Physiological State of Atlantic Salmon (Salmo Salar L.) and Sea Trout (Salmo Tutta Trutta L.) Fry Grown in the Žeimena Hatchery

Physiological states of Atlantic salmon (Salmo salar L.) and sea trout (Salmo trutta trutta L.) fry from the Žeimena hatchery were compared in 1999 and 2000 using a complex of biological parameters. Sea trout fry from the Žeimena hatchery were characterised by a smaller mean body length, mean body mass, and a lower body mass/length ratio as compared to salmon. In June, the condition factor and liver somatic indices of salmon and sea trout were significantly higher than those found in November. These changes in morphophysiological (condition factor, liver somatic index) parameters indicate that biotechnological processes of fish production during the hatching period until June were not optimal. In autumn all biological parameters of fry of both species were found to be characteristic of healthy fish with higher possibilities for life in natural waters.