Genus Hemiculter
Bleeker, 1859

This genus contains several species with a native distribution in the Amur River basin of the Russian Far East and in China, Taiwan and Viet Nam. A single species has been accidentally introduced to Iran.

The sawbellies are characterised by an elongate body; moderate-sized scales with a deeply-decurved lateral line only 1-3 scales above the mid-ventral line; a scaleless keel from the pectoral fins to the vent; a short dorsal fin with a spine and an elongate anal fin; pharyngeal teeth in 3 rows; gill rakers short and numerous; and pelagic eggs.

Hemiculter leucisculus
(Basilewsky, 1855)

Common names

tizeh kuli or teez-e-kooli (= sharp or spiny fish, kuli being any small fish), shakam tiz (= ?sharp belly), kuli-e mordab (= lagoon fish).

[vostrobryushka or sharpbelly in Russian; common sawbelly, knifefish].

Systematics

Culter leucisculus was originally described from Peking, China. Hemiculter eigenmanni (Jordan and Metz, 1913) is a synonym.

Key characters

The sharp keel, lacking scales, extending from the vent or anus to the throat below the pectoral fin on the mid-ventral surface is distinctive, especially when combined with the dorsal fin spine and the three rows of pharyngeal teeth.

Morphology

The last dorsal fin unbranched ray is a sharp spine with a flexible tip. The lateral line curves downward from its origin on the head to the level of the end of the pectoral fin and then parallels the lower body margin eventually to curve upward (sometimes sharply) at the end of the anal fin level and run along the middle part of the caudal peduncle. There is a tubercle on the lower jaw which fits into a notch on the upper jaw. Dorsal fin branched rays 6-8, usually 7, after 2-3 unbranched rays and anal fin branched rays 10-18, mostly 13-14 (but see below), after 3 unbranched rays. Lateral line scales 43-55, scales above the lateral line 8-11, and scales below the lateral line to the pelvic fin origin 1-3. Scales bear numerous fine circuli and a few posterior radii. Total gill rakers 17-29, reaching the second raker below when appressed. Pharyngeal teeth, 2,4,5-5,4,2, 2,4,5-4,4,2, 2,4,4-5,4,2, 2,4,4-4,3,2, 3,4,5-4,3,2 or 2,3,5-4,3,2. Teeth are hooked at the tip with an elongate and narrow grinding surface. Total vertebrae 42. The gut is an elongate s-shape. The chromosome number is 2n=48.

Meristic values for Iranian specimens are:- dorsal fin branched rays 6(1) or 7(6), anal fin branched rays 11(1), 12(5) or 13(1), lateral line scales 47(1), 48(1), 50(1), 52(1), 53(1) or 54(2), total gill rakers 17(1), 18(4) or 19(2), and pharyngeal teeth 2,4,5-5,4,2(2), 2,4,4-5,4,2(2), 2,4,5-4,4,2(2) or 2,4,4-4,3,2(1).

Sexual dimorphism

Unknown.

Colour

Overall colour dark above, silvery on the flanks and whitish on the belly. There is a dark stripe along the upper flank. The lips are dark. The dorsal, caudal and anterior pectoral and anal fin ray edges and their fin membranes are lightly pigmented with melanophores. The peritoneum is silvery with some melanophores giving it a brownish pigmentation in preserved fish.

Size

Reaches 25 cm.

Distribution

The native range of this species is from Maritime Russia south through China to Korea and Viet Nam. First reported from the Anzali Mordab by Holčík and Razavi (1992) and apparently not uncommon there. Abbasi et al., (1999), Kiabi et al. (1999), Abdoli (2000) and Gasmi and Mirzaei (2004) record this species from the lower Safid River and the Anzali Talab, and in the middle Aras River. Patimar et al. (2002a; 2002b) report it from the International Wetlands of Alma-Gol, Adji-Gol and Ala-Gol. Found in ab-bandans along the Caspian shore of Iran (Jolodar and Abdoli, 2004). Also reported in the Tedzhen River, Karakum Canal and Kopetdag Reservoir of Turkmenistan (as H. eigenmanni)(Aliev et al., 1988; Shakirova and Sukhanova, 1994; Sal'nikov, 1995) and so may eventually be found in the Tedzhen (= Hari) River basin of Iran. Now recorded from the Hawizah Marsh in southern Iraq (Coad and Hussain, 2007).

Zoogeography

This species is introduced to Iran, probably by accident along with commercial shipments of Chinese major carps from Central Asia in the former U.S.S.R. and/or Rumania in 1967. The Chinese major carps in Central Asia came from the Amur River basin in the Far East and sawbellies were accidentally transferred with them in the 1950s-1960s (Holčík and Razavi, 1992).

Habitat

Found in rivers, lakes, small ponds and swamps but little appears to be known about its habitat requirements.

Age and growth

Patimar et al. (2002a; 2002b) report six age groups in the International Wetlands of Alma-Gol, Adji-Gol and Ala-Gol. The smallest mature specimens there were 2 years old. It is an 'r' strategist, forming dense stunted populations in any new environment.

Food

Macrophytes, fish, crustaceans and insects are eaten by this species and young fish feed on zooplankton. Iranian fish contain large plant fragments and filamentous algae.

Reproduction

Up to 1,180 eggs are produced. Fish from a swamp near Hendeh Khaleh in Gilan taken on 9 August contained well-developed eggs but Patimar et al. (2002a; 2002b) report a peak spawning in March in the International Wetlands of Alma-Gol, Adji-Gol and Ala-Gol.

Parasites and predators

Sattari et al. (2007) record the digenean Diplostomum spathaceum and the monogenean Diplozoon sp. in this species in the Anzali wetland of the Caspian shore. It is food for Sander lucioperca, Silurus glanis and Aspius aspius in Turkmenistan (Aliev et al., 1988).

Economic importance

This species has potential as a food fish and is canned in China but this is probably outweighed by its competition with native species for food and the possibility of predation on fish eggs and young. The sawbelly is easily able to switch from one food to another as conditions warrant (Holčík and Razavi, 1992) and is known to show more rapid growth and higher fecundity than under native conditions. Welcomme in Courtenay and Stauffer (1984) regards this species as a pest when introduced.

It is found on the fish market at Bandar Anzali and a catch of 41 kg is reported from the Anzali Mordab in 1990 (Holčík and Oláh, 1992).

Conservation

None required for an introduced species.

Further work

The spread of this species and its effects on native species and habitats should be monitored.

Sources

Based on data in Holčík and Razavi (1992) for 5 Iranian specimens from the Anzali Mordab (134.5-143.4 mm standard length).

Iranian material: Uncatalogued material, 2, 99.6-113.1 mm standard length, Gilan, swamp near Hendeh Khaleh (37°23'N, 49°28'E).

Comparative material: CMNFI 2006-0028, 2, 112.5-123.6 mm standard length, Iraq, Hawizah Marsh (31º38'30"N, 47º35'21"E and 31º36'02"N, 47º33'09"E).

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