Blicca bjoerkna (Linnaeus, 1758)
White bream
Blicca bjoerkna
photo by Hartl, A.

Family:  Leuciscidae (Minnows), subfamily: Leuciscinae
Max. size:  45.5 cm TL (male/unsexed); max.weight: 1,000.0 g
Environment:  demersal; freshwater; brackish; depth range - 0 m, potamodromous
Distribution:  Europe and Asia: North, Baltic, White, Black (south to Rioni drainage) and Caspian Sea basins, Atlantic basin southward to Adour drainage (France; possibly introduced southward of Loire) and Mediterranean basin in France (Hérault and Rhône drainages). In Aral, Marmara and Anatolian Black Sea basins west of Ankara. Naturally absent from Iberian Peninsula, Italy, Adriatic basin, Crimea, Great Britain (except southeast), Scandinavia north of Sundsvall (Sweden) and 65° N (Finland). Locally introduced in Spain and northeastern Italy; in France, apparently introduced in smal coastal drainages of Var.
Diagnosis:  Dorsal spines (total): 3-3; Dorsal soft rays (total): 8-8; Anal spines: 3-3; Anal soft rays: 19-22; Vertebrae: 39-40. The only species of the genus which can be diagnosed from similar species of genera Ballerus, Blicca and Vimba by having the following characters: mouth sub-inferior, which can not be extended as a tube; scales on lateral line 43-46 + 2-3 ; anal fin with 19-23½ branched rays; eye diameter about equal to snout length in individuals larger than 10 cm SL; pharyngeal teeth 2,5-2,5; and orange or reddish base of paired fins (Ref. 59043). Caudal fin with 17-19 rays (Ref. 2196).
Biology:  Gregarious and frequents stagnant waters of lakes and reservoirs, rivers and canals with calm waters. Occurs in a wide variety of shallow, warm lowland lakes and slow-flowing lower reaches of large rivers and canals. Frequently very abundant on bottom of large sandy rivers. Larvae live in still water bodies. Mainly nocturnal. Feeds on benthic invertebrates. Spawns along shores on submerged vegetations, roots or even on shallow gravel bottom (Ref. 59043). Reproduction takes place in May to July. Exhibits polyandry (Ref. 6114). Regularly hybridizes with Vimba vimba (Ref. 59043). Of little interest to game fishers and consumers (Ref. 30578). Unpopular with commercial fishers due to its small size and competition with more desired species.
IUCN Red List Status: Least Concern (LC); Date assessed: 01 January 2008 Ref. (130435)
Threat to humans:  harmless


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