IN VITRO EFFECTS OF SALINITY AND ALGAE GENERA ON THE ROTIFER (BRACH ION US PLICATILIS MULLER 1786)

The marine rotifer Brachionus plicatilis is extensively used as a major live food in fish larvae culture all over the world. In the present study an attempt was made to find out the optimum salinity and feeding conditions for growth of the rotifer B. plicatilis. The rotifer was cultured using Batch culture method at four salinities ranges (20, 25, 30 and 35ppt) and was fed with 3 species of microalgae including, Nannochloropsis oculata, Isochrysis galbana and Chlorella sp. The difference between salinity was not significant (P>0.05) but there was a significant difference between the food types (P<0.05). In all of the experiments, the combined effect of salinity and algal type on rotifer growth were significant (P<0.05). The best result was observed in the experiment conducted at 35ppt salinity using N. oculata as the main food (378 ind/ml).