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).