
Lake Parishan (Famur)(29°26'N, 51°50'E)
Khuzestan Marshes (30°30'N, 49°30'E)
Dasht-e Arjan (29°35'N, 52°00'E)
Lake Kopibalbalch, Hassanlu Marsh, Yadergarlu Marsh and surrounding marshes (37°00'N, 45°30'E)
Lake Bishovan (37°09'N, 54°52'E)
Amirkelayeh (37°17'N, 50°12'E)
Coastal lagoons north of Gomishan (37°15'N, 54°00'E)
Seyed Mahalleh (36°45'N, 53°00'E)
Sistan lowlands (31°00'N, 61°10'E)
Additional wetlands not of international importance were listed as follows:-
Safid Rud Reservoir (36°45'N, 49°24'E)
Astara (38°25'N, 48°50'E)
Bahr-e Zaribar (35°32'N, 46°07'E)
Soltanabad Marshes (29°30'N, 52°35'E)
Lake Maharlu (29°30'N, 52°50'E)
Dasht-e Mogan (39°30'N, 47°30'E)
Araxes River (39°10'N, 45°20'E)
Agh Gol (39°55'N, 44°47'E)
Rud-e Shur (35º50'N, 50°25'E)
Zarghan and Lapu'i Marshes (29°50'N, 52°50'E)
Other wetlands are mentioned in the appropriate drainage basin account.
© Brian W. Coad (www.briancoad.com)