Biology

Inhabit lower reaches of rivers, coastal lakes, estuaries, and open sea. Occur close to surface and tolerate salinities up to 12 ppt at the sea. Adults predominantly prey on planktonic crustaceans, terrestrial insects, and small fish. Larvae and young juveniles feed on zooplankton, algae, and insect larvae. Undertake migration for long distances, up to upper reaches of streams in piedmont and montane zones. Spawns in rivers or streams with heavy current on gravel bottom. Landlocked population breeds in reservoir tributaries. Adults migrate back to the sea soon after spawning to forage while young juveniles move downriver in autumn of same year or next spring. Commonly hybridizes with Squalius cephalus. Populations sharply declined in the early and middle 20th century due to the constructed dams that hindered in reaching the spawning grounds. Remaining populations spawn below these dams (Ref. 59043).