A study on the adaptation and feeding of wild-caught flounder juveniles in aquaculture conditions

In this study, the growth and survival rates of wild-caught flounder (Platichthys flesus) reared with different feeding methods and their adaptation to culture conditions have been investigated. The experiment lasted 62 days and a total of 57 fish with an initial mean weight and length of 0,37g and 3,37cm respectively, were used. The experiment was carried out in 3 aquariums with sand substrates. The fish were starved for 2 days and 3 treatments were assigned: treatments I and II received live zooplankton as a first feed whereas treatment III received dry pellets through out the experimental period. The main difference between treatments I and II was the timing of dietary switch from live zooplankton to moist feed followed by dry pellets. Fish in treatment III did not initiate feeding on dry pellets by day 22 and 100% mortality was observed. Fish in treatment II, which received a dietary switch from moist feed to dry pellets on day 33, had a higher mortality rate (42%) compared to that of fish (37%) in treatment I which received a dietary switch from moist feed to dry pellets on day 43. At the end of the experiment, the live weight and length of fish in treatment I were 0,82 +/- 0,236 g and 4,52 +/- 1,286 cm respectively, whereas the live weight and length of fish in treatment II were 0,86 +/- 0,259 g ve 4,69 +/- 1,272 cm. The live weight increases were calculated as 127 and 132% for treatment I and II, respectively. It was concluded that wild-caught juvenile flounder can be adapted to culture conditions when fed incombination with live zooplankton and moist feed followed by a gradual switch from moist feed to dry pellets.