Herrings, shads, sardines, pilchards and menhadens are moderate-sized fishes, usually less than 25 cm long, found in warmer marine waters with some species anadromous or permanent freshwater residents. There are about 57 genera and 188 species world-wide (Nelson, 2006), with 8 species in the Caspian Sea and 1 commonly found in Persian Gulf drainages. Some other species are known to enter rivers in southern Iran (see Marine List). The diversity of this family in the Caspian Sea is seen in the number of subspecies which have been described, rather than in genera. At the species level there are several endemics.

Curiously, the species and subspecies in the Caspian are generally of larger size than their relatives in the Black Sea basin. These observations are attributed to the variable environment in the Caspian Sea over time, with repeated changes in salinity and temperature which the fish could not avoid. Black, Mediterranean and Atlantic species lived under more stable conditions and could, in any case, retreat from lowered temperatures for example. In addition, the Caspian Sea clupeids lacked the competitors which entered the Black Sea from the Mediterranean and Atlantic and some (Clupeonella spp., Alosa caspia) could occupy the pelagic, planktivore niche taken up by other species in the Black Sea. There are no other pelagic fish but these herrings in the stable salinity areas of the Caspian Sea.

These fishes usually have modified scales on the belly forming abdominal scutes with a saw-like edge. Most species have 2, long, rod-like postcleithra. The lateral line is usually absent or on only a few scales. Silvery cycloid scales are easily detached and are found only on the body. The mouth is usually terminal with jaws about equal in length. Teeth are small or absent but gill rakers are long and numerous for sieving plankton. Fins lack spines and there are no barbels. There is no adipose fin. The pectoral and pelvic fins have a large axillary scale. The caudal fin is deeply forked. The eye is partly covered by an adipose eyelid. The flesh is particularly oily and is highly nutritional.

Members of this family often form immense schools in surface waters of the ocean and the Caspian Sea where they feed on plankton. Schooling is an anti-predator device making it difficult for a predator to pick out an individual from a tight mass of fish. There is also a "sentry effect" where awareness is increased by the presence of many fish. The school is maintained by a balance between visual attraction and lateral line stimulus repulsion. Herring can feed on the smaller plankton, less than 300-400 µm, at night by filter-feeding but during the day can also use particulate feeding. In the latter, they select larger plankton using the area temporalis, a specialised ventro-posterior region of the retina which improves vision as herring approach food items from slightly below.

Herring are easily caught and are extremely valuable to commercial fisheries. They are the most important fishes economically, both as food for man and also for many other commercial fish species. Wars have been fought over fisheries for herrings. In one year, members of the herring family made up 37.3% of all fish caught in the world. Some are used for fish meal, as fertiliser and as an oil source. The 1994-1995 catch of clupeids in the Iranian Caspian was 98.3 tonnes by beach seine and 671.5 t by gill nets, a decrease of 200 t in total over the previous year's catch (Iranian Fisheries Research and Training Organization Newsletter, 10:4-5, 1995)(but see later under Clupeonella where catch is much higher). The Caspian Sea shads account for about 35% of total inland production in Iran which was 117,300 t in 1995 (Bartley and Rana, 1998). These fish are used in a high value form as frozen whole consumer packs, as fish meal for poultry and in aquaculture, and in canning (Food and Agriculture Organization, Fisheries Department, 1996).

The catch of "sprats" (Clupeidae) in Azerbaijani waters is near extinction through poor fishery management according to Golub (1992).

Major sources for the biology and systematics of Caspian clupeids remains Svetovidov (1952), now inevitably dated but not yet updated, Whitehead (1985) and Hoestlandt (1991). There has been no recent, careful systematic and taxonomic study of these species in the Caspian Sea basin and extensive new material was not available for examination here.

Genus Alosa
Linck, 1790

The Caspian species of Alosa were formerly placed in the genus Caspialosa Berg, 1915. Svetovidov (1952) synonymised the genus Caspialosa Berg, 1915 with Alosa. There are 5 species in Iranian waters and the Caspian Sea as a whole but numerous subspecies have been described. Alosa species are also found in the Black Sea, Mediterranean Sea and Atlantic Ocean.

Often distinguished by gill raker counts which in any case overlap, the various subspecies are difficult to identify. Morphometric characters are of little help and Zamakhaev (1944) points out that some named taxa are merely different age groups. This problem is commented on further in the species accounts.

Caspialosa suworowi (Berg, 1913) (also spelt suvorovi in the literature) has been used for hybrids of various Caspian herrings and is not a valid species (Berg, 1948-1949). The holotype is in the Zoological Institute, St. Petersburg under ZISP 15927 (Svetovidov, 1952; Eschmeyer et al., 1996).

Alosa species are distinguished from sympatric Clupeonella species by larger size (up to 75 cm total length compared to 20 cm), a large mouth, a black spot on the flank behind the operculum and sometimes a row of such spots, an elongate scale or ala at the upper and lower base of the caudal fin, a notch at the mid-line of the upper jaw and by the last two anal fin rays not being elongated.

Caspian Sea species have a laterally compressed belly with 29-36 spiny scutes running from the throat to the anal fin; the dorsal fin origin is closer to the snout tip than the caudal fin base; the dorsal fin lies in a groove formed by enlarged scales; scales are easily detached; the pelvic fin origin lies below or slightly posterior to the dorsal fin origin; teeth are usually present on the jaws, roof of the mouth (on the palatine bone and always on the vomer bone), and on the tongue; the opercular bone is distinctly striated; eggs are demersal, semi-pelagic, and lack an oil globule; gill rakers highly variable in shape and number (18-180); dorsal fin branched rays 11-16, anal fin branched rays 10-21, scales in lateral series 49-60, and vertebrae 43-55.

Afraei Bandpyi et al. (2004) examined Alosa species from Mazandaran and Golestan provinces and found the following distinguishing characters:-

Species	Gill rakers	Ratio of eye diameter to total length (%)
A. braschnikowii	20-40, mean 30.9	2.9-5.8, mean 4.7
A. caspia	110-125, mean 118.3	5.7-7.5, mean 6.2
A. pontica	60-73, mean 66.8	4.3-6.5, mean 5.5
A. saposchnikowii	20-48, mean 32.8	6.0-9.3, mean 7.3

The general Farsi name for these fishes is shag mahi or zalun (both in Gilaki).

These herrings migrate from the north Caspian Sea to overwinter in the central and southern parts, returning north in the spring.

Alosa braschnikowii
(Borodin, 1904)

Common names

shagmahi, shagmahi-ye Khazari.

[dolkii siyanayn, Agraxan siyanayi, Sara siyanayi, irikoz siyanak, hasangulu siyanayi, agbas siyanak, all in Azerbaijan; Caspian marine shad, Kurinskaya sel'd or Kura herring, poloschataya sel'd or striped herring, Agrakhanskaya sel'd or Agrakhan herring, bol'sheglazaya sel'd or bigeye herring, dolginskaya sel'd or dolginka herring, belogolovaya sel'd or whitehead herring, Astrabadskaya sel'd or Astrabad herring, sel'd-gonets or driver, zheltospinka or yellow-back, Gasankulinskaya sel'd or Gasan-Kuli herring, kiselevichevskaya sel'd or Kiselevitch herring, Krasnovodskaya sel'd or Krasnovodsk herring, vostochnaya sel'd or eastern herring, obzhorka or glutton, Sarinskaya sel'd or Sara herring, maiskaya sel'd or May herring, Brashnikovskaya sel'd or Brashhnikov's shad, all in Russian].

Systematics

Originally described as Clupea caspio-pontica var. Braschnikowii. Reshetnikov et al. (1997) revert to the original double "i" ending to the specific name. A lectotype from Fort Shevchenko (Aleksandrovsk) is in the Zoological Institute, St. Petersburg (ZISP 13051) and paralectotypes were designated by Svetovidov (1952)(ZISP 13051). Clupea caspio-pontica is an unneeded new name according to Eschmeyer et al. (1996).

Alosa braschnikowii is regarded as a subspecies of Alosa caspia by some authors. Clupeonella leucocephala Berg, 1913 from Sumgait and Gyurgenchai, Azerbaijan is a synonym (as Caspialosa brashnikovi leucocephalia (sic) it is listed as a synonym of C. b. grimmi in Mikhailovskaya (1941)), as is Caspialosa caspia nigra Kisselevitsh, 1923 from the Caspian Sea opposite Dzambai (the material also included specimens of Alosa saposchnikowii) (Whitehead, 1985; Eschmeyer et al., 1996).

Alosa braschnikowii has 9 subspecies in the Caspian Sea (including Alosa curensis (q.v.) the Kura or striped herring), namely agrachanica (Mikhailovskaya, 1941) (author also spelt Mikhaylovsky or Mikhailovsky; dated 1940 in Eschmeyer et al. (1996) here and below but 1941 on the paper itself and in Svetovidov (1952) and Berg (1948-1949); species also spelt agrakhanika in Berg (1948-1949); Caspialosa brashnikovi morpha elata is a synonym according to Mikhailovskaya (1941)), the Agrakhan herring; autumnalis (Berg, 1915), the bigeye herring; braschnikowii (Borodin, 1904) (also spelt brashnikovi in Svetovidov (1952) and Berg (1948-1949)), the dolginka herring; grimmi (Borodin, 1904), the whitehead or Astrabad herring, driver or yellow-back; kisselevitshi (Bulgakov, 1926) (spelt kisselevitschi on the plate in Bulgakov (1926), kisselevitschi in Mikhailovskaya (1941), kisselevitshi in Svetovidov (1952) and Whitehead (1985) and kisselewitschi in Berg (1948-1949)), the Gasan-Kuli or Kiselevitch herring; nirchi (Morosov, 1928)(author also spelt Morosow in Mikhailovskaya (1941) and Morozov in Eschmeyer et al. (1996)) (with Caspialosa brashnikovi kenderlensis Budamshin, 1938 from Kendyrli Bay as a synonym in Svetovidov (1952) and Berg (1948-1949)), the Krasnovodsk herring; orientalis (Mikhailovskaya, 1941), the eastern herring or glutton; and sarensis (Mikhailovskaya, 1941), the Sara or May herring. Caspialosa brashnikovi derzhavini Tarasevich, 1946 described from the Caspian Sea near the Apsheron Peninsula, Azerbaijan may be another subspecies. Caspialosa kiselevitschi morpha elata Morozov, 1928 from the Caspian Sea, Krasnovodsk Bay, Turkmenistan is an infrasubspecific taxon and its availability and validity as a taxon have not been examined (Eschmeyer et al., 1996).

This high number of subspecies is an indication of the populational variation of this shad and not all subspecies may be valid. A modern revision is required to assess this problem. In light of this uncertainty and the lack of adequate sample sizes to determine which of the subspecies occurs in Iranian waters or which taxa are valid, reference is made here mostly to the species level. Additionally, it should be noted that hybrids between the various subspecies, and between this species and other species, do occur to complicate matters even further.

The neotype of Caspialosa brashnikovi agrachanica was designated by Svetovidov (1952) as the specimen described by Berg as Caspialosa brashnikovi m. elata taken in front of the Sulak River mouth, Agrakhan Bay and housed in the Zoological Institute. St. Petersburg under ZISP 7334.

The neotype of Caspialosa braschnikowi autumnalis was designated by Svetovidov (1952) as a specimen 26.9 cm long from the eastern shore of the Caspian Sea at Gasan-Kuli (just north of the Iranian border in Turkmenistan) caught on 8 April 1948 and housed under ZISP 31749.

The lectotype of Clupea curensis from the Kura River estuary is under ZISP 13984 with many paralectotypes as established by Svetovidov (1952) (Eschmeyer et al., 1996).

The neotype of Caspialosa kisselevitshi is also from Gasan-Kuli caught on 30 June-1 July 1926 and was housed in the Faculty of Zoology, Central-Asian State University (Sredne-Aziatskogo Gosudarstvennogo Universiteta), Tashkent.

The neotype of Clupea caspio-pontica var. grimmi was designated by Svetovidov (1952) as a specimen 34.0 cm long found at Ashur-ade (= Ashuradeh) near Astrabad Bay (= Gorgan Bay or Khalij-e Gorgan) on 23 April 1903 is under ZISP 13045.

The neotype of Caspialosa nirchi as designated by Svetovidov (1952) is from the southern part of the Caspian Sea opposite North Cheleken Spit and is under ZISP 31780.

The neotype of Caspialosa brashnikovi orientalis as designated by Svetovidov (1952) is from the southern part of the Caspian Sea opposite Kara-Ashly and is under ZISP 32187.

The neotype of Caspialosa brashnikovi sarensis from Sara Island is under ZISP 32184 as established by Svetovidov (1952).

Key characters

Characterised by a relatively elongate and rounded body likened to a "herring" shape, not as deep as in some related species which are likened to a "shad" shape. Total gill rakers 18-49 and short (about equal to gill filaments in length, sometimes shorter). Teeth are well developed in both jaws.

Morphology

Dorsal fin with 3-5 unbranched and 12-15, mostly 14, branched rays, anal fin with 2-4, usually 3, unbranched rays and 10-20, mostly 18, branched rays. Scales in lateral series 51-54. Teeth are well-developed on the jaws, tongue and roof of the mouth.

The accompanying table summarises characters of the subspecies and is taken from Svetovidov (1952) and Mikhailovskaya (1941) but identification to subspecies should be done with the keys from these works. Some of the characters used in the keys are not in the table as they do show individual variation and are difficult to summarise. An example is the nature of the gill raker (thin, thick, blunt, pointed, bent, straight, curved, branched, broken off, forked, swollen at the tip, etc.); another is the degree of protrusion of the lower jaw.

The subspecies grimmi is quite specialised in association with its benthic mode of life, feeding mostly on gobies (Gobiidae). It has a unique character in the well-developed callus on the tip of the lower jaw which adults acquire from rubbing the jaw on the sea bed while feeding, gill rakers are low in number as fine food is not taken, and the tips are broken off, broadened, and split owing to abrasion, and the rakers on the lower arch are reduced in number so the first raker is far from the tongue base. The subspecies nirchi is similar. In contrast, the subspecies kisselevitshi has a high gill raker count, rakers are pointed and not split at the tips, and the first raker is close to the tongue base. This species lives in surface waters feeding on Clupeonella, Atherina, shrimps, gammarids, and gobies (Gobiidae).

Character / Subspecies	Gill rakers (mostly)	Pectoral fins as % body length	Vertebrae	Head length as % of body length
agrachanica	20-46 (28-33)	13.1-15.6	47-54	22.6-25.2
autumnalis	21-37 (28-30)	16.4-19.9	45-53	26.0-29.2
braschnikowii	24-47 (30-33)	14.3-16.7	48-55	23.5-26.6
curensis	26-54	17.3-18.8	47-52	25.7-26.5
grimmi	18-28 (20-22)	12.9-15.2	45-52	22.9-26.4
kisselevitshi	29-49 (36-40)	13.9-16.8	43-53	24.2-26.9
nirchi	20-31 (23-26)	10.9-14.7	48-52	23.4-26.3
orientalis	20-35 (27-32)	13.5-18.0	45-53	25.0-27.8
sarensis	20-33 (24-27)	14.1-16.2	45-53	23.8-26.6

Sexual dimorphism

None reported.

Colour

The back and top of the head are dark with a green or blue tint and may be grey-green. Some subspecies are paler in colour with a grey or grass-green back and pale flanks, nirchi has a whitish blue-green head, light grey back with a slight greenish tint, and lower jaw and pectoral fins light, while grimmi is also quite pale with a grey-blue back and top of the head and whitish anterior head and pectoral fins. There is a dark spot behind the operculum but no series of spots along the flank in most subspecies, except in rare cases when there may be up to 7, occasionally 12-13. The subspecies grimmi regularly has a row of diffused, grey spots almost merging into a stripe, and nirchi occasionally. Pectoral fins are dark on some subspecies (braschnikowii, sarensis, kisselevitshi), pale or whitish on the others, although there is confusion in the literature over this, perhaps indicative of individual variation (cf. sarensis in Mikhailovskaya (1941)). The back and upper part of the head may become a deep black at spawning. The flanks and belly are silvery.

Size

Attains 50 cm standard length but average lengths are about 27-34 cm.

Distribution

All the Caspian subspecies are found widely distributed in the sea but chiefly in the south in winter, moving north to spawn in spring. The subspecies sarensis is reported from the Lenkoran coast and from southwest of Gasan-Kuli (in Turkmenistan just north of the Iranian border), the subspecies orientalis from Gorgan or Astrabad Bay, autumnalis from coastal waters at Gasan-Kuli, kisselevitshi from Astara and Gasan-Kuli, and grimmi from Astara and Gorgan Bay.

Zoogeography

This species is endemic to the Caspian Sea.

Habitat

In winter this species moves into deeper water towards the Iranian coast. In March it approaches coastal waters (Vetchanin, 1984) including brackish waters but does not enter fresh water. It never enters rivers in the south of the Caspian Sea (Jolodar and Abdoli, 2004). Salinities up to 47.6‰ are survived by this species. Spawning and feeding grounds are in the north Caspian for some populations but others live permanently in the south Caspian Sea and are of smaller size. The subspecies kisselevitshi, for example, lives off Gasan-Kuli in winter at depths below 25 m, not migrating or feeding. In March they move north to feed and then return south to spawn but lives almost entirely as a pelagic species in the southern Caspian Sea. Knipovich (1921) reports this species from depths of 80-98 m in Iranian waters. The density of this species increased from east to west in a 1999-2001 study in Iranian waters (Afraei, 2006).

Age and growth

Maturity is attained at age 2-5 and life span is up to 10 years, although this varies with the subspecies. Most south Caspian forms apparently mature at age 2 according to Svetovidov (1952). Growth rates also vary between subspecies, orientalis being one of the slowest growing herrings in the Caspian Sea and reaching 10 years of age. The catch near Astara of sarensis, for example, is mainly 4-5 year olds but this too varies with the subspecies and also with the year-class strength. Vetchanin (1992) reported on grimmi catches from the southeastern Caspian where the average length was 27.8-28.6 cm and the average weight 294-313 g. There is a tendency for length and weight to fall in catches as the summer progressed, from April to July. Length and weight are less in southern, compared to northern, waters. Afraei (2000) found this species to be the largest Alosa in Iranian waters on average at 395 mm and 760.3 g. Males predominate at 55.8% in Mazandaran and 69.4% in Golestan catches. Six age classes were present (1+ to 6+) with the 2+ class being the most common at 28.9% and 6+ the rarest at 8.9%.

Food

Diet in the southeastern Caspian Sea in winter comprises 85% Clupeonella engrauliformis with some gobies (Neogobius) and shrimps (Vetchanin, 1984). From March to November the diet is dominated by Clupeonella cultriventris, Atherina boyeri and shrimps. Juvenile Liza saliens, Syngnathus abaster, molluscs, crabs and higher aquatic plants are also recorded along with foreign objects such as rice husks, pieces of wood, foil, polyethylene, etc. This species is a cannibal. The more southerly populations examined favour Atherina boyeri and Neogobius species and some of these populations favour benthic invertebrates. The subspecies grimmi is the most benthic one and takes primarily gobies with some molluscs as well as Clupeonella. Feeding intensity rises sharply after spawning. While some herrings, like Alosa pontica, feed poorly on their migration, this species feeds intensively on its spring migration.

The feeding regime altered after the invasion of the ctenophore, Mnemiopsis leidyi. A shift was observed from 85% Clupeonella engrauliformis to 65% Atherina boyeri. Other fishes were also eaten including Clupeonella grimmi, C. cultriventris, Cyprinus carpio, Liza saliens, as well as Palaemon spp. (Iranian Fisheries Research Organization Newsletter, 49:2, 2006).

Reproduction

Vetchanin (1984) reports spawning of this species in the southeastern Caspian Sea north of Iranian waters to begin in early May, continuing to July as it is intermittent. The subspecies sarensis spawns along the Lenkoran coast from mid-April to the end of June. The subspecies orientalis spawns in Gorgan Bay from the end of March to the beginning of April, spawning schools forming at 17-18°C or higher. The subspecies autumnalis spawns at the same time off Gasan-Kuli near the Iranian border with Turkmenistan. The subspecies grimmi spawns in May-June in Gorgan Bay. The subspecies kisselevitshi has the latest spawning date, June to July and even in August off Gasan-Kuli when temperatures exceed 25°C. Spawning takes place in shallow water (1.8-5.8 m) in the sea over sand or silt bottoms at 15-18°C (some subspecies and populations at 20-22°C, others beginning as low as 11°C), and a salinity of 8-13‰. Fecundity is up to 178,400 eggs, average 66,000 per fish. There is no feeding while spawning. Early maturers, like the south Caspian populations, can reproduce up to 7 times in their life.

Parasites and predators

The Caspian seal, Pusa caspica, is a predator on this species (Krylov, 1984).

Economic importance

The catch for all species of "Caspialosa" in Iran varied between 5337 kg and 419,518 kg for the years 1956/1957 to 1961/1962 (Vladykov, 1964). In the Anzali region the catch for the years 1933/1934 to 1961/1962 varied from 1553 kg to 539,710 kg (Vladykov, 1964).

The catch has been as high as 126,900 centners or 12,690 t in the sea as a whole for the type subspecies alone (1 centner = 100 kg (Svetovidov, 1952)), taken chiefly in spring. Other subspecies were not fished for as extensively although kisselevitshi was the most numerous of the south Caspian forms of Alosa braschnikowii, forming 70% of the drift net catch.

Conservation

Reputedly depleted in Iranian waters. Kiabi et al. (1999) consider this species to be data deficient in the south Caspian Sea basin according to IUCN criteria. Criteria include medium numbers, medium range (25-75% of water bodies), absent in other water bodies in Iran, and present outside the Caspian Sea basin. Extinct in Turkey (Fricke et al., 2007).

Further work

The biology of this species in Iranian waters and the stocks or taxa found there need to be elucidated.

Sources

Iranian material: CMNFI 1970-0581, 5, 226.0-245.0 mm standard length, Gilan, Caspian Sea near Hasan Kiadeh (37º24'N, 49º58'E); CMNFI 1979-0431, 1, 297.2 mm standard length, Mazandaran, bazaar at Now Shahr (no other locality data); CMNFI 1980-0126, 1, 245.8 mm standard length Gilan, Caspian Sea near Bandar-e Anzali (37º28'N, 49º27'E); CMNFI 1980-0150, 1, 222.4 mm standard length, Gilan, Safid River estuary (37º24'N, 49º58'E).

Comparative material: BM(NH) 1938.8.2:1, 1, 245.9 mm standard length, Kazakhstan, Caspian Sea, Kaidak Bay (no other locality data); BM(NH) 1938.8.2:2, 1, ca. 337.5 mm standard length, Kazakhstan, Caspian Sea, Kaidak Bay (no other locality data); BM(NH) 1939.2.21:17-18, 2, 285.0-305.2 mm standard length, Caspian Sea (no other locality data); BM(NH) 1939.2.21:19-20, 2, 222.9-273.4 mm standard length, Caspian Sea (no other locality data).

Alosa caspia
(Eichwald, 1838)

Common names

shagmahi-ye shekambozorg (= big belly herring fish), shagmahi-ye chekameh dar, shagmahi-ye darya-ye khazar (= Caspian Sea herring fish), شاه ماهي (= shah mahi, meaning king fish), zalun (in Gilaki), puzanok.

[xazar sisgarini, sara sisgarini in Azerbaijan; Kaspiiskii puzanok or Caspian shad, severokaspiiskii puzanok or North Caspian shad, srednekaspiiskii puzanok or Central Caspian shad, il'mennyi puzanok or il'men shad, Enzeliiskii puzanok or Enzeli (= Anzali) shad, Sarinskii puzanok or Sara shad, Bakinskii puzanok or Baku shad, Astrabadskii puzanok or Astrabad shad, all in Russian].

Systematics

Clupea caspia was originally described in Latin from "Hab. in Caspio mari, meridiem versus" (Caspian Sea, towards the south).

A. caspia has 3 subspecies in the Caspian Sea basin, namely caspia (Eichwald, 1838) (= North Caspian, Central Caspian, Caspian or il'men shad); knipowitschi (Il'in, 1927) with natio knipowitschi (Il'in, 1927) (= Enzeli or Anzali shad) and natio saraica (Svetovidov, 1943) (= Sara or Baku shad); and persica (Il'in, 1927) (= Astrabad shad). The differences between natio knipowitschi and natio saraica are small (e.g. gill rakers 122-166 versus 140-150, both averaging 145; vertebrae 43-49 versus 45-51, both with mostly 47 or 48; growth differences are known, the former grows faster in the first 2 years of life but the latter reaches a greater size) and they probably have no taxonomic significance being simply separate breeding populations. The differences between Alosa caspia caspia natio caspia (the North or Central Caspian shad) and natio aestuarina Berg, 1932 (the il'men shad) were found to be based on geography and growth rate and these names have no taxonomic standing (Svetovidov, 1952). These natio are infrasubspecific ranks and have no validity as names.

Alosa rossica Kessler, 1870 described from the Volga River is a nomen nudum and is this species. Other taxa now considered as synonyms of Alosa caspia are Caspialosa caspia salina Svetovidov, 1936 from Mertvyi Kultuk and Kaidak bays in the northeast Caspian Sea and Caspialosa caspia kaidakensis Kazancheev, 1936 (spelt kajdakensis in Svetovidov (1952)) from Kaidak, the latter being in any case a synonym of the former subspecies. Clupeonella caspia m. elongata Berg, 1913 is also a synonym. Alosa caspica Yakovlev, 1871 is presumably a misspelling.

Knipovich (1921) records a species, Caspialosa enzeliensis Il'in, from the southern Caspian Sea which he places as a subspecies of caspia. I have been unable to locate the original description of this taxon, which presumably is found in the Anzali Mordab of Iran. It is probably an unused manuscript name for what Il'in later described as knipowitschi. As of 15 July 2007, this scientific name is a Googleblat for this page.

The lectotype of Caspialosa knipowitschi is a specimen 21.2 cm long from Anzali in Iran caught on 15 April 1915 and housed in the Zoological Institute, St. Petersburg (ZISP 31892). The lectotype of Caspialosa caspia var. persica is a specimen 147.5 mm long from the Caspian Sea Bay of Asterabad (= Gorgan Bay or Khalij-e Gorgan) north of Ashur-ade (= Ashuradeh) at 36°53'N, 53°55'E caught on 25 April 1904 on the Caspian Expedition of 1904 and housed in the Zoological Institute, St. Petersburg (ZISP 16413). The lectotype of Caspialosa caspia knipowitschi n. saraica is from near Sara Island and is under ZISP 32183. The lectotype of Caspialosa caspia salina is from Mertvyi Kultuk Bay, 10 km west of Cape Kizil-kair and is under ZISP 25813. These taxa were designated by Svetovidov (1952) as none were before or material was not preserved.

Key characters

Characterised by a relatively deep and compressed body likened to a "shad" shape, not as elongate and rounded as in some related species which are likened to a "herring" shape. Total gill rakers 50-180, variously reported as thin or thick, long (obviously longer than the gill filaments), and forming a convex outline on the lower arch. Teeth are poorly developed in both jaws.

Morphology

Dorsal fin with 3-4 unbranched and 12-15 branched rays, anal fin with 3-4, usually 3, unbranched and 15-20 branched rays. Scales in lateral series 49-54.

The characters distinguishing subspecies all overlap widely and are given below after Svetovidov (1952) and Hoestlandt (1991):-

Characters / Subspecies	Head length as % of body length	Pectoral length as % of body length	Vertebrae	Gill rakers
caspia	25.5-28.1	15.5-18.1	45-52 (49-51)	68-150 (100-140)
knipowitschi	18.3-24.1*	16.0-19.1	43-51 (47-48)	120-180 (130-160)
persica	25.6-27.1	16.5-17.7	45-51 (47-49)	50-120 (60-90)

* The numbers cited in Svetovidov (1952: 256 in the English version) and Hoestlandt (1991: 128) in the keys to subspecies do not agree with the numbers on p. 148 and p. 265 respectively in the species descriptions. The text numbers are used here.

Sexual dimorphism

Females are longer and weigh more than males of the same age.

Colour

The back is blue-green to dark and the flanks silvery. There is a black spot on the flank behind the upper operculum margin and sometimes up to 7 spots extending along the upper flank to a level of the rear of the dorsal fin.

Size

Reaches 28 cm standard length for caspia, to 29.6 cm for knipowitschi, and to 33.8 cm for persica.

Distribution

Found in the Caspian and Black seas. The subspecies caspia is found mostly in the western half of the Caspian Sea basin but is the most widely distributed subspecies, found throughout almost the whole sea. The subspecies knipowitschi is found in the south near Anzali, Astara and the Baku Archipelago, near the northern shore of the Apsheron Peninsula in autumn with a few reaching Gorgan lagoon in fall and winter; natio saraica is found north of Astara and spawns near Sara Island, natio knipowitschi spawns in the Anzali Mordab. The subspecies persica is found in the southeast, near Gorgan or Astrabad Bay. Holčík and Oláh (1992) report persica from the western basin of the Anzali Mordab (= Talab) and this species is reported from the Safid River and Anzali Talab as subspecies persica and from the Anzali Talab as knipowitschi (Abbasi et al., 1999).

Zoogeography

This species is part of a marine fauna encompassing the Black and Caspian seas, surviving in the reduced salinity of the latter.

Habitat

The type subspecies prefers open waters. Caspian shad winter at depths of 30-40 m or more and prefer temperatures not less than 8-11°C. They rise to surface waters in spring, moving north along the western shore of the Caspian Sea in waters of about 9-11°C according to Kushnarenko (1986) while Heckman in Hoestlandt (1991) states that this shad begins to migrate at the end of March at 5-6°C water temperature with a peak at 9-14°C in mid to late-April, ending in early May. Males migrate in large numbers at the beginning and end of the migration, females in the middle (Pushbarnek, 1987) while Heckman in Hoestlandt (1991) states that two waves of migration occur, one usually in late April at 7.6-10.2°C comprised of over 80% males and the second in the first half of May at 10.8-14.0°C comprised of over 70% females. The young, which hatch in the spring, leave the summer feeding grounds before the adults and migrate south before October-November. Adults follow as temperatures fall. Some populations do not migrate north and spend their whole life in the southern Caspian Sea. This subspecies will enter fresh waters to spawn in addition to spawning in the open Caspian Sea. The subspecies knipowitschia prefers water warmer than that of all other Caspian Sea clupeids except for Alosa caspia persica. Its sea movements are not well known but spawning fish favour waters with freshwater input and some fish enter rivers so it is classified as semi-anadromous. This subspecies was common in the Anzali Mordab but is now replaced by persica (Holčík and Oláh, 1992). It is also reported westwards to Astara and eastwards to Gorgan Bay. The winter habitat of persica is unknown. It is semi-anadromous and remains in the southern Caspian Sea near the shore. From spring to fall this subspecies moves northward along the eastern Caspian shore towards Krasnovodsk Bay and westwards to the Anzali Mordab.

Age and growth

Pushbarnek (1987) found shad of the type subspecies up to 7 years of age on the western coast of the middle Caspian Sea. In the spawning population, the predominant sizes and weighs for males were 16-21 cm and 60-130 g and for females 18-23 cm and 70-140 g. Males and females usually mature at 2-3 years although most spawn for the first time at 3 years. Females grow faster than males. Shad may spawn up to four times as the period of sexual maturation may continue for 2-5 years. The age composition of the spawning population is dependent on year-class strength. First spawners constitute 75.9% of 3-year-olds, 41.7% of 4-year-olds and 23.5% of 5-year-olds. The Caspian shad is a slow-growing species compared to A. braschnikowii and A. saposchnikowii, its mean length being 21.2 cm compared to 32.2 cm and 25.6 cm for the two other species respectively (Shubina, 1981). Dmitriev (1947) briefly examined the Anzali, Iran population and found 6 age groups but life span is noted by Heckman in Hoestlandt (1991) to be up to 9 years. Maturity is attained as early as 2 years although most fish appear to mature later as most spawners are 4-5 years old. The subspecies persica is the slowest growing of the shad species in the Caspian Sea, sexually mature fish being 13-21 cm long. Some fish become mature at 2 years of age. Life span is up to 8 years. The populations of both knipowitschi and persica are small compared to caspia. Abbasi and Sabkara (2004c) studied 180 fish from the southeast Caspian Sea coast of Iran and found fork length to be 103-232 mm, mean 158.8 mm, weight 16-130 g, mean 52.2 g and age 2-5 years, mean 2.64 years. Afraei (2000) found this species to be the smallest Alosa in Iranian waters on average at 110 mm and 109 g.

Food

The most intensive feeding period occurs after reproduction, beginning in June and the highest condition factor is found at the end of this summer feeding period. Little food is eaten in winter. Temperature (affecting metabolic rate) and zooplankton biomass (decreases engender competition with Clupeonella engrauliformis and other planktivores) are important factors governing catches of this species (Shubina, 1981). Food is chiefly copepods, more than 70%, with mysids at 20%, but some phytoplankton and small fishes are taken. Food in rivers after spawning is mostly cladocerans and other crustaceans. The above refers to the type subspecies; food of the other two subspecies is assumed to be similar. The southeast Caspian Sea fish studied by Abbasi and Sabkara (2004c) fed on phytoplankton (Rhizosolenia and Sprirogyra) at 4.5%, zooplankton (Foraminifera, Copepoda, Cirripedia, Bivalvia larvae) at 95.0%, and bony fish larvae and eggs at 0.5%. The presence of the ctenophore, Mnemiopsis leidyi, a food competitor reduced the index of fullness and fish growth was reduced.

Reproduction

Most spawning of the type subspecies occurs in the north Caspian Sea near the outflow of the major rivers, particularly the Volga, and the fish overwinter in the south Caspian, migrating between the two areas (Shubina, 1981). This subspecies spawns successively, 3 times within a week. Some fish enter fresh water to spawn. Spawning takes place at the favoured water temperature of 13.8-24.1°C, with mass spawning at 18-22°C, beginning as early as late April or as late as mid-May and continuing to mid- or late June. Most eggs are released in the upper 3 m of the water column. Fecundity reaches 41,000 eggs. The eggs are 1.11-1.38 mm when ripe but unfertilised and 1.92-2.91 mm in diameter when fertilised and are semi-pelagic to demersal. The subspecies knipowitschi spawns in the Anzali Mordab (and probably the "Chemkhala" River to the east of the Safid River) in May and June after a spring migration from the sea, leaving in the fall. Spawning of the subspecies persica takes place in Gorgan Bay and Holčík and Oláh (1992) suspect from catches of mature and spent fish that it also occurs in the Anzali Mordab.

Parasites and predators

The Caspian seal, Pusa caspica, is a predator on this species (Krylov, 1984) and it forms a substantial part of the diet of Silurus glanis in the Anzali Mordab (Holčík and Oláh, 1992). Naem et al. (2002) found the monogenean trematode Mazocraes alosae on the gills of this species in the western branch of the Safid River.

Economic importance

The type subspecies was the most important subspecies in the herring family in the Caspian Sea. It is caught off the coasts of Dagestan and Azerbaijan for research purposes and comprises 85% of the clupeid catch (Pushbarnek, 1987), 80-90% of the Caspian commercial catch (Kushnarenko, 1986). During the 1970s it was only 2% of the total Caspian fishery production. These herrings dominated the commercial catch in the Caspian Sea until the 1960s when commercial fishing was banned except on the western coast of the central Caspian. Many young of other commercial species were being killed in the herring fishery, entangled in the gill nets used. Soviet catches have weighed as much as 75,000 t. This fish is fattier than other Caspian Clupeidae, except for Alosa pontica kessleri, up to 18.1% of the body weight. The fat content decreases on the spring migration. The catch of the subspecies knipowitschi is of minor economic importance and had been little exploited when Svetovidov (1952) summarised biology, as the age of captured fish indicated. About 420 tons (sic, possibly tonnes) were caught in the Anzali Mordab in 1933 and 1934, but this may be an error in the report by Vladykov (1964) according to Holčík and Oláh (1992) although Berg (1948-1949) reports 4200 centners for the same period. The fishing season in the mordab began in mid-April and ended in mid-June when spent fish appeared. There appears to be no fishery data on the subspecies persica in the sea. Holčík and Oláh (1992) report catches of persica, which replaced knipowitschi, in the Anzali Mordab from the end of April to the beginning of June but in 1990 this comprised only 5 kg. It is regarded as of inferior quality in Iran. The Caspian shad is the dominant fish catch in the Iranian Caspian, comprising 51,000 t in 1994 rising from nothing a decade earlier (Food and Agriculture Organization, Fisheries Department, 1996). Robins et al. (1991) list this species as important to North Americans. Importance is based on its use as food.

Conservation

The stocks of this species in the Anzali Mordab are likely to increase as the lagoon becomes more saline (Holčík and Oláh, 1992). Kiabi et al. (1999) consider this species to be of least concern in the south Caspian Sea basin according to IUCN criteria. Criteria include abundant in numbers, widespread range (75% of water bodies), absent in other water bodies in Iran, and absent outside the Caspian Sea basin. Extinct in Turkey (Fricke et al., 2007).

Further work

The biology of this species in Iranian waters and the stocks or taxa found there need to be elucidated.

Sources

See under family heading.

Iranian material: CMNFI 1970-0524, 11, 58.7-88.9 mm standard length, Gilan, Caspian Sea at Bandar-e Anzali (37º28'N, 49º27'E); CMNFI 1970-0532, 1, 113.0 mm standard length, Gilan, Caspian Sea near Bandar-e Anzali (37º28'N, 49º27'E); CMNFI 1970-0543A, 1, 85.9 mm standard length, Gilan, Caspian Sea at Hasan Kiadeh (37º24'N, 49º58'E); CMNFI 1970-0586, 1, 77.5 mm standard length, Mazandaran, Gorgan Mordab at Ashuradeh-ye Kuchak (36º50'N, 53º56'E); CMNFI 1970-0587, 2, 107.4-108.6 mm standard length, Mazandaran, Babol Sar (36º43'N, 52º39'E); CMNFI 1971-0343, 1, 95.5 mm standard length, Gilan, Langarud at Chamkhaleh (37º13'N, 50º16'E); CMNFI 1979-0430, 1, 118.0 mm standard length, Mazandaran, river east of Now Shahr (36º39'N, 51º31'E); CMNFI 1979-0431, 7, 120.8-155.1 mm standard length, Mazandaran, Now Shahr bazaar (no other locality data); CMNFI 1979-0686, 2, 119.7-126.9 mm standard length, Gilan, Safid River (37º24'N, 49º58'E); CMNFI 1980-0146, 2, 106.9-171.8 mm standard length, Mazandaran, Gorgan Mordab at Ashuradeh-ye Kuchak (36º50'N, 53º56'E).

Comparative material: BM(NH) 1938.8.2:3, 1, 203.8 mm standard length, Caspian Sea (no other locality data); BM(NH) 1939.2.21:22-23, 2, 175.6-179.2 mm standard length, Caspian Sea (no other locality data); BM(NH) 1954.6.24:5-7, 3, 164.1-189.1 mm standard length, Caspian Sea (no other locality data).

Alosa curensis
(Suvorov, 1907)

This species is poorly known and not recorded from Iran but from Kyzylagach Bay of Azerbaijan. It may, in any case, be a subspecies or synonym of Alosa braschnikowii (see Svetovidov (1952) and the Alosa braschnikowii account herein).

Alosa pontica
(Eichwald, 1838)

Common names

shagmahi-ye poshtsiah, shagmahi darya-ye siah, shagmahi-ye moohajer or shagmahi-e-mohajer, zalun (in Gilaki), puzanok.

[Volga siyanayi, garabel siyanak in Azerbaijanian; arkasy gara takgas in Turkmenian; blackback, Caspian anadromous shad; chernospinka or black-spined herring, chernonosik or blacknose, beshenka, zalom, poluzalom, zheleznitsa, veselka, Volzhskaya mnogotychinkovaya sel'd or Volga many-rakered herring, Volzhskaya sel'd or Volga herring, Astrakhanskaya sel'd or Astrakhan herring, all in Russian; Pontic shad, Black Sea herring].

Systematics

Clupea pontica was originally described in Latin from "Hab. in Ponte Euxino prope Odessam" (= Black Sea near Odessa).

Alosa pontica has two subspecies in the Caspian Sea, namely kessleri (Grimm, 1887) (chernospinka or black-spined herring, chernonosik or blacknose, beshenka, zalom, poluzalom, zheleznitsa, veselka, blackback), and volgensis (Berg, 1913) (Volzhskaya mnogotychinkovaya sel'd or Volga many-rakered herring, Volzhskaya sel'd or Volga herring, Astrakhanskaya sel'd or Astrakhan herring, zheleznitsa, beshenka, veselka). The type subspecies is restricted to the Black Sea and its basin.

A lectotype of kessleri, 40.1 cm long, was designated from the Volga Delta by L. S. Berg under ZISP 15925 (in the Zoological Institute, St. Petersburg). A lectotype of volgensis, 34.8 cm long, is under ZISP 15926 and is from the Volga River at Chernyi Yar (Svetovidov, 1952).

Caspialosa volgensis bergi Tanasiichuk, 1938 described from the Volga Delta is a synonym of Alosa pontica kessleri (Heckman in Hoestlandt, 1991). Eschmeyer et al. (1996) give author and date for Alosa volgensis bergi as Tanassiychuk, 1940, the variation probably being due to transliteration of a Russian name and to year of actual publication rather than year on the journal.

Caspialosa kessleri infraspecies volgensis imitans Berg, 1948 from the Caspian Sea (see Berg (1948-1949) for further details) is not available because of its infrasubspecific rank (Eschmeyer et al., 1996).

Clupea caspio-pontica Borodin, 1904 is an unneeded new name for these fishes from the Black and Caspian seas (Eschmeyer et al., 1996).

Key characters

Characterised by a relatively elongate and rounded body likened to a "herring" shape, not as deep and compressed as in some related species which are likened to a "shad" shape. Total gill rakers 57-158 in the Caspian Sea, 57-95 in kessleri, 87-158 in volgensis. Rakers are usually longer than the gill filaments in volgensis, shorter in adult kessleri. Teeth are well developed in both jaws in kessleri and can be felt with a finger, poorly developed in volgensis such that they sometimes cannot be felt.

Morphology

Dorsal fin with 3-5 unbranched and 12-16 branched rays, anal fin with 2-4, usually 3, unbranched and 15-21 branched rays. Vertebrae 47-50 in kessleri (also a report of 50-54, both in Svetovidov (1952)), 48-54 in volgensis. Pyloric caeca 21-62. Scales in lateral series 53-56. Gill rakers in adults are thick and often broken off at the tip or near the base in kessleri, unbroken in volgensis. The tips of the gill rakers may be swollen and they are arranged in a straight line. Young fish have long and thin gill rakers with strong lateral spines. Spines are lost with age. Chromosome number is 2n=48 (Klinkhardt et al., 1995).

Sexual dimorphism

None reported.

Colour

The overall coloration is dark with a black back which has a violet tinge in spring in kessleri, light olive green in volgensis. There is dark, sometimes vague, spot on the flank behind the operculum and sometimes a series of spots in kessleri, but these are absent in volgensis. The pectoral fin is black on top. Spawning kessleri become grey or grey-green on the back and flanks with bronze spots on the operculum and flanks. A greenish-yellow circle forms around the eye after spawning.

Size

Reaches 52 cm total length and 2.0 kg for kessleri, 40 cm for volgensis.

Distribution

Found in the Black and Caspian seas and throughout the latter, entering northern rivers to spawn.

Zoogeography

This species is part of a marine fauna encompassing the Black and Caspian seas, surviving in the reduced salinity of the latter.

Habitat

Both subspecies are found in the open sea but kessleri ascends rivers much higher than volgensis which spawns in the delta region. Both subspecies overwinter in the southern Caspian Sea off the Iranian coast and then migrate north to enter the Volga and other northern rivers to spawn. The subspecies volgensis is absent from the southern Caspian in summer. The subspecies kessleri shows a greater affinity than volgensis for cold water.

The subspecies kessleri begins to migrate northward in March and April mostly along the western shore of the Caspian Sea, beginning to arrive in northern waters when temperatures are still below 5°C, most arriving when temperatures are 6-8°C compared to 10-13°C for volgensis. A mass migration into the lower Volga takes place in late April or early May for both subspecies when water temperature reaches 9°C and the peak run begins at 12-15°C, ending at 22°C. The run of volgensis is about 10 days later than that of kessleri and spawning takes place earlier as they do not travel as far upriver. Speed is up to 70 km/day for kessleri and depends on temperature. This fish used to run 2000 km up the Volga River. Sexually immature fish remain in the south and do not migrate. Knipovich (1921) reports kessleri as deep as 235-300 m in Iranian waters. Temperatures up to 25ºC are tolerated.

Age and growth

Males are sexually mature at 3 years and females at 4 years, other reports give 4-5 years for both sexes in kessleri. Many fish die after spawning but some survive to spawn two or three times. Four and five-year- olds dominate on kessleri spawning runs with some older fish also present. Females predominate in older fish making the spawning run. Life span is between 7 and 8 years.

Growth of the volgensis subspecies is slower than in kessleri, which apparently grows faster than any other Caspian clupeid. Life span in volgensis is 7-8 years with females living longer than males. Most spawners are 3-4 years old although in some years 5 year old fish are abundant. Males may mature at 2 years, females later. Most fish spawn again the next year after their first time but some may miss a year. An individual may spawn up to four times during its life.

Yılmaz and Polat (2002) compared scales, vertebrae, otoliths, opercles and subopercles as ageing structures and determined vertebrae to be the most accurate and reliable for a Turkish Black Sea population at Samsun. Six age classes were found.

Food

Cladocerans are the main food item of young kessleri which have a feeding peak at 1800-2200 hours and another at about 0800 hours. Adults in the sea take fishes such as Clupeonella and Atherina with some crustaceans and insect larvae. Clupeonella cultriventris makes up 92% of the diet of kessleri in the northern Caspian in May, with Sander lucioperca at 6.6% and gammarids at 1.0%. There is said to be little feeding on the spawning run although some fish sampled contained cladocerans, copepods, insects, bryozoans and fish fry.

The food of volgensis is similar to the other subspecies, taking copepods when young and larger items with growth. The main items are copepods, mysids, cumaceans, amphipods and small fishes. This subspecies feeds on the spawning migration.

Reproduction

Spawning in kessleri occurs in rivers from mid-May to mid-August, either the delta or lower reaches when entering in a ripe condition, or as much as 500 km upriver when entering in an unripe condition. Larger fish have spawning grounds further upriver than smaller fish and predominate earlier in the run. The spawning grounds in the Volga River cover a considerable stretch. Spawning usually occurs at 18-20°C between 0300 and 0600 hours or from 1600 hours to sunset. Spawning occurs in the main channel, over shallow sand banks, or in backwaters. Batches of eggs are laid at intervals of several days. Eggs are pelagic as in other Caspian Alosa and develop as they drift downriver near the bottom. At 22.7°C incubation takes about 40 hours. The young fish descend in late summer and early fall. Fecundity in kessleri reaches 344,000 eggs and egg diameter 1.51 mm. Shed eggs are up to 4.1m in diameter. Some fish may return to spawn in total three times.

Spawning of the first batch of eggs in volgensis may occur in the sea with the subsequent 2 batches at 7-10 day intervals in the delta and river. This takes place from mid-May to the beginning of August. Up to 281,000 eggs are shed. Peak spawning occurs at 15-19°C and ends at 25-27°C. Most spawning takes place in the evening between the 1600 and 2200 hours. The young appear in the pre-estuarine area of the Volga River in July and towards October begin to migrate south.

Parasites and predators

The Caspian seal, Pusa caspica, is a predator on this species (Krylov, 1984), larval shad are fed on by other fishes and by various invertebrates, and adults by various fishes and birds.

Economic importance

The subspecies kessleri and volgensis were caught on the spawning run with as much as 5750 t being taken annually pre-World War II. It is the biggest shad in the Caspian Sea. The subspecies kessleri was the most important and valuable herring in the Caspian Sea. Early spring catches were mostly kessleri but as the run of volgensis built up it formed an increasingly significant part of the catch, forming as much as 92% of the total. The catch of volgensis has declined from this period until the 1970s when the fish taken were mostly kessleri. The catch of Alosa pontica on the North Caspian fishing grounds in 1965-1972 has declined to 2-4% of the 1938-1943 catch. The subspecies volgensis was one of the most important Caspian herrings, 23-29% of the total catch from 1936-1939, as high as 69,100 t in 1939.

The subspecies kessleri is said to be the tastiest Caspian clupeid because of its high fat content, averaging 18.9% of weight along the coast of Azerbaijan, while in volgensis it was 9.6%. Post-spawners of kessleri may have a fat content as low as 0.5%. Catches are processed as canned, salted and pickled fish. Beach seines are used to catch this fish. Akhondzadeh Basteh et al. (2006) found the bacterial pathogen Vibrio haemolyticus in fresh and smoked Alosa kessleri (= pontica).

Robins et al. (1991) list this species as important to North Americans. Importance is based on its use as food.

Conservation

Stocks in Iranian waters are said to be depleted. The subspecies volgensis was in Category I on the "Red List" of the Russian Republic (Pavlov et al., 1985). Kiabi et al. (1999) consider this species (as A. kessleri) to be data deficient in the south Caspian Sea basin according to IUCN criteria. Criteria include commercial fishing, numbers unknown, range unknown absent in other water bodies in Iran, absent outside the Caspian Sea basin.

Further work

Stocks in Iranian waters need to be assessed and protected if required.

Sources

See under family account.

Iranian material: None available.

Comparative material: BM(NH) 1879.11.14:22-23, 2, 255.9-259.1 mm standard length, Caspian Sea (no other locality data); BM(NH) 1939.2.21:21, 1, 388.6 mm standard length, Caspian Sea (no other locality data).

Alosa saposchnikowii
(Grimm, 1887)

Common names

shagmahi-ye cheshmdorosht, shagmahi, kilka (incorrectly), herring.

[irikoz sisgarin in Azerbaijan; bol'sheglazyi puzanok or bigeye shad, Sapozhnikovskii puzanok or Saposhnikovi shad, all in Russian].

Systematics

The lectotype of Clupea saposchnikowii from the Volga Delta is in the Zoological Institute, St. Petersburg under ZISP 15921 (Berg, 1948-1949; Eschmeyer et al., 1996). The name is often spelt saposchnikovi, in error, or with a single terminal "i"; Reshetnikov et al. (1997) revert to the original spelling of the specific name.

Caspialosa caspia nigra Kisselevitsh, 1923, in part, from the Caspian Sea opposite Dzambai is a synonym with a lectotype in the Zoological Institute, St. Petersburg (ZISP 15938) (Kisselevitsh is also transliterated Kiselevich and Kisselevitz). The material also included specimens of Alosa braschnikowii (Whitehead, 1985; Eschmeyer et al., 1996).

Key characters

Characterised by a relatively deep and compressed body likened to a "shad" shape, not as elongate and rounded as in some related species which are likened to a "herring" shape. The upper and lower head profiles are straight. The upper edge of the lower jaw is straight. Total gill rakers 24-41, short (obviously shorter than the gill filaments), and thick. Teeth are well developed in both jaws.

Morphology

Dorsal fin with 3-5, usually 4, unbranched rays and 12-15, mostly 13, branched rays, anal fin with 2-4, usually 3, unbranched rays and 15-21, mostly 18, branched rays. Lateral series scales 52-55. Vertebrae 47-53. Pyloric caeca 36-59.

Sexual dimorphism

None reported.

Colour

Fish from the southern Caspian Sea are more intensively coloured than those from the north. The back is violet with green sheen, the flank has 4 dark stripes which merge with the dark on the back. There is a spot posterior to the operculum, which may be absent, and there is no series of spots.

Size

Reaches 36 cm total length and 650 g.

Distribution

Found mainly in the north Caspian Sea and the coast of Dagestan but entering Iranian waters

Zoogeography

This species is endemic to the Caspian Sea.

Habitat

This species spends its whole life in the Caspian Sea and never enters rivers. It favours colder water and is one of the first clupeid species to migrate north in spring, principally along the western coast. Large fish migrate first. Fish first approach the shore of Azerbaijan in mid-March with a mass approach from late March to mid-April. It is less frequently encountered in the southern part of the Caspian Sea, overwintering in the central Caspian and only moving south if winters are cold. A Caspian Sea Biodiversity Database (from www.caspianenvironment.org) has it at 400-600 m in the southern Caspian in cold winters but later states it keeps at 15-32 m. Winter temperatures at which this species is found are 6-7°C. Depths are 25-32 m in winter, more shallow in summer but below 9 m. Knipovich (1921) reports this species in a depth range of 52-77 m in Iranian waters. It tolerates a range of 3-25°C and spawns at salinities of 0.7-11.0‰, although preferring 4.0-7.5‰. The Caspian Sea Biodiversity Database (from www.caspianenvironment.org) estimates a population of 1.1125 billion fish.

Age and growth

Life span is about 9 years and female lengths and weights exceed those of males throughout life. On average, males weigh less than half the weight of females since females carry a heavy egg load. Growth is most intensive in the first two years of life and slows thereafter (Chang, 1972). Males mature at age 2 and females at age 3.

Food

A rapacious fish which takes young herrings and kilka, Atherina and even Benthophilus (Lönnberg, 1900b) as well as large crustaceans such as mysids and gammarids. It is a cannibal. This shad overwinters and feeds in the south Caspian Sea (Chang, 1972).

Reproduction

The spring spawning migration (end of April to end of May) enters the north Caspian Sea and fish are mostly 15-25 cm in body length. Males mature at a younger age than females as evidenced by fish 3-4 years old predominating among females and fish 2-4 years old among males in the north Caspian catch. Spawning takes place in May (peaking in the first 10 days) and most fish are returning for the second time. Spawning temperatures are lower than in Alosa caspia, being only 13-14°C although the peak is at 19-20°C. Spawning occurs in il'mens, the sea where there is a freshwater discharge such as near the Volga River mouth, and in the northeastern sea. Females may spawn up to 6 times and males up to 5 times (Chang, 1972). Spawning takes place in shallow water at 1-6 m depths. Fecundity is up to 318,852 eggs. The young migrate southwards.

Parasites and predators

The Caspian seal, Pusa caspica, is a predator on this species (Krylov, 1984).

Economic importance

An important commercial species in the central and northern Caspian, taken on their way to, and on, the spawning grounds. The fishery in Azerbaijan during 1937 caught fish on average 17 cm long and 62 g in weight, most fish being 2-3 years old. The Caspian catch in the period 1936-1939 reached a peak of 8,800 t annually. Fish are caught with beach seines, stationary nets and drift nets.

Conservation

Stocks in Iranian waters are reputed to be depleted. Kiabi et al. (1999) consider this species to be data deficient in the south Caspian Sea basin according to IUCN criteria. Criteria include numbers unknown, range unknown, absent in other water bodies in Iran, absent outside the Caspian Sea basin.

Further work

The biology of this species in Iranian waters and the stocks or taxa found there need to be elucidated.

Sources

See under family heading.

Iranian material: CMNFI 1970-0531, 15, 49.9-108.7 mm standard length, Mazandaran, Larim River (36º46'N, 52º58'E); CMNFI 1970-0532, 1, 137.4 mm standard length, Gilan, Caspian Sea near Bandar-e Anzali (37º28'N, 49º27'E); CMNFI 1970-0543A, 2, 78.8-80.2 mm standard length, Gilan, Caspian Sea at Hasan Kiadeh (37º24'N, 49º58'E); CMNFI 1970-0581, 1, 102.1 mm standard length, Gilan, Caspian Sea near Hasan Kiadeh (37º24'N, 49º58'E); CMNFI 1979-0788, 3, 96.0-114.9 mm standard length, Mazandaran at Khadje Nafas (37º00'N, 54º07'E); CMNFI 1980-0136, 3, 107.3-127.6 mm standard length, Mazandaran, Fereydun Kenar River (36º41'N, 52º29'E); CMNFI 1980-0157, 2, 96.6-101.1 mm standard length, Mazandaran, Gorgan River estuary (36º59'N, 53º59'30"E); CMNFI 1980-0908, 1, 77.9 mm standard length, Gilan, Safid River estuary (ca. 37º28'N, ca. 49º54'E).

Comparative material: BM(NH) 1954.6.24:8-10, 3, 150.5-177.0 mm standard length, Caspian Sea (no other locality data).

Alosa sphaerocephala
(Berg, 1913)

Common names

shagmahi-ye Agrakhan.

[kruglogolovyi puzanok or roundheaded shad, Agrakhanskii puzanok or Agrakhan shad, both in Russian].

Systematics

The holotype of Clupeonella sphaerocephala from Agrakhan Bay, at Tyulenii Island, Turali in the northern part of the Caspian Sea is in the Zoological Institute, St. Petersburg under ZISP 15928 with more than 30 paratypes (Eschmeyer et al., 1996).

Key characters

Characterised by a relatively deep and compressed body likened to a "shad" shape, not as elongate and rounded as in some related species which are likened to a "herring" shape. The upper and lower head profiles are obviously rounded. The upper edge of the lower jaw is crescent-shaped. Total gill rakers 25-45, long (equal to or longer than the gill filaments), and thin. Teeth are well developed in both jaws.

Morphology

Dorsal fin with 3-4, usually 4, unbranched rays and 13-15 branched rays, anal fin with 3-4, usually 3, unbranched rays and 17-20 branched rays. Vertebrae 47-51.

Sexual dimorphism

None reported.

Colour

The back is dark with an olive tint, the tip of the snout is occasionally black and the pectoral fins are dark. There is a black spot behind the operculum and occasionally a row of such spots.

Size

Reaches 25 cm.

Distribution

Found in the Caspian Sea including Iranian waters.

Zoogeography

This species is endemic to the Caspian Sea.

Habitat

This species does not enter fresh waters. It is most common along the eastern shore of the northern part of the sea in spring where spawning occurs and along the northern shore of the northern part of the sea in summer. Knipovich (1921) reports this species from Iranian waters in a depth range of 52-77 m.

Age and growth

Unknown.

Food

Unknown, although presumably similar to other shads.

Reproduction

Spawning takes place in the northeastern Caspian from mid-May to the end of June peaking at 18-20°C, most frequently in a salinity of 8-11‰ and in depths around 3-8 m. The young move south in late autumn, as late as November, the last clupeids to leave this area. Fecundity is about 20,000 eggs.

Parasites and predators

The Caspian seal, Pusa caspica, is a predator on this species (Krylov, 1984).

Economic importance

This species is caught only in small numbers.

Conservation

The status of this species is unknown.

Further work

This species is poorly known biologically and studies in Iranian waters should be carried out on its life history.

Sources

Iranian material: None available.

Comparative material: BM(NH) 1954.6.24:11-13, 3, 145.6-162.1 mm standard length, Caspian Sea (no other locality data).

Genus Clupeonella
Kessler, 1877

This genus is found in the Black and Caspian seas basins with 5 species, 3 of which are in the Caspian Sea and in Iranian waters.

Clupeonella species are distinguished from sympatric Alosa species by smaller size, a small and toothless mouth, adipose eyelids are small or rudimentary, no spots on the flank, no elongate scales (ala) at the base of the caudal fin, no vomerine teeth, the lack of a notch at the mid-line of the upper jaw, and by the last two anal fin rays being elongated.

Species in this genus live entirely in the sea, or in fresh water, or migrate between the two. Eggs are pelagic and have a large oil globule.

The general Farsi name for these fishes is كيلكا (= kilka or kelka, i.e. "sprat", although sprat is erroneous according to Berg (1948-1949) who uses tyulka for these fishes).

The three Clupeonella species have been fished in modern Iran since December 1971 but the commercial catch did not exceed 15,000 tonnes. Earlier catches date back only to 1939 with an annual catch of about 100 t in 1943-1949 exported in a marinated form to the Soviet Union (Alam, no date). Curiously, the abundance of kilka has long been known as Kinneir (1813) records "and herrings are in such abundance, that after a storm, the shores of Ghilan and Mazanderaun are nearly covered with them". Caddy (1984) refers to the kilka fisheries of the Iranian Caspian by the scientific name Sprattus sprattus but this is an error.

Caddy (1984) indicated that there were problems in marketing and utilizing these fishes in Iran even though up to 50,000 t could be caught annually (200,000 t elsewhere in the same article). Their best use was probably as food for predators such as Sander lucioperca, Esox lucius and Salmo trutta caspius. A study by Razavi Sayad (1993) suggested a ceiling of 100,000 t was possible. The Caspian Sea resources of kilka is estimated at 800,000 t from which 340,000 t can be exploited (Abzeeyan, Tehran, 6(8):IV, 1995).

The catch reached 51,000 t in 1994 from none 10 years previously (Food and Agriculture Organization, Fisheries Department, 1996) and was 36,000 t in 1997-1998 (IRNA, 31 March 1998) and 85,000 t in 1998-1999 (Fazli and Roohi, 2002). The catch for the first 6 months of the Iranian year was 17,000 t, taken by 70 trawlers and a 10% increase over the previous year (IRNA, 20 October 1998). Fishermen in Gilan caught 50,000 t annually in the late 1990s (Tehran Times, 5 September 1999). A reported catch of 56,000 t was made in 1999-2000, a 13% increase over the previous year (IRNA, 27 March 2000). A later estimate expects the kilka catch to reach 66,000 t by the year 2000 (Abzeeyan, Tehran, 5(9):IV, 1995). Fazli (2006a) records that kilka fishing ships discharge their catches at three ports, Babolsar and Amirabad in Mazandaran and Anzali in Gilan. The catch decreased from 28,000 t to 19,600 t in Mazandaran and from 57,000 to 42,600 t in Gilan from 1999 to 2000. The catch per unit effort also decreased from 3900 kg to 2500 kg over the two years. Anchovy kilka dominated the catch but the frequency fell from 85-90% to 76% of the catch and common kilka sharply increased. Common kilka had been caught in spring and summer but in 2000 they were taken in all months. The average length of anchovy kilka declined from 96.3 mm in 1997 to 87.3 mm in 2000 and this was also reflected in the age structure, 5+ and 6+ fish being rare. The presence of the ctenophore, Mnemiopsis leidyi, was thought to be damaging stocks (Fazli and Roohi, 2002). Darvishi et al. (200$) studied dietary overlap between the ctenophore and the anchovy kilka (see below). Fazli (no date) studied kilka catches off Mazandaran in 1996-2000. Fishing occurred at night and lasted 7.78-8.22 hours. The maximum catch at 42.8% was taken in October, November and December with a minimum catch in June. The least annual catch per vessel occurred in 1999-2000 (499,401 kg).

A study utilizing an echo-sounder and a pelagic trawler concludes that the maximum biomasses for the three Clupeonella species in the southern Caspian Sea are in winter (422,300 t) and autumn (326,900 t) while in summer and spring values are lower at 275,100 t and 260,800 t respectively. The population consists of 66.1% anchovy kilka (C. engrauliformis), 18.9% bigeye kilka (C. grimmi) and 15% common kilka (C. cultriventris) (Iranian Fisheries Research and Training Organization Newsletter, 14:6, 1996). Note that later, the Iranian Fisheries Research and Training Organization Newsletter (17:3, 1997) gives kilka biomass in the southern Caspian Sea as winter 22,300 t, autumn 26,900 t, summer 75,100 and spring 60,800 t, presumably lacking the initial digit, and the percentages of kilka species in the biomass are also wrong. This is corrected in a subsequent newsletter (Iranian Fisheries Research and Training Organization Newsletter, Tehran (18:43, 1997) but the corrected percentage biomasses are given as 66% for C. engrauliformis, 19% for C. cultriventris (as C. delicatula) and 15% for C. grimmi. It is unclear whether grimmi or cultriventris is the second most important kilka species. Pourgholam et al. (1996) give a stock assessment for kilkas in 1995-1995 using the hydro-acoustic method.

C. engrauliformis dominates the catch in Iran at 91.8%, followed by C. grimmi at 6.84% and by C. cultriventris at only 1.35%. The 2+ and 3+ year classes account for 69.95% of C. engrauliformis, 81.06% of C. grimmi and 80.88% of C. cultriventris catches. Catch rates of kilka on the top ranking 17 fishing grounds of 56 studied range from 800 to 1200 kg per unit effort per hour while traditional grounds have rates of 400-800 kg per unit effort per hour. The kilka are caught by attraction to lights and netting or pumping the catch into specially constructed ships. The kilka fishing fleet of Iran expanded in the 1980s and 1990s. There were 30 active vessels in Mazandaran in 1994, each with a capacity up to 30 tons (sic, probably tonnes here and elsewhere for modern catches) (Abzeeyan, Tehran, 4(10):IV, 1994). The Mazandaran Kilka Cooperative Companies Union had 75 boats in 2000 (Tehran Times, 31 December 2000). Gilan planned to construct 12 fish meal factories each with an annual capacity of 1000 t and 10 kilka canneries also with 1000 ton capacities (Abzeeyan, Tehran, 4(4):III, 1993). Catches off Gilan alone from April 1994 to January 1995 increased 59% compared to the same period in 1993-1994, exceeding 20,000 t (Abzeeyan, Tehran, 6(1):II, 1995). The catch off Mazandaran from March 1994 to March 1995 was 15,400 t, an increase of 10% over the previous year. About 1000 t were processed for human consumption and the rest for fishmeal production (Abzeeyan, Tehran, 6(2):V, 1995). The total kilka catch for Iran has increased to 45,000 t annually and efforts were being made to increase it to 110,000 t (Abzeeyan, Tehran 4(5):IV, 1993). The catch in 1995 was 32,000 t with 64.7% from Mazandaran and 35.3% from Gilan, with the maximum catch occurring in April (Abzeeyan, Tehran, 7(6):II, 1996). Catches declined from 95,000 t in 1999 to 15,497 t in 2003 (Sayyad Bourani et al., 2008). Annual Soviet catches reached 37,000 t in 1956 but this declined to 300-1500 t by the end of the 1970s or 0.2-0.8% of all kinds of tyulka or kilka in the Caspian Sea. Turkmenistan harvested 7660 and 8500 t in 1995 and 1996 although previously almost 45,000 t valued at $22.5 million had been taken before equipment deteriorated (http://bisnis.doc.gov/bisnis/isa/9805fish.htm, downloaded 14 March 2000). Stocks remain large even though kilka are heavily fished.

Kilka are smoked, salted, canned in sauce and oil and marinated according to a traditional recipe and seasoned with fruits, herbs and vegetables (Keivany and Nasrollahzadeh, 1990; www.netiran.com/business.html, downloaded 31 October 2003). Moini and Koochekain (2003) give details of fish sauce production from kilkas using traditional, microbial and enzymatic methods, along with taste tests. Vacuum packaging of fresh, smoked and salted kilka has been investigated in Iran (Annual Report, 1995-1996, Iranian Fisheries Research and Training Organization, Tehran, p. 45-46, 1997) and studies on processing kilkas as fish balls have also been carried out (Annual Report, 1994-1995, Iranian Fisheries Research and Training Organization, Tehran, p. 40, 1996). One company markets kilka in a clear package which gives the product a bright and colourful appearance. Kilka have even been made into crackers (Iranian Fisheries Research and Training Organization Newsletter, Tehran, 18:6, 1997; Shojaei, 1998). Kilka have also been made into oil as a by-product of the fish meal industry (Iranian Fisheries Research and Training Organization Newsletter, 27:3, 2001). M. Shivazad , H. John Mohammady, A. A. Yousef Hakimi and H. Fazaely (http://iman.ut.ac.ir/news/agr.htm, downloaded 12 December 2004) discuss the use of Clupeonella engauliformis as fish meal in animal nutrition and analyse the protein quality and Faeed et al. (2006) studied spoilage in kilka meal from bacteria and fungi. The Iranian Fisheries Research and Training Organization Newsletter (20:4, 1998) and Rezaei et al. (2003) report on methods of transporting kilka in cold water and crushed ice to processing factories which were better than traditional methods. Salmani et al. (2001) recommend chilled sea water for preservation for human consumption.

The kilka fisheries are threatened by the comb jelly, Mnemiopsis leidyi, which arrived in the Caspian in 1995 in the ballast water of ships and spread through the entire sea by the year 2000, feeding voraciously on zooplankton. It is now known as the "Caspian monster" despite its small size of 5 cm (Muir, 2001). It doubles in size in one day, reaches maturity in two weeks and then produces 8000 young each day (Muir, 2001). The fisheries collapsed by 50% in a few months, catches by one fisherman falling from being 3-6 t a night to half a tonne. Ghadirneja (2003) reports that C. engrauliformis originally dominated the kilka catch at 85-90% but has dropped to 55% through the impact of the comb jelly which has up to 2285 individuals per cubic metre in the southwest Caspian Sea. The fisheries may recover somewhat after the comb jelly population collapses (Tidwell, 2001b) or if a predator, Beroe ovata, is introduced and can survive in the less saline waters of the Caspian Sea (Muir, 2001). Studies indicate it can survive the brackish Caspian Sea water, feed on the comb jelly and not feed on other plankton (Iranian Fisheries Research Organization Newsletter, 36:35, 2003). The following catch records for the total kilka catch in Mazandaran in tonnes is courtesy of F. Darvishi (pers. comm., 2003) and shows the drastic decline caused by the ctenophore, as well as monthly variations in catches:-

Months/Years	1998 (1377)	1999 (1378)	2000 (1379)	2001 (1380)	2002 (1381)	Mean
March-April (Farvardin)	2848	2703	4644	1217	876	2458
April-May (Ordibehesht)	1116	607	972	1422	195	862
May-June (Khordad)	370	763	1819	125	158	647
June-July (Tir)	1392	919	194	425	444	675
July-August (Mordad)	2152	2306	433	614	249	1151
August-September (Shahrivar)	3117	2010	581	528	336	1314
September-October (Mehr)	3103	6184	1785	432	575	2416
October-November (Aban)	4120	3468	2305	3051	1196	2828
November-December (Azar)	3835	3410	2655	993	-	2723* (2179)
December-January (Dey)	2754	1735	620	1082	-	1548* (1238)
January-February (Bahman)	3968	1262	2146	1586	-	2241* (1792)
February-March (Esfand)	2815	1667	1192	1903	-	1894* (1515)
Total	31,590	28,034	19,648	13,378	4029

* = averaged over 4 and (5) years.

The species composition of kilkas changed after the introduction of the comb jelly comparing the year 2000 and before with the year 2002 - the common kilka changed from about 1-5% to about 30%, the bigeye from about 10-15% to 0/2% and the anchovy kilka from about 85-90% to about 70% (Iranian Fisheries Research Organization Newsletter, 36:2, 2003). The catch per unit effort (catch per vessel per fishing night) fell from 4 t to 1 t.

In 2004, more than 200 fishing boats had been forced to stop operations. The kilka stock has been reduced from 400,000 t to 80,000 t over the past 4 years and the catch fell by 34,000 t (www.iranmania.com, downloaded 4 October 2004). See also the section on the Caspian Sea basin in the Introduction. Mamedov (2006) gives details of the biology and decline of kilkas in Azerbaijan waters.

The Caspian seal was once a major predator on kilkas but the number of seals has declined on the Kazakhstan and Iranian coasts from 300,000 to 5000 in recent years through DDT pollution, viral infections and food shortages (Hashemi, 2001).

An account on the biology and identification of Caspian kilka in Farsi is given by Emadi (1991) and Fazli (1990), Fazli and Besharat (1998) and Poorgholam et al. (1996) give accounts of biology and catches in Iran in Farsi.

Clupeonella cultriventris
(Nordmann, 1840)

Common names

rizeh keraye (= tiny ?), rizeh kuli, kilka-ye ma'muli or kilka-e-maamooli (= common shad).

[xazar kilkasi in Azerbaijanian; adaty kulke balyk in Turkmenian; Kaspiiskaya tyul'ka or kil'ka (i.e. Caspian tyulka or kilka), tyulka, obyknovennaya tyul'ka (i.e. common tyulka), all in Russian; common kilka, common Caspian kilka, sardelle, Caspian sprat, Black Sea sprat].

Systematics

Clupea cultriventris was originally described from the northern shore of the Black Sea.

Clupea delicatula Nordmann, 1840, described from Odessa market on the Black Sea, is a synonym and a lectotype is in the Zoological Museum. St. Petersburg under ZISP 2254 with paralectotypes also under ZISP 2254, as designated by Svetovidov (1952). Clupeonella delicatula caspia Svetovidov, 1945 is a synonym described from the "Caspian Sea, where it is met with almost everywhere, from very saline parts (Kaydak Bay) to quite fresh. Enters the mouths of the Volga and the Ural rivers, ascending sometimes very far upstream". The holotype is from the Volga Delta and is under ZISP 15883 (Svetovidov, 1952). Kottelat and Freyhof (2007) consider this subspecies to be a a distinct species found in the Caspian Sea with cultriventris restricted to the Black Sea.

The Caspian Sea subspecies is Clupeonella cultriventris caspia (Svetovidov, 1941) described from the Volga delta and a lectotype, 152 mm long, was designated by Svetovidov (1952) in the Zoological Institute, St. Petersburg (ZISP 15883). Reshetnikov et al. (1997) consider recognition of this subspecies as questionable. Spelt cultiventris in some parts of Eschmeyer et al. (1996), apparently in error. Three syntypes of Clupea cultriventris may be in the Muséum National d'Histoire Naturelle, Paris under MNHN 3681 (Svetovidov, 1952; Eschmeyer et al., 1996).

Clupea cultriventris var. tscharchalensis Borodin, 1896 from Lake Charkhal in the Ural River basin is variously listed as a variety, morpha or a distinct species (see Svetovidov (1952) and Kottelat and Freyhof (2007)).

mtDNA studies of fish from Mazandaran and from Gilan showed statistically significant differences in haplotype frequencies, indicating genetically different populations (Laloei et al., 2006).

Key characters

This species has a moderately deep body (21-27% of standard length), a short and wide head (interorbital width 17.5% or more of head length), a sharply keeled belly, and pointed pectoral fin tips.

The Caspian subspecies is distinguished from the type subspecies of the Black Sea by having shorter pectoral (15.5-19.0% of standard length) and pelvic fins (8.5-12.5% of standard length), although ranges overlap, a shallower body, and a shallower and shorter head. It also grows faster and is more fatty than the Black Sea subspecies.

Morphology

The dorsal fin has 3-4 unbranched rays, usually 3, followed by 11-14 branched rays and the anal fin has 1-3 unbranched rays, usually 3, and 14-19 branched rays. Scales in lateral series 42-55. There are 24-30 belly scutes and 41-62 (rarely to 64), usually 51 or more, gill rakers. Vertebrae 40-44 (rarely to 45) compared to 44-47 in the anchovy kilka and 46-48 in the bigeye kilka, probably as a result of higher water temperatures during development compared to other kilka species (Prikhod'ko, 1979b).

Sexual dimorphism

Sexual dimorphism is only evident during egg development when the belly of females is swollen.

Colour

The back is blue-green or light-green, the flanks silvery and the belly silvery-white or golden-yellow. Fins are hyaline except the dorsal fin which has a central dark but faint stripe and the caudal fin which is darkish at the base. The iris is black.

Size

Reaches 14.5 cm standard length and 19 g.

Distribution

Found in the Black and Caspian seas, tributary rivers and some adjacent lakes. In Iran it is reported from sea and also the confluence of the Pasikhan and Pir Bazar rivers of the Anzali Mordab, the Anzali Mordab and its outlets by Holčík and Oláh (1992) and from the Safid River and Anzali Talab (= Mordab) by Abbasi et al. (1999).

Zoogeography

This species is part of a marine fauna encompassing the Black and Caspian seas, surviving in the reduced salinity of the latter.

Habitat

The habitat of this species in the Caspian Sea is the coastal zone of the sea at depths less than 100 m, more usually less than 50-70 m, over a wide range of temperatures (2.6-27.6°C for adults, higher for larvae, and possibly lower temperatures since they are found under ice and probably over 28°C according to some reports), and in fresh and hypersaline waters (to 36‰). The young can develop in water at 16‰. Southern populations live in a more saline habitat than northern and central Caspian populations which are mostly in fresh water. This tyulka may not migrate far but does move between summer-winter feeding and spring-early summer spawning grounds. Large schools are found 0.5-2.0 km from shore at depths of 20-25 m on the eastern coast of the Caspian Sea, descending deeper if water temperatures rise and coming up to about 8 m in autumn as temperatures fall. In winter this species is found at about 30-40 m deep where the temperature range is 7-10°C, warmer than surface waters. Larvae and young remain in shallow coastal areas. Knipovich (1921) reports a fish from a depth range of 235-300 m in Iranian waters but populations at these depths are small (Iranian Fisheries Research and Training Organization Newsletter, 14:6, 1996). The Caspian Sea Biodiversity Database (from www.caspianenvironment.org) states that the largest concentrations are found at 3-7‰ with most intensive spawning at 2-4‰.

It is the most widely distributed kilka and with the other kilka species the most abundant fish in the Caspian Sea (Prikhod'ko, 1979b). Large schools can be found by day but these disperse at night. It overwinters in the southern Caspian Sea and some individuals move north to spawn and feed in April. The Caspian Sea Biodiversity Database (from www.caspianenvironment.org) estimates the population to number 224 billion fish, with 96 billion fish in the south Caspian. The south and north Caspian Sea stocks are about equal in number after a decline in copepod biomass in the north. The relative frequency of this species compared to other kilkas increased after the invasion of Mnemiopsis leidyi, by more than 10% (Fazli, 2006b; Fazli et al., 2007).

Age and growth

The Caspian subspecies grows faster than the Black Sea subspecies. Together with the sturgeons, this species comprises 82.1% of the fish biomass in the Caspian Sea. Condition in this species is better in winter because of the summer-autumn feeding period after spring spawning compared to C. engrauliformis in the Big Kizil-Agach (= Bol'shoy Kyzylagach or Imeni Kirova) Bay of Azerbaijan (Badalov, 1972). Local populations have differing growth regimes depending on the productivity of these areas (Prikhod'ko, 1979b) and there are great variations on a yearly basis too. Southern populations grow faster than northern ones in their first year. Females grow somewhat faster than males (9.0 g versus 7.3 g average weight along the Dagestan coast for example), and life span is about 6 years. This species is mature there at 1 year and average life span is about 3 years.

Females dominate the population in Iran and sexual maturity is attained usually at age 2 and 2-4 year olds dominate catches but life span is up to 8 years (Iranian Fisheries Research and Training Organization Newsletter, 14:6, 1996; Abtahi et al., 2002). Fazli (2006b) found age classes 0+ to 5+ in Iranian waters with 0+ to 3+ making up 95% of the fish in 1997-1999. In 2000, age classes 0+ and 1+ were reduced in numbers and 2+ to 4+ fish comprised 93.8%. Abtahi and Taghavi (2006) examined fish from the conical net and light catch at Babolsar and found average fork lengths were 69.82 mm, 83.56 mm, 88.38 mm and 88.43 mm while weights were 2.2 g, 4.18 g, 4.77 g and 5.06 g for fishes at maturity stages I, II, II and IV. Fazli et al. (2007) studied this species from 1995 to 2004 in Iranian waters, sampled at landing sites at Amirabad and Babolsar in Mazandaran and Anzali in Gilan. Growth parameters were L_∞ = 132 mm, K = 0.259/yr. t₀ = -1.285/yr. The instantaneous coefficient of natural mortality was 0.506/yr, the instantaneous coefficient of total mortality (Z) was 1.62/yr and the instantaneous coefficient of fishing mortality varied over 10 years from 0.125/yr to 1.487/yr. Annual survival rate (S) was 0.200/yr. Age at first capture was 2.8 years. The von Bertalanffy growth equation was L_t = 132 (1-e^{-0.259(t +1.285)}). Ages ranged from 1 to 7 years with age groups 2, 3 and 4 dominating at different periods. Mean fork lengths were 59.3, 77.5, 87.4, 97.2, 104.5, 111.9 and 116.8 mm. Females dominated in each month except April, averaging 0.47:1, possibly due to differing attraction to lights used in the fishery. Biomass increased from 16,000 mt in 1995 to more than 41,000 mt in 2002, declining to less than 28,000 mt in 2004. The increase was simultaneous with a sharp decline in anchovy kilka, changes in zooplankton composition and abundance, and especially an increase in zooplankton species favoured by this kilka. Currently this kilka is overfished.

Food

Plankton is the main food and copepods predominate but diet also includes Cladocera, Balanus larvae and clam larvae. The dominant food item is the copepod Eurytemora grimmi, particularly in winter when plankton biomass is lowered in the Bol'shoy Kyzylagach Bay of Azerbaijan. The food of the common kilka is more varied than the other kilka species simply because of its habitat in shallow coastal areas (Badalov, 1972; Prikhod'ko, 1979b). Older fish take larger and faster crustaceans and consume less food in proportion to body size as they grow. The most intensive feeding is in summer and autumn, decreasing in winter and during reproduction. Food is taken during the day.

Reproduction

Spawning occurs in January-February in the southern Caspian, later in the north, mainly in depths less than 10 m and where salinity is low to average for the Caspian Sea (Badalov, 1972; Prikhod'ko, 1979b). The largest southern Caspian population spawns near the mouths of the Volga and Ural rivers (Kozlovsky in Hoestlandt, 1991). Spawning is most intensive at 11°C, but occurs at 10-20°C. Spawning is intermittent and lasts from mid-April to July. Peak spawning in Iranian waters of Mazandaran Province is April-May with an average fecundity of 28,240 eggs (Abtahi et al., 2002). Fazli (2006b) recorded mass spawning in Iranian waters in April, continuing on until August. Eggs are released in water 0.5-9.0 m deep at a salinity range of 0.02-15‰, perhaps as high as 29.15‰. Fecundity reaches 60,000 eggs and egg diameter 1 mm, 0.48-1.46 mm for fertilised eggs. Relative fertility is 4-13 times greater than in Alosa species. Holčík and Oláh (1992) consider that it may spawn in rivers entering the Anzali Mordab. The study of Fazli et al. (2007) showed that reproduction started in March, peaked in May and finished at the end of August. Half the females were mature at 84.3 mm fork length.

Parasites and predators

Samples of this species from Babol Sar and Bandar Anzali contain the digenean parasites Pseudopentagramma symmetrica and Bunocotyle cingulata, the acanthocephalan Corynosoma strumosum, metacercariae of a Bucephalus species, and larvae of a Contracaecum and an Anisakis species (Iranian Fisheries Research and Training Organization Newsletter, 11:4-5, 1996; Annual Report, 1995-1996, Iranian Fisheries Research and Training Organization, Tehran, p. 28, 1997; Shamsi and Dalimi, 1996; Shamsi et al., 1998).

Clupeonella species are an important food fish for sturgeons (59.4% by weight of Acipenser stellatus diet in the Middle Caspian), Sander, herrings (Clupeidae) and the Caspian seal (Badalov, 1972; Krylov, 1984) as well as Salmo trutta caspius and Stenodus leucichthys (Kosarev and Yablonskaya, 1994).

Economic importance

It is caught by attraction to underwater electrical lights (Prikhod'ko, 1979b). The other subspecies is also of major importance in the Sea of Azov. The Caspian subspecies is caught in school seines in spring and purse seines in summer. In Iranian waters this species formed only a small proportion (1.35%) of the total kilka catch in a study by Razavi Sayad (1993) and Fazli (2006b) gives values of 1.34%, 2.5% and 5.5% for the years 1990-91, 1997-98 and 1998-99 respectively. However, as the anchovy kilka catch declined, this species increased from 13.7% of the total catch in 1999 to 48.9% in 2003 (Sayyad Bourani et al., 2008).

Robins et al. (1991) list this species as important to North Americans. Importance is based on its use as food and as bait.

Conservation

Stocks on the Iranian coast are said to have been depleted but its ecological specialisation on zooplankton means there is comparatively little competition with other fishes. It is probably not in any immediate danger. Kiabi et al. (1999) consider this species to be of least concern in the south Caspian Sea basin according to IUCN criteria. Criteria include commercial fishing, abundant in numbers, widespread range (75% of water bodies), absent in other water bodies in Iran, and present outside the Caspian Sea basin.

Further work

The biology of this species in Iranian waters needs to be elucidated.

Sources

Counts are based in part on Svetovidov (1945a). See also under family heading.

Iranian material: CMNFI 1970-0531, 14, 78.0-88.6 mm standard length, Mazandaran, Larim River (36º46'N, 52º58'E); CMNFI 1980-0146, 7, 79.9-96.2 mm standard length, Mazandaran, Gorgan Bay at Ashuradeh-ye Kuchak (36º50'N, 53º56'E); CMNFI 1993-0146, 3, 80.2-98.2 mm standard length, Mazandaran, Gorgan Bay (no other locality data); CMNFI 1993-0167, 1, 96.6 mm standard length, Mazandaran, Caspian Sea, 10 km offshore (ca. 36º49'N, ca. 52º39'E); CMNFI 1993-0168, 3, 84.9-88.0 mm standard length, Mazandaran, Caspian Sea, 10 km offshore (ca. 36º49'N, ca. 52º39'E).

Clupeonella engrauliformis
(Borodin, 1904)

Common names

rizeh keraye (= tiny ?), kilka-ye anchovy or kilka-e-anchovi.

[ancousabanzar kilka in Azerbaijanian; ancous sekilli kulke balyk in Turkmenian; anchousovidnaya tyul'ka or anchovy-like tyulka, sardelle or sardel'ka, "sardinka" but incorrectly, all in Russian; anchovy kilka, anchovy sprat].

Systematics

No major synonyms. Originally described from Buinak, central part of the Caspian Sea. The lectotype is in the Zoological Institute, St. Petersburg (ZISP 13860) with paralectotypes as established by Svetovidov (1952) (Eschmeyer et al., 1996). Eschmeyer et al. (1996) give the date as 1906 but Reshetnikov et al. (1997) give 1904.

Key characters

This species has a slender body (16-19% of standard length), a short and wide head (interorbital width 16-18.5% of head length), a rounded belly, and pointed pectoral fin tips.

Morphology

Dorsal fin with 3 unbranched and 12-14 branched rays, anal fin with 3 unbranched and 15-19 branched rays. Scales in lateral series 45-49. Vertebrae 44-47, rarely to 48 compared to 41-44 in the common kilka (C. cultriventris). Gill rakers number 56-67. Belly scutes 23-31.

Sexual dimorphism

None reported.

Colour

The back and head are dark blue with violet, green or olive tints. These colours become brighter or turn black in dead fish. The fins are hyaline except the caudal fin which has a black base and the dorsal fin which has a central dark stripe.

Size

Attains 15.5 cm standard length.

Distribution

Found in the central and southern Caspian Sea, and in Iranian waters the southeast Caspian Sea, southwest Caspian Sea and the south-central Caspian Sea (Kiabi et al., 1999) as well as the Anzali Mordab and Gorgan Bay (Armantrout, 1980).

Zoogeography

This species is endemic to the Caspian Sea.

Habitat

The anchovy kilka, along with other kilkas, is the most abundant fish in the Caspian Sea forming large concentrations in the central and southern Caspian wherever water depth exceeds 30 m. The anchovy kilka is estimated to be the most numerous kilka at about 77% (Ivanov and Katunin, 2001; Daskalov and Mamedov, 2007). It is generally found in the upper water layers but may descend to 120 m. Nearshore areas, inlets and water of a salinity below 8‰ are avoided. They can tolerate a salinity range of 8-14‰ but the main part of the population is found at 10-12‰ (Fazli et al., 2007). Overwintering takes place in the southern Caspian and the southern part of the central Caspian Sea at 8.5-9.0°C and up to 13.5°C. Schools extend their range into the central and northern Caspian in spring to feed (Prikhod'ko, 1979b). This species has a hibernation period in the south Caspian Sea, a spring migration of part of the population to the central Caspian, a feeding period in the central and south Caspian and an autumn prespawning migration to the south Caspian (Sedov and Rychagova, 1983).

In Iran larvae are found mostly in surface layers at 5-20 m while adults are found in deeper zones. males dominate in winter while females dominate in other seasons. The maximum juvenile density (fish <75 mm), comprising 36% of the population, is seen in the summer (Iranian Fisheries Research and Training Organization Newsletter, 20:7, 1998). Jolodar and Abdoli (2004) state it is most abundant at 100-150 m.

Age and growth

Abundance of young anchovy kilka, and hence future year-class strengths, depends on water temperature in autumn (October-November). Falling water temperatures, in the eastern Caspian for example, are caused by upwelling which brings nutrients to surface waters and promotes growth of plankton on which the kilka larvae feed (Prikhod'ko, 1979a). Females are somewhat larger than males in the spawning areas. Sexual maturity is attained usually at age 2 and 2-4 year olds dominate catches but life span is up to 8 years (Iranian Fisheries Research and Training Organization Newsletter, 14:6, 1996). This species shows the fastest rate of growth in the genus. Of the 8 age classes, 0+, 1+, 2+ and 3+ form 99.91% of the whole population (Iranian Fisheries Research and Training Organization Newsletter, 20:7, 1998). The same study showed that 18.6% of the population matures in the first year of life while 81% matures in the second. The mean age in coastal areas is 2.9 years, slightly higher than that in deep zones below 200 m where 0+ fish are more abundant. The Caspian Sea Biodiversity Database (from www.caspianenvironment.org) gives a population of up to 293 billion fish in the Caspian Sea.

Fazli et al. (2007) and Sayyad Bourani et al. (2008) studied these kilkas from catches with conical liftnets carrying underwater lights in the fisheries of Gilan and Mazandaran in the 1995-2004 period. Fish were aged using the sagittal otoliths. Length and weight ranges were 40-140 mm and 0.4-18.4 g with averages of 94.0 mm and 5.7 g (89.2-100.4 mm from 1999 to 2003 in Sayyad Bourani et al., 2008). The age range was 1-7 years. The dominant age group varied from age 2 to age 4, making up 40.6% to 57.7% of the catch (Fazli et al., 2007) or 5+ years with 4+-5+ making up 84.6% for 1999-2003 (Sayyad Bourani et al., 2008). Growth was high for the first year of life and then gradually decreased. The von Bertalanffy growth equation was L_t = 148(1-e^{-0.238(t+1.340)}) (Fazli et al., 2007, and following data). The sex ratio varied with season and was significantly different from equal at male:female = 0.78:1 for adults. Females were more abundant from January to June and males predominated from September to November. Condition factors differed significantly between years, increasing from 1995 to 1996, being lowest in 1998 and then increasing to 2004, and between months, being lowest in January and February and then increasing in March. 50% of fish were mature at 84.5 mm fork length. Annual survival rate was estimated at 0.32, the instantaneous coefficient of total mortality (Z) was 1.14/year, natural mortality was 0.473/year. Age at first capture was estimated as 2.92 years. The total biomass declined from 186,000 t in 1996 to less than 12,000 t in 2004 and the exploitation rate for 1995-2004 varied between 0.340 and 0.815. Sayyad Bourani et al. (2008) give a K value of 0.598/year and a L_∞ of 110.13 mm. Natural, fishing and total mortality coefficients were 0.69, 0.31 and 1 per year respectively and the sex ratio was female:male = 68.2-31.8. These latter results for the 1999-2003 period show how value scan change when subsets of data are used.

Food

Plankton is the main food and copepods predominate but diet also includes Cladocera, Balanus larvae and clam larvae. The dominant food item is the copepod Eurytemora grimmi, particularly in winter when plankton biomass is lowered (Badalov, 1972). It can make up over 70% of its food. This copepod is more characteristic of the diet of this kilka compared to the other two species and the daily vertical migrations and seasonal movements of the copepod are mirrored by the kilka. The most abundant fish species in the Caspian depends on the most abundant member of the crustacean zooplankton (Prikhod'ko, 1979b). This species feeds in winter, unlike Clupeonella cultriventris. Bankehsaz (1996) surveys the fluctuation in fat content of this species through the year. Intensive feeding begins in spring as a preparation for spawning (Sedov and Rychagova, 1983). Spawning males show a positive response to light and so feed during the spawning season, while females do not. F. Darvishi (pers. comm., 2003) has demonstrated that the this species has a similar feeding niche as the exotic ctenophore Mnemiopsis leidyi and Esmaili Sari et al. (2002) determined that there is a similar diet in Iranian waters suggesting that a decline in stocks of the fish is the result of competition. Darvishi et al. (2004) studied catches of the anchovy kilka and the ctenophore in the southern Caspian Sea from August 2001 to October 2002. Dietary overlap was >89 in Babolsar samples and >84 in Nowshahr samples using the Schoener Index (presumably 0.89 and 0.84 where 0 is no dietary overlap and 1 is an identical diet). The ctenophore was also feeding on fish eggs but the effect of this was less than competition for food.

Reproduction