Genus Blicca
Heckel, 1843

Shutov (1969) places this genus and species in the genus Abramis Cuvier, 1817 on the basis of literature data as does analyses by Shcherbukha (1973) and Howes (1981). Hensel (1978) and Tadajewska (1998) also place this genus in Abramis on the basis of the lateral line system structure, pharyngeal teeth, scale and dermal bone morphology along with data on ecology, behaviour, ontogenesis, osteology and parasitofauna. Hänfling and Brandl (2000) consider Blicca a junior synonym to Abramis based on allozyme data. In contrast, Bogutskaya (1986) using skull morphology reaffirms its generic status.

The white bream genus contains a single species found from Europe to the Caspian Sea basin including Iran.

The genus is characterised by a deep and strongly compressed body; scales absent on the back behind the dorsal fin thus forming a narrow groove; a scaleless keel between the vent and the pelvic fins; pharyngeal teeth in 2 rows; a small, oblique and subterminal mouth; moderate number of gill rakers; scales of moderate size; a short and spineless dorsal fin and a long anal fin; and a light peritoneum.

Blicca bjoerkna
(Linnaeus, 1758)

Common names

simparak or seamparak (= silver scales, possible meaning since parak is a small feather), سيم نما (sim nama or mahi sim nama, meaning silvery-like fish or sim-like fish in reference to Abramis brama).

[yastigarin in Azerbaijan; Zakavkazskaya gustera or Transcaucasian white bream, Armyanskaya gustera for A. b. derjavini, all in Russian; silver bream, white bream, flat bream].

Systematics

Cyprinus Björkna was originally described from Lake Mälar, Sweden.

Cyprinus Blicca Bloch, 1782 described from lakes in Germany, Cyprinus gibbosus Pallas, 1814 described from the Sura and Volga rivers and Blicca argyroleuca Heckel, 1843 are synonyms. It appears that the latter taxon is first described in Heckel's work on fishes of Syria, but in the section devoted to classification based on the pharyngeal teeth of cyprinids; the taxon is later described from Europe in Heckel and Kner (1858) and is not a Southwest Asian species. Syntypes of Blicca argyroleuca are in the Naturhistorisches Museum Wien under NMW 16901 (2 fish), NMW 54918 (6), NMW 54919 (4) and NMW 54920 (1) (Eschmeyer et al., 1996). The spelling bjorkna is incorrect (Eschmeyer et al., 1996).

The Caspian Sea basin subspecies is Blicca bjoerkna transcaucasica Berg, 1916, described from the lower reaches of the Kura River, Araks, Lenkoran District, Transcaucasia. It is distinguished by "somewhat" fewer rays in the anal fin (17-21) and "a tendency to have" fewer lateral line scales (40-45) than in the type form which mostly has 21-22 anal fin rays and 45-48 lateral line scales (Berg, 1948-1949). Abdurakhmanov (1962) expands these ranges to 17-22 and 40-48 respectively but gives low means (± standard error) for 100 fish from Azerbaijan of 19.88±0.13 and 43.56±0.05 respectively. This may be a valid subspecies but the possibility of clinal variation has not been examined.

Blicca bjoerkna derjavini Dadikyan, 1970 is described from the "Sevdzhur River, (tributary of Araks River, in Armenian SSR) and the canal and lake system connected with it". It is distinguished from transcaucasica by lower mean number of branched dorsal fin rays and branched anal rays, a higher mean lateral line scale count, and various morphometric characters.

Key characters

The scaleless ventral keel, postdorsal groove, long anal fin, lateral line scale count and small and oblique mouth are characteristic.

Morphology

Dorsal fin with 3 unbranched and 7-10 branched rays, usually 8, anal fin with 3 unbranched and 16-24 branched rays. Pectoral fin branched rays 14-16, pelvic fin branched rays 7-9. Lateral line scales 40-55. Scales have numerous fine circuli, an almost central focus, a wavy anterior margin and a crenulate posterior margin, and few primary anterior and posterior radii, as few as 2 in each field (there may be numerous secondary radii which do not reach the focus). There is a pelvic axillary scale. Gill rakers 12-21, touching the adjacent raker when appressed. Vertebrae 37-43. Pharyngeal teeth 2,5-5,2 with variants 2,5-5,1, 1,5-5,2, 1,5-5,1, 2,5-4,2, 2,5-4,1, 1,5-4,1, 3,5-5,2, and 3,5-5,3 (among others, see below and Tadajewska (1998)), weakly hooked (strongly hooked in young), compressed, concave below the tip and smooth (anterior tooth margin serrated in young). In young fish, the first major row tooth may be medial to the second tooth rather than in line. Tadajewska (1998) gives details of tooth development. The intestine is s-shaped with a small anterior loop. The chromosome number is 2n=50 (Klinkhardt et al., 1995).

Meristic values for Iranian specimens are:- dorsal fin branched rays 8(49) or 9(1); anal fin branched rays 17(3), 18(15), 19(21), 20(9) or 21(2); pectoral fin branched rays 14(15), 15(24) or 16(7); pelvic fin branched rays 7(1), 8(47) or 9(2); lateral line scales 41(2), 42(10), 43(9), 44(13), 45(10), 46(5) or 47(1); total gill rakers 13(2), 14(25), 15(18), 16(4) or 18(1); pharyngeal teeth 2,5-5,2(3), 2,5-5,1(4), 1,5-5,2(4), 2,5-4,1(1), 2,5-5,0(1), 0,5-5,2(1), 1,5-5,1(1), 1,5-5,0(2), 1,5-4,1(2) or 2,4-4,1(1); and total vertebrae 38(8), 39(33) or 40(12).

Sexual dimorphism

Breeding males have fine tubercles on the top of the head, operculum and lining the exposed scale margins on the flank. There are occasionally tubercles in mid-scale. Small tubercles are found on the pectoral fin rays, 1-3 rows on the unbranched ray, 1-2 on the first branched ray and usually 1 on the other rays, branching to follow the branching rays. Other fins bear fine tubercles following the fin rays. Larger tubercles are found in clumps on the scales overlapping the anal fin base. Tubercles are absent from the belly. Fine unculi are present on the snout, under the eye and between the tubercles on the head generally as well as on the underside of the pectoral fin.

Colour

The back is a bluish-green and the rest of the body silvery. The pectoral and pelvic fins are orange-red with grey tips. The peritoneum is silvery with scattered melanophores.

Size

Reaches 54.5 cm and 1.8 kg.

Distribution

Found from England through Europe north of the Alps and Pyrenees to the Caspian Sea basin. Apparently it does not penetrate to the higher reaches of even major rivers like the Kura and Aras. In Iran it is found from the Aras River (including its middle reaches in Iran) to the Atrak River in the Caspian Sea basin including the Anzali Talab (Derzhavin, 1934; Holčík and Oláh, 1992; Nejatsanatee, 1994; Abbasi et al., 1999; Kiabi et al., 1999; Abdoli, 2000).

Zoogeography

This species is part of a northern European and northern Southwest Asian fauna whose zoogeographical history has not been thoroughly researched. The relationships with similar genera are reviewed under the genus.

Habitat

This species is found in the shallows of warm lakes with heavy vegetation and in the slower reaches of rivers including river estuaries in Iran (Jolodar and Abdoli, 2004). It overwinters in deeper water. There was a mass mortality of this species on the Babol Sar beach on 24 June 1963 (USNM 271217).

Age and growth

Growth is slow with maturity attained at 3-5 years and 10-12 cm. Some males may mature at 2 years. Females are much larger than males of the same age. Life span is up to 16 years. Stunted populations comprising large numbers of individuals develop where predators are absent.

Food

Food items include insect larvae such as chironomids, worms and molluscs, and some vegetation. This is a euryphagous species. Young fish feed principally on copepods and cladocerans. Even adults will feed on plankton and it is less of a bottom feeder than Abramis brama.

Reproduction

Spawning in the Volga delta takes place about the beginning of May at around 11°C water temperature but may run from the end of April to the middle of July in the Volga generally. Spawning in the Aras flood plain occurs in the middle of April. Generally spawning occurs later than in Abramis brama and Rutilus rutilus but may overlap and infertile hybrids result. Shallow weedy areas are preferred. Each female is pursued by several males. Fecundity reaches 109,000 eggs and egg diameter 1.44 mm. Eggs adhere to plants or stones on the bottom. There can be 3 spawnings at intervals of 10-11 days when water temperatures are at least 16-17°C. Batch spawning shows much individual variation as well as varying between localities and by year at the same locality.

Parasites and predators

Khara et al. (2006a) record the eye fluke Diplostomum spathaceum for this fish in the Amirkalayeh Wetland in Gilan. The Caspian seal, Pusa caspica, is a predator on this species (Krylov, 1984) as are a variety of other fishes such as perch (Perca fluviatilis) and pike-perch (Sander sp.).

Economic importance

Holčík and Oláh (1992) report a catch of 144 kg in the Anzali Mordab in 1990.

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

Conservation

Lelek (1987) classifies this species as intermediate in Europe (liable to be transferred to vulnerable or rare categories if their habitat deteriorates further). Kiabi et al. (1999) consider this species to be of least concern in the south Caspian Sea basin according to IUCN criteria. Criteria include sport fishing, abundant in numbers, habitat destruction, 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 needs study in Iran.

Sources

CMNFI 1970-0510, 1, 56.0 mm standard length, Gilan, Golshan River (37º26'N, 49º40'E); CMNFI 1970-0522, 4, 40.0-62.6 mm standard length, Gilan, Safid River at Astaneh Bridge (36º16'30"N, 49º56'E); CMNFI 1970-0532, 6, 30.0-63.2 mm standard length, Gilan, Caspian Sea near Bandar-e Anzali (37º28'N, 49º27'E); CMNFI 1970-0553, 4, 62.1-80.1 mm standard length, Gilan, Sowsar Roga River (37º27'N, 49º30'E); CMNFI 1970-0579, 2, 52.6-56.9 mm standard length, Gilan, Old Safid River estuary (37º23'N, 50º11'E); CMNFI 1970-0580, 31, 31.8-86.3 mm standard length, Mazandaran, river near Iz Deh (36º36'N, 52º07'E); CMNFI 1970-0582, 1, 70.9 mm standard length, Mazandaran, Aliabad Reservoir (36º56'N, 54º50'E); CMNFI 1970-0585, 39, 32.4-52.5 mm standard length, Gilan, Nahang Roga River (37º28'N, 49º28'E); CMNFI 1970-0587, 36, 34.6-55.4 mm standard length, Mazandaran, Babol Sar (36º43'N, 52º39'E); CMNFI 1979-0470, 2, 44.5-51.2 mm standard length, Mazandaran, stream west of Alamdeh (36º35'N, 51º43'E); CMNFI 1979-0472, 30, 38.7-69.6 mm standard length, Mazandaran, stream west of Mahmudabad (36º37'N, 52º12'E); CMNFI 1979-0685, 3, 63.1-67.1 mm standard length, Gilan, Safid River (37º24'N, 49º58'E): CMNFI 1980-0117, 1, 80.0 mm standard length, Gilan, Golshan River (37º26'N, 49º40'E); CMNFI 1980-0122, 15, 38.7-45.3 mm standard length, Mazandaran, Nerissi River (36º38'N, 52º16'E); CMNFI 1980-0149, 6, 60.1-63.7 mm standard length, Gilan, Chabak River (37º21'N, 49º50'E).

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