Mirela Mocanu (Creţu)


THE INFLUENCE OF DIFFERENT STOCKING DENSITIES ON GROWTH PERFORMANCES OF ONCORHYNCHUS MYKISS (WALBAUM, 1792) IN A RECIRCULATING AQUACULTURE SYSTEM

Mirela Mocanu (Creţu), V. Cristea, Lorena Dediu, D. Desimira, Angelica Docan, T. Ionescu

Abstract
The purpose of this experiment was to evaluate how stocking density influence the growth performance of juvenile rainbow trout (Oncorhynchus mykiss) reared in a recirculating system. The experiment took place over a period of 33 days. A number of 254 rainbow trout with an average weight of 29,51 1,32 g were divided into four rearing units in order to create different stocking densities: in B1-2,64 kg/m3, with an average weight of 31,68 g/ex, B25,16 kg/m3 with an average weight of 30,39 g/ex, B37,12 kg/m3 with an average weight of 28,52 g/ex and B4-9,42 kg/m3 with an average weight of 27,46 g. At the end of the experiment specific growth rate (SGR) calculated in B1 variant was 2,84% (g/day), in B2-3,36% (g/day) B3-3,20% (g/day) and B4-3,13% (g/day).The results of the experiment proved high technological plasticity in all the four variants. In particular, regarding the performance indicators, it has been observed that they are not influenced by the level of the stocking density. This fact concludes that the species approached in the study (Oncorhynchus mykiss) presents a high level of interest for the growth in recirculating systems of industrial aquaculture with a high level of intensity.

Key words: rainbow trout, recirculating aquaculture system, stocking density, tehnological performance indicators