Ballerus sapa (Pallas, 1814)
White-eye bream
Ballerus sapa
photo by Otel, V.

Family:  Leuciscidae (Minnows), subfamily: Leuciscinae
Max. size:  35 cm TL (male/unsexed)
Environment:  benthopelagic; freshwater; brackish
Distribution:  Europe and Asia: large rivers draining to Black, Azov, Caspian and Aral Seas. Introduced or native to Northern Dvina drainage (White Sea basin) where it is presently spreading from warmer upper reaches (Vychegda system) northward. Introduced in River Volkhov (a tributary of Lake Ladoga), in Rhine in 1995 and invasive in Vistula drainage, coming from Black Sea basin through Prypet-Bug canal (connecting Dniepr and Vistula drainages).
Diagnosis:  Differs from Ballerus ballerus by having small and inferior mouth, 47-54 scales on lateral line, and large eye, about equal to snout length (Ref. 59043).
Biology:  Occurs in fast flowing rivers. Eastern, brackish populations enter the lower reach of rivers for spawning (Ref. 1441). Inhabit large lowland rivers and estuaries. Active at night. Prey on benthic invertebrates. Semi-anadromous populations forage in large brackish-water habitats in estuaries around Black Sea. Spawn in large aggregations in fast-flowing water on gravel bottom or submerged vegetation. Usually rare and threatened due to water pollution (Ref. 59043).
IUCN Red List Status: Least Concern (LC); Date assessed: 01 January 2008 Ref. (130435)
Threat to humans:  harmless


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