Genus Schizothorax
Heckel, 1838

The snow trouts, mountain barbels or Indian trouts are found from Iran to China, favouring mountainous areas but occasionally in lowlands. There are about 56 species (more if some other genera are included), with 3 in Iran.

The genera Racoma McClelland and Griffith in McClelland, 1842 and Aspiostoma Nikol'skii, 1897 are synonyms of Schizothorax Heckel, 1838 (Eschmeyer, 1990).

Schizothorax intermedius, and other species, have been placed in the genus Schizothoraichthys Misra, 1962 (e.g. in Tilak (1987). However Schizothoraichthys is regarded as a synonym of Schizopyge Heckel, 1847 by Jayaram (1981) or of Schizothorax (see Talwar, 1978; Eschmeyer, 1990). Schizopyge is itself regarded as a synonym of Schizothorax by some authors, e.g. Talwar (1978). Talwar (1978) separates the genus Oreinus McClelland, 1839 from Schizothorax by the margin of the lower jaw having a firm and hard horny covering which is thickest internally and a thick lower lip with a free posterior edge forming a sucker. Schizothorax has a non-suctorial lower lip and a lower labial fold interrupted or entire in the middle. However Talwar and Jhingran (1991) contradict this view and use Schizothoraichthys for Schizothorax and Schizothorax for Oreinus. Tilak (1987) recognises the name Schizothorax for fishes with strip of papillated tissue on the chin and Oreinus as a synonym; Schizothoraichthys is used then for fishes without the papillated chin. Oreinus is regarded as a synonym of Schizothorax by Jayaram (1981) and Eschmeyer (1990). Mirza (1991a; 1991b) recognises a tribe Schizothoracini, with the genera Schizothorax, Schizopyge, Racoma McClelland (and Schizocypris). I have retained Schizothorax here as the oldest name in view of these conflicting opinions.

There are various records of nominal Schizothorax species from the Helmand River basin in Afghanistan summarised in Coad (1981d); they have not been reported from the Sistan lowlands of Iran.

This genus is characterised by an elongate and almost cylindrical body, very small scales, over 100 in the series next to the lateral line, scales in complete lateral line somewhat larger, the vent and anal fin base are sheathed in enlarged scales and there may be enlarged scales near the pectoral fin and edge of the gill opening, dorsal and anal fins are short, dorsal fin with a thickened last unbranched ray bearing denticles (denticles lost with age), pharyngeal teeth in 3 rows and hooked at the tip, 4 barbels (rostral and maxillary), mouth inferior or subterminal, lower jaw may have a horny sheath, a papillated area on the chin may be present or absent, the lower labial fold may be interrupted or not in the middle, elongate gut and black peritoneum, and poisonous eggs. Members of the Schizothoracinae tribe are of polyploid origin with 2n=98 and 3n=148.

The ancestors of the schizothoracines in general were barbinines in the eastern part of the Qinghai-Xizang Plateau as it rose and water temperatures decreased in the late Miocene to early Pliocene (Sizhong, 1995). Primitive genera like Schizothorax migrated westwards earlier and further than more specialised genera such as Schizopygopsis (although both reach their westernmost distribution in Iran).

These fishes generally prefer rapids and pools of the larger streams at temperatures of 8-22°C although some occur in lakes with inflowing streams (Sharma, 1988). They are found in streams above 3000 m. Food varies from detritus to insects, plankton and fish depending on the species. The spawning season may be in late summer and early fall or in spring. Egg counts vary from a few hundred to over 50,000 and egg diameters may attain 3.6 mm. Some species show a spawning migration from warm lakes to cold streams.

Deaths have occurred from eating poisonous eggs of members of this genus but none are reported from Iran (see under S. zarudnyi). Symptoms include abdominal pain, nausea, vomiting, diarrhoea, dizziness, headache, fever, bitter taste, dryness of the mouth, intense thirst, sensation of chest constriction, cold sweats, rapid irregular weak pulse, low blood pressure, cyanosis, pupillary dilatation, syncope, chills, dysphagia and tinnitus. Severe cases show muscular cramps, paralysis, convulsions, coma, and death. Victims generally recover within 3-5 days with supportive treatment but it may take longer. Treatment is symptomatic and there is no known antidote or therapeutic data available. The patients' stomach should be evacuated as soon as possible after ingestion of eggs (Halstead, 1967-1970; Coad 1979b). Fish eaten during the breeding season should be cleaned with care to remove all traces of the eggs to avoid contamination of the flesh as cooking does not destroy the toxin.

Schizothorax esocinus
(Heckel, 1838)

Reported from the Helmand River drainage of Afghanistan; records summarised in Coad (1981d). No Iranian record.

Schizothorax intermedius
McClelland, 1842

Common names

mawda (in Sistan), marinka.

[marinka obyknovennaya or common marinka in Russian.

Systematics

Schizothorax intermedius was described from the "Cabul river at Jullalabad. Tarnuck River" in the Indus River basin.

Oreinus plagiostomus McClelland, 1842 described from the "Helmund river at Girdun Dewar" in Afghanistan, Racoma brevis McClelland, 1842 described from the "Helmund River", Racoma labiatus McClelland, 1842 described from "Pushut, Koonar river near Jullalabad" in the Indus River basin but also reported from the Helmand River basin by Annandale and Hora (1920) and Schizothorax ritchieana McClelland, 1842 described from "Affghanistan. In the Helmund there is a variety of this species ..... which will probably prove to be distinct." are probably synonyms (Berg, 1949).

Schizothorax schumacheri Fowler and Steinitz, 1956 described from "Zabol, Eastern Iran" is also a synonym (Saadati, 1977). The holotype of Schizothorax schumacheri (ANSP 71950) at 244 mm total length and a paratype (ANSP 71951) at 130 mm to the end of the broken caudal fin, are stored in the Academy of Natural Sciences of Philadelphia (Böhlke, 1984).

Kähsbauer (1964) reports a hybrid between Schizothorax schumacheri and Schizopygopsis stoliczkae from Sistan which may in fact be Schizocypris altidorsalis.

Tilak (1987) reports Schizothorax richardsonii (Gray, 1832) from Sistan based on 2 fish in the Zoological Survey of India, Calcutta (F. 1226-1227/1), which I have not seen, and this may be the correct name for this fish.

Key characters

Gill raker counts and distribution separate this Schizothorax from others in Iran.

Morphology

This is a very variable species, depending on habitat (Mirzaev, 1998). Dorsal fin with 2-4 unbranched and 5-9, usually 8 (Kullander et al. (1999) give 6-7 for their Kashmir specimens of S. curvifrons), branched rays, anal fin with 1-3 unbranched and 4-7, usually 5, branched rays, pectoral fin branched rays 14-19 and pelvic fin branched rays 7-10, usually 8. Lateral line scales 85-121, scale series next to the lateral line 115-165. Pharyngeal teeth 2,3,5-5,3,2. Gill rakers 10-17 (Kullander et al. (1999) give 21-28 for their Kashmir specimens of S. curvifrons). Total vertebrae 48 (Howes, 1987) or 40-43  (2000a) – presumably excluding 4 Weberian vertebrae). There is considerable variation in lower jaw form in specimens attributed to this species. The lower jaw may be crescent-shaped with or without a sharp horny sheath, or covered with a deciduous horny layer, or transverse and covered by a horny sheath. Lips may be interrupted medially or continuous, and can be very strongly developed. The dorsal fin spine may be well-developed with numerous denticles or weakly-developed with denticles not beyond the middle of the spine. Various morpha or infraspecies have been described to refer to these forms (see Berg, 1948-1949). Barbel length is highly variable. Young about 30 mm long have a naked body and no barbels. The karyotype is 2n=98-100.

Usually silvery and occasionally with minute black spots on the upper half of the body but usually without spots. The head is olive-green. In preservative a pale greyish brown above, flanks and lower surfaces brilliant silvery or light yellow. Fins greyish to pale olive with lower ones whitish. Iris bright silvery white.

Reaches 60.0 cm (Solijonov, 2007).

Sexual dimorphism

Unknown.

Colour

Usually silvery and occasionally with minute black spots on the upper half of the body. In preservative a pale greyish brown above, flanks and lower surfaces brilliant silvery. Fins greyish to pale olive with lower ones whitish. Iris bright silvery white.

Size

Reaches 50 cm.

Distribution

Found in the basins of the Indus, the Amu Darya and Syr Darya rivers, the Tarim basin and the Helmand (= Hirmand) of Afghanistan and Iran.

Zoogeography

See under genus description.

Habitat

Reported from both lotic and lentic environments but little is known of its environmental requirements.

Age and growth

Life span is at least 8 years. Solijonov (2007), in a study of fishes in the Pamir-Alai Transboundary Conservation Area, found this species as being most active in the evening and so is seldom caught in the daytime when it hides in refuges among rocks. It maintains station in fast water of Pamir-Alai mountain streams behind rocks and in whirlpools. Males mature here at 2-3 years and females at 3-4 years and spawning takes place in mid-May.

Food

Food is small aquatic fauna, vegetation and detritus. Akhrorov and Kondur (1981) found macrophytes, detritus and molluscs to be important foods in a Pamir lake, varying with the year of sampling such that molluscs dominated in one year and macrophtyes in another.

Reproduction

Spawning takes place between May and September, depending on locality, and up to 8678-59,895 eggs are produced in fish 21.5-37.1 cm and 211-913 g (Mitrofanov et al., 1988). Spawning is probably non-annual in some areas (Maksunov, 1971).

Parasites and predators

None reported from Iran.

Economic importance

None.

Conservation

This species is not well-documented in Iran and no assessment of conversation needs can be made. It may be a stray from higher latitudes in Afghanistan.

Further work

Surveys should be done to confirm its presence in Iran.

Sources

Iranian material: None.

Schizothorax labiatus
(McClelland, 1842)

Reported from the Helmand River drainage of Afghanistan; records summarised in Coad (1981d). May be a synonym of Schizothorax intermedius (McClelland, 1842). No Iranian record.

Schizothorax pelzami
Kessler, 1870

Common names

ماهي خواجو (= mahi khvaju or khaju), shir mahi.

[Zakaspiiskaya marinka or Transcaspian marinka, and forel, in Russian].

Systematics

Schizothorax raulinsii Günther, 1889 described from a skin from the "Hari-rud River, near Khusan" and Schizothorax pelzami iranicus Karaman, 1969 are synonyms. Wossughi (1978) considers Schizothorax pelzami iranicus to be only a large specimen of S. p. pelzami and Coad and Keyzer de Ville (2004) concur.

The holotype of Schizothorax Poelzami is in the Zoological Institute, St. Petersburg (ZISP 8036, 265 mm total length) and is from "Fl. Schach-rud. accursus fl. Sefid-rud in Persia. 1889. Univ. Petropol.". The Shah Rud or Shah River is a tributary of the Safid Rud of the Caspian Sea basin but this species does not occur there. Berg (1948-1949) cites A. N. Derzhavin who suggests that this Shah-rud is south of Astrabad (= Gorgan). There is a Shahr Now River in the Tedzhen or Hari Rud basin where this species is found (shahr is the Farsi for city and may have been a general term for a major river of northeastern Iran as it flows through a city). However, the type probably came from the environs of the city of Shahrud (= Emamshahr) in the Damghan basin, a sub-basin of the Kavir basin (see below).

Another specimen listed as a type from the "Schah-Roude. Persia. Pelzame. St. Petersburg University" measuring 78.6 mm standard length is in the Natural History Museum, London (BM(NH) 1897.7.5:24). Kessler (1870) and Eschmeyer (1998) list 4 syntypes so two appear to be lost but Coad and Keyzer de Ville (2004) point out a disparity in size range (120-180 mm for the syntypes according to Kessler (1870)) while the London fish is too small and may not be a type despite its label.

The type of Schizothorax raulinsii from "Bezd. Afghan. Boundary Commission", a skin, is in the Natural History Museum, London although it was not located in a search in 1993 (BM(NH) 1886.9.21:171-172 - the numbering however indicates there were two specimens). Eschmeyer et al. (1996) list a skin and 2 other syntypes in the Natural History Museum, London and 2 syntypes in the Zoological Survey of India, Calcutta (ZSI F11477-78). These 4 additional specimens are presumably the 4 smaller fishes mentioned by Günther (1889) in his original description as being collected at Bezd on the Jam River in Iran.

Schizothorax pelzami iranicus Karaman, 1969 is described from "Teheran in Quelle" (= Tehran in a spring) based on a single specimen. Schizothorax pelzami does not occur in the Namak Lake basin in which Tehran lies and the subspecies may have come from the Damghan part of the Kavir basin. The subspecies differs from the type subspecies by having a weakly ossified spiny ray in the dorsal fin (only the first half with small teeth), smaller eyes, longer snout and an overall brown to blackish-grey body colour with all fins, lips and barbels dark-coloured as opposed to the sharp boundary between the dark brown dorsal side and the light ventral side (Karaman, 1969). The Damghan part of the Kavir basin is the type locality of the species and S. p. iranicus is a synonym (Coad and Keyzer de Ville, 2004).

The holotype of S. p. iranicus is in the Zoologischen Instituts und Zoologischen Museums der Universität Hamburg (ZMH 4116, 327.5 mm standard length).

Starostin (1936) reports a hybrid of this species and Capoeta heratensis (= Capoeta capoeta) from Turkmenistan.

Key characters

This is the only schizothoracine species in northeast Iran and is easily recognised by its high lateral line scale count and the enlarged scales around the anus and anal fin.

Morphology

Dorsal fin branched rays 7-8 after 3-4 unbranched rays, anal fin branched rays 5-6, usually 5, after 3 unbranched rays. Pectoral fin branched rays 16-21, pelvic fin branched rays 7-9. The dorsal fin spine is very strong and thick with well-developed and widely-spaced teeth. Lateral line scales 84-108, lateral series scales 155-170, about 32 between the dorsal fin spine and the lateral line and about 27 between the lateral line and pelvic fin. The belly is scaled up to the isthmus. There is a scaled pelvic axillary process. The anal papilla and anal fin lie in a groove formed by enlarged scales, the groove extending about one third to half way between the anal fin origin and pelvic base. Scales are oval and obliquely inserted into scale pockets on mid-flank, sloping backwards postero-dorsally. The focus is subcentral anterior and radii are present on all fields. Circuli are few in these small scales. Pharyngeal teeth usually 2,3,5-5,3,2. Teeth are rounded with an evident hooked tip and posterior teeth have a short to medium flat grinding surface below the tip. Teeth may also be spatulate or have a spatulate shape with the hollow filled in. Gill rakers 9-15, relatively short and reaching the adjacent raker or slightly beyond when appressed. Occasional rakers are forked. The mouth is inferior. The lower lip is interrupted medially. The lower jaw may have a sharp horny sheath but this is mostly lacking. Mouth shape varies from a u-shape to a sector mouth (a gentle arch), the latter with a horny edge. The anterior barbels extend back to the anterior eye margin or the mid-eye while the posterior barbels extend to the rear eye margin or beyond. Barbel size is variable and not obviously related to size. The gut is very elongate and coiled.

Meristic values for Iranian specimens are:- dorsal fin branched rays 7(11) or 8(22); anal fin branched rays 5(33); pectoral fin branched rays 16(2), 17(4), 18(12), 19(6), 20(8) or 21(1); pelvic fin branched rays 7(2), 8(30) or 9(1); lateral line scales 85(2), 86(2), 88(2), 89(1), 90(2), 91(2), 92(2), 93(2), 95(2), 98(2), 99(7), 100(3), 102(1), 104(1), 105(1) or 108(1); total gill rakers 9(1), 10(5), 11(6), 12(7), 13(8), 14(1), 15(2), 16(1), 17(1) or 18(1); pharyngeal teeth 2,3,5-5,3,2(15), 2,3,4-5,3,2(2), 2,3,5-4,3,2(1), 2,2,5-5,3,2(1), 1,3,5-5,3,2(1); and total vertebrae 43(6), 44(10), 45(1), 46(2), 47(2), or 49(1).

Sexual dimorphism

A male specimen, 123.9 mm standard length, caught on 6 April had small to moderate sized tubercles on the top and sides of the head but these were not fully developed. The largest tubercles are found between the nostrils and the upper lip on the snout. No tubercles were noted on the fins. A fish taken on 5 November also had small but distinctive tubercles.

Colour

The overall coloration is silvery without any pattern but the back and upper flank are blackish to olive or brassy and the belly is whitish in small fish to a strong yellow in large fish. The back may be iridescent blue-green. The lateral line may be lighter than the surrounding flank, appearing as a thin, whitish line. The lips, pectoral, pelvic and anal fins are yellow. Fins bases are bright orange, the gill slit has a bright orange streak and the isthmus is bright orange. All fins may be flushed with red in freshly caught material and the lower flank and belly can have pinkish tinges. The iris is red dorsally. The peritoneum is a dark brown.

Preserved fish have a uniform brown colour with faint to dark speckles arranged irregularly on the flank. There are no obvious patterns on the fins although they are darkened by melanophores on both rays and membranes.

Günther (1889) reports the caudal fin as black, but this is possibly a dried or otherwise abnormal specimen. The colouration of the iranicus nominal subspecies in the original description (cited above) is not borne out by specimens from Damghan, the presumed locality of the type specimen, and again may be an artefact of preservation or simply a variation.

Size

Attains 54 cm (Muhomedieva, 1967) and reputedly 3 kg in qanat specimens (R. J. Behnke, in litt., 1981).

Distribution

Found in the Tedzhen and Murgab rivers of Afghanistan and Turkmenistan including Iranian drainages of the former known as the Hari River in its Iranian reach (Aliev et al., 1988). It is recorded from the Jam River, the Sharak River, the Akhland River near Mashhad, the Kashaf Riverand various smaller water bodies in Khorasan, the upper Kal Shur, Jajarm and Jovein rivers in the Kavir basin, as well as Cheshmeh Ali at Damghan and Cheshmah Badash near Shahrud further west, the westernmost distribution of the schizothoracine fishes (Günther, 1889; Nikol'skii, 1897; 1899; Abdoli, 2000; Coad and Abdoli, 2000b).

Wossughi (1978) records this species from the Hamun-See (= Sistan) but this is an error.

Zoogeography

Saadati (1977) found slight differences between fish from the Kavir basin and from the Hari River basin, in raker counts and caudal peduncle depth. He concludes that isolation in the Kavir basin is relatively recent and migration has occurred westwards in the past 15-25,000 years. The occurrence of this species in the western Kavir basin (the Damghan basin) is the westernmost distribution of the schizothoracine fishes. See also the genus Schizothorax.

Habitat

Found in springs, streams, rivers and qanats, the principal habitats of northeast Iran but environmental requirements are unknown.

Age and growth

Life span exceeds 7 years (Muhomedieva, 1967).

Food

The diet is 93-99% fishes including Cyprinus carpio (Muhomedieva, 1967). Other foods include small Capoeta capoeta, Cyprinus carpio, chironomids, caddis flies, dragonflies, other aquatic insects, and plant material (Aliev et al., 1988). Crustaceans, plant fragments and filamentous algae, and possibly fish eggs, may also be found in gut contents. Abdoli (2000) lists Plecoptera, Ceratopogonidae, Trichoptera, Ephemeroptera, Chironomidae and Simuliidae.

Reproduction

Egg diameter reaches 2.0 mm and numbers reach 36,300 eggs (Aliev et al., 1988). Iranian fish caught on 6 April had developing eggs suggesting a spring or early summer spawning period.

Parasites and predators

None reported from Iran.

Economic importance

None.

Conservation

The numbers and details of distribution need to be examined before an assessment can be made.

Further work

The biology of this species in Iran is unknown in detail.

Sources

Type material: See above, S. pelzami (ZISP 8036) (and possibly (BM(NH) 1897.7.5:24)) and S. p. iranicus (ZMH 4116).

Iranian material: CMNFI 1993-0124A, 1, 118.7 mm standard length, Semnan, Cheshmeh Ali-Damghan (36º17'N, 54º05'E); CMNFI 2007-0003, 8, 94.3-188.1 mm standard length, Semnan, Cheshmeh Ali (ca. 36º17'N, ca. 54º46'E); CMNFI 2007-0004, 6, 75.6-109.5 mm standard length, Semnan, Cheshmeh Bedasht (ca. 36º35'N, ca. 55º03'E); CMNFI 2007-0012, 2, 77.8-127.6 mm standard length, Khorasan, qanat at Bagh-e Jan (ca. 36º00'N, 58º38'E); CMNFI 2007-0013, 2, 55.9-80.4 mm standard length, Khorasan, qanat 5 km north of Boghai (ca. 36º02'N, ca. 59º31'E); CMNFI 2007-0014, 3, 88.7-98.1 mm standard length, Khorasan, Kuh-e Sang Park, Mashhad  (ca. 36º18'N, ca. 59º36'E); BM(NH) 1914.1.1:16-17, 2, 98.0-163.9 mm standard length, Khorasan, Kashaf River, Mashhad (no other locality data); BM(NH) 1914.1.1:18-20, 3, 138.5-242.0 mm standard length, Khorasan, small stream near Mashhad (no other locality data); BM(NH) 1914.1.1:21-23, 2, 151.2-165.7 mm standard length, Khorasan, Cheshmeh-e Saby (no other locality data); BM(NH) 1914.1.1:24-29, 5, 147.6-188.8 mm standard length, Khorasan, Langar, Jam River (35º23'N. ca. 60º25'E).

Schizothorax plagiostomus
Heckel, 1838

Described from Kashmir; records summarised in Coad (1981d) for the Helmand River basin in Afghanistan but these may refer to Oreinus plagiostomus, a probable synonym of Schizothorax intermedius (q.v.). No Iranian record.

Schizothorax zarudnyi
(Nikol'skii, 1897

Common names

hamun mahi (= hamun or lake fish), mahi khvaju (after the historic island in Lake Hamun), sefidak or vatani (A. A. Pasand, pers. comm., 5 November 2000), shir mahi (= milk fish), anjak (Fowler and Steinitz (1956) report three kinds of fish being caught by fishermen in Sistan named anjaq (hence Oreinus anjac, see below), mawda (? unknown) and mahrmahé (= mar mahi, snake fish, probably a Nemacheilus)).

Systematics

The holotype of Aspiostoma zarudnyi is in poor condition with the tail detached and the body impaled on a wooden spike when examined by me. Nikol'skii (1897) in his original description states in Latin "Specimen valde destructum". It is in the Zoological Institute, St. Petersburg (ZISP 11195a) and measures about 265 mm standard length. Nikol'skii (1897) gives the catalogue number as 11115 (sic, incorrectly according to Berg (1949)) and the type locality as "Palus Neizar in Seistan. 3.VI.96.". Berg (1949) gives the collection locality as "Neizar near the southern tip of Lake Hamun-i-Farah, western edge of the Helmand delta in northwestern Seistan" based on Zarudnyi (1901).

This species was originally described in the genus Aspiostoma Nikol'skii, 1897, a synonym of Schizothorax Heckel, 1838 (Eschmeyer, 1990). Bianco and Banarescu (1982) place this species as Schizopyge zarudny, the species name being a mis-spelling. Schizopyge Heckel, 1847 is regarded by these authors as the correct name for snow trouts without a suctorial disc on the chin (synonym Schizothoraichthys Misra, 1962 (see discussion above under the genus Schizothorax).

Barbus microlepis Keyserling, 1861 described from "Flüsschen bei Anardareh, zwischen Herat und Lasch" is a synonym and is pre-occupied by Barbus microlepis Bleeker, 1851. Oreinus anjac Fowler and Steinitz, 1956 from "Zabol, Eastern Iran" is also a synonym as suggested by Saadati (1977) although it may be a hybrid.

The holotype of Oreinus anjac (ANSP 71949) at 281 mm total length is stored in the Academy of Natural Sciences of Philadelphia (Böhlke, 1984).

This species is closely related to Schizothorax intermedius but is distinguished by much smaller paired fins, longer and narrower branchial isthmus, and the scales slightly enlarged at the base of all fins, especially the dorsal and anal (Annandale and Hora, 1920).

Key characters

The only common Schizothorax species in Sistan, is is recognised by the large barbels and enlarged scales around the anal fin.

Morphology

Dorsal fin with 4 unbranched and 7-8 branched rays, anal fin with 3 unbranched and 5 branched rays. The last unbranched dorsal fin ray is moderately strong and serrated, the serrations being proportionately longer and spinier in young. Pectoral fin branched rays 18 and pelvic fin branched rays 9. Lateral line scales 97-114, at least 190 in the scale series immediately above the lateral line. The breast is naked or sparsely scaled. There is a pelvic axillary process. The scale sheath around the anal papilla and anal fin extends about one third to half way between the anal fin origin and the pelvic fin base. Scales are very small, horizontally ovoid and have an almost central focus. Scales are obliquely inserted in the scale pockets on the mid-flank above the lateral line and below the dorsal fin. Scales on the nape are none to minimally imnbricate. Radii are found on all fields and are numerous. Gill rakers on the lower arm 30-39 (Nikol'skii's (1897) count of 25 is incorrect (Berg, 1949); but see below for wider variation). Gill rakers are long, reaching the third to the sixth adjacent raker when appressed. The interior margin of each raker is serrated. Pharyngeal teeth usually 2,3,5-5,3,2, spoon-shaped with a slightly hooked tip. Anterior teeth are more rounded and thicker. There are 2 pairs of barbels, the anterior ones long to rudimentary in literature sources. The barbels are subequal in length, the anterior ones not reaching the eye and the poterior ones not reaching beyond the eye. The mouth is usually slightly subterminal but can be terminal or have the lower jaw projecting slightly. The gut is elongate and coiled. The chromosome number is 2n=96, NF=142, comprising 9 pairs of metacentric, 14 pairs of submetacentric and 25 pairs of acrotelocentric chromosomes, and the fish is a tetraploid (Hosseini and Kalbasi, 2003; Kalbassi et al., 2008).

Meristics for Iranian specimens: dorsal fin branched rays 7(2) or 8(34); anal fin branched rays 5(35); pectoral fin branched rays 16(1), 17(7), 18(10) or 19(16); pelvic fin branched rays 9(30) or 10(5); lateral line scales 93(1), 97(1), 98(2), 99(3), 100(4), 101(5), 103(4), 105(2), 106(5), 107(2), 108(1), 109(2), 113(1) or 114(1); total gill rakers 24(1), 25(1), 26(1), 27(1), 28(1), 29(1), 31(5), 34(6), 35(2), 36(8), 37(1), 38(2), 40(1) or 41(1); pharyngeal teeth 2,3,5-5,3,2(14), 2,3,5-5,3,3 (1), 2,3,5-5,2,1(1), 2,3,5-5,3,1(1), 2,2,5-5,3,2 (1), 2,2,5-4,2,2(1), 2,3,4-5,3,2(2), 2,3,4-4,3,2(1) or 1,2,5-5,3,2(1); and total vertebrae 47(11), 48(11) or 49(4).

Sexual dimorphism

Males develop prominent nuptial tubercles on the snout and on the scales. Females have a soft and distended belly during the breeding season (CIRSPE, 2006b).

Colour

Overall colour is silvery, the back and head darker with indistinct fine dots. The flanks may be spotted with black and some small areas may be more lightly pigmented and appear as indistinct spots or blotches. There are melanophores on the fin rays and membranes. Adult males may have reddish fins and dull red specks on the dorsal surface. Young are more silvery than adults. Generally there is no distinctive pattern on the body and fins.

Colour varies with the environment. In muddy water, the back and fins are pale olive-green, the flanks tinged with green and the belly pure white while in the yellow water of the reed beds the back and flanks are much darker, almost black, and even the belly is darkish. The peritoneum is brown to black.

Size

Reaches 62.1 cm total length and and over 2.2 kg. Ahmadi and Wossughi (1988) give average weights of 300 to 2000 g in commercial catches while fish more than 12 kg are reported recently (Iranian Fisheries Research Organization Newsletter, 30-31:5, 2002).

Distribution

This species is restricted to the Sistan basin including the Chahnimeh (Nikol'skii, 1897; Bianco and Banarescu, 1982; J. Holčík, in litt., 1996.

Zoogeography

See under the genus description.

Habitat

Found in the open lake, in reed beds and in pools in Sistan (Annandale, 1921). It is the only species in Sistan common in the open lake in winter. Young probably make their way up upstream in the flood season as only adults are found in the lake in winter. The species is extremely abundant in pools left in stream beds when the floods recede. Spawning may occur in rivers as fry have not been found in the lakes (Iranian Fisheries Research Organization Newsletter, 30-31:5, 2002). Zabihi (2006) characterises it as a potamodromous species and notes that in March and April, if there is no flow in the rivers and thus no migration from the lake is possible, female gonads are reabsorbed.

Age and growth

Sexual maturity may only be attained after 4 years. Zabihi (2006) examined 697 specimens with a length and weight range of 24.5-62.1 cm and 137-2204 g. Half the male fishes were mature at 29-31 cm and for females at 38-40 cm.

Food

The diet comprises almost exclusively small fishes.

Reproduction

Eggs in fish caught in spring by me were developing but very small. Specimens with mature, yellow eggs have been caught in December. However this species is mature in Esfand (20 February-20 March), incubation is 6-7 days at 16.20-17.75ºC, maximum egg diameter is 3.8 mm when washed and the yolk sac is absorbed at 6-7 days (M. Abedi, Islamic Azad University of Savad Kooh, abstract). Zabihy et al. (2004) and Zabihi (2006) found maximum oocyte size in March and April at 14-18ºC when the gonadosomatic index was highest at 7.9-9.6. The mean absolute and relative fecundities for fish 460-1380 g was 26,256 and 34,418 eggs respectively. The species was a total spawner showing a synchronous ovary. Eggs are adhesive to prevent them being washed away by strong currents (CIRSPE, 2006b).

Parasites and predators

Datta (1937) describes the male of the acanthocephalan Eosentis rigidus from the intestine of this species.

Economic importance

Annandale in Annandale and Hora (1920) described the fishery for this species in the early years of the 20th century. Annandale commented that the flesh tasted like trout but was bony. The bones can be softened by cooking in vinegar. This fish is still caught and eaten and appears in local markets. Ahmadi and Wossughi (1988) cite an annual catch of 300-500 t while Iran Daily (24 August 2006) gives 700-1000 t before the drought.

Annandale and his assistants became sick from eating the eggs of this species but he maintained that the local fishermen ate it without any deleterious effects. Fish were caught in a net about 4 feet (1.22 m) deep and 100 feet (30.5 m) or more long anchored at each end by a tamarisk stick stuck into the lake bottom and with the bottom of the net on the lake bed and the top of the net slightly above the surface. The net was positioned in relation to the wind, and therefore the prevailing currents, so it formed a semi-circle. The net was arranged in a gap in the reed beds or just outside the reeds in the open lake if the weather was exceptionally calm. Pools in the reeds were kept open to facilitate the fishing. The fishermen riding their tutins (reed boats) would drive the fish into the net by beating the water with poles and ululating. The two ends of the net were then lifted out of the water by the men in the two end boats such that the net formed a bag. The net was drawn into the two boats as rapidly as possible. A similar but shorter net was used to drag small channels while the men using it waded. A small-meshed bag net attached to one horizontal and two upright poles was also used in pools of dry stream-beds. The net was dragged by ropes, the men wading through the water. Some large fish were killed in the flooded swamps by striking at them with swords. Another net consisted of a bag about 7 feet (2.14 m) long and 6 feet (1.83 m) by 2 feet (0.61 m) at the mouth. The mouth was held open by poles tied together at one end to make a fork. The fork pivoted on a post on the bank. The mouth of the net had fine lines across it, the lead string of which was held by the fishermen to warn him that a fish had entered the net so he could pull the net out of the water to retrieve the fish. The net was placed along a bank where the current swirled forming a backwater, at the mouth of a small canal, or as the focus of a line of stakes blocking a channel. The season for this type of net began as early as August or not until October. It lasted several weeks. March and April could also be a favourable time if the river was not very full but the fish did not move as actively. The large fish caught were attracted to feed on the numerous small fish which migrated up river along the shore and were checked where backwaters met the main flow.

A more recent description of fishing in Sistan is found in Fowler and Steinitz (1956). Fishing takes place in fall on rivers and in the lake, preferably the early evening or morning when it is cool. River fishing is preferred to lake fishing and some fishermen never go out onto the lake. Lake fishing using boats may last up to 3-5 days at a time. River fishing is carried out with a cotton-thread seine weighted by stones at the bottom and with gourds as floats. The seine is tied to sticks at each end and the sticks to ropes leading to shore. Four to ten men can own a seine and the catch is divided among those fishing that day. Fishing is done in teams of 4-7 men or often in two teams with two nets. Half the men are on one side of the river and half on the other, pulling each other's nets in and out of the water. Only large, fat fish are kept, the others being thrown back. One net catches 30-40 fish in a day which are then sold in Zabol. Women never fish nor are present during fishing as they bring bad luck. Fish are always cooked before eating as eating raw fish is reputedly fatal.

Conservation

Ahmadi and Wossughi (1988) state that introductions of various fishes such as Cyprinus carpio, Carassius auratus, Ctenopharyngodon idella and Hypophthalmichtys molitrix are a possible source of competition for native species such as this schizothoracine since they are voracious, take spawning sites and carry diseases and parasites. Native catches have decreased in favour of introduced species. M. Abedi, Islamic Azad University of Savad Kooh, has studied artificial reproduction in this species including larval development. CIRSPE (2006b) and Iran Daily (24 August 2006) give details on artificial reproduction of this species. Males over 600 g and females over 900 g were found to be suitable for breeding, ideal water temperature range was 18-22ºC, fecundity range was 24,300-37,640 eggs for fish 0.8-1.1 kg, egg size was 1.54 mm (presumably not water hardened; see above), and survival from egg to 11 mm fingerling was about 10%.

Further work

The molecular relationships of this species to other Schizothorax species and related genera could be revealing.

Sources

Type material: See above, Aspiostoma zarudnyi (ZISP 11195a).

Iranian material:- CMNFI 1979-0072, 1, 199.1 mm standard length, Sistan, Hirmand River near Zabol (30º58'N, 61º28'E); CMNFI 1979-0223, 1, 34.4 mm standard length, Sistan, irrigation jube 1 km south of Lutak (30º45'N, 61º24'E); CMNFI 1979-0225, 11, 182.2-225.3 mm standard length, Sistan, effluent of Hirmand River (30º58'N, 61º28'E); CMNFI 1979-0226, 2, 146.8-167.2 mm standard length, Sistan, pool near Kuh-e Khajeh (30º57'N, 61º17'E); CMNFI 1979-0231, 2, 23.1-25.8 mm standard length, Sistan, irrigation jube 3 km from Zabol (31º01'N, 61º32'E); CMNFI 1979-0232, 2, 26.3-26.5 mm standard length, Sistan, irrigation jube 11 km from Zabol (ca. 30º58'30"N, ca. 61º36'E); CMNFI 1979-0235, 13, 148.4-193.7 mm standard length, Sistan, effluent of Hirmand (30º54'30"N, 61º41'E); CMNFI 1979-0237, 8, 24.4-45.3 mm standard length, Sistan, irrigation jube 18 km south of Zabol (30º53'N, 61º27'30"E); BM(NH) 1920.1.20:35, 1, 232.5 mm standard length, Sistan, near Lab-e Baring (ca. 31º07'N, ca. 61º12'E); ZMH 5902, 2, 372.3-369.7 mm standard length, Sistan, Hamun See (no other locality data); ZMH 5903, 3, 274.2-298.7 mm standard length, Sistan, Hamun See (no other locality data); ZMH 6088, 2, 48.3-136.1 mm standard length, Sistan, Rud Sistan (no other locality data).

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