GROWTH AND SURVIVAL OF BROWN TROUT FRY (SALMO TRUTTA M. FARIO L.) IN THE WILD, REARED IN THE HATCHERY ON DIFFERENT FEED

摘要

The paper shows the results of different types of food used in rearing and the impact of the food on the further survival and growth of brown trout fry (Salmo trutta m. fario L.) in the wild. Rearing of larvae was conducted in three groups: 1) zooplankton-fed group, 2) chironomids-fed group and 3) pellet-fed group. During the rearing period, the pellet-fed group reached the greatest SGR value – 4.25% day~(-1), while the zooplankton-fed group reached 4.25% day~(-1). The chironomid-fed group were characterised by the lowest SGR value (1.94% day~(-1)). In the wild, the zooplankton-fed group achieved the greatest rate of survival (60%) and high data of SGR (2.23% day~(-1)). The zooplankton-fed group's survival and growth rate was higher than the pellet-fed group survival (38%) and SGR (1.87% day~(-1)). In the wild, the chironomid-fed group reached the lowest rates of survival (23%), but the fork length and weight results were not different in comparison to the zooplankton-fed group. Moreover, the SGR result of this group was the highest – 2.55% day~(-1). We stated that rearing of brown trout larvaeon live zooplankton had a positive effect on survival and growth of brown trout fry in the wild.