Study on biomass culture of freshwater rotifer (Brachionus rubens Ehrenberg 1838)

Abstract

This study was conducted to investigate the most appropriate algae species and concentration for the rotifers Brachionus rubens to the mass culture of this species to provide crucially initial feed for fish larvae. The study was designed with three experiments (three replication) to determine the most suitable micro-algae, micro-algae density and the combination of yeast and algae ratio for best growth of B. rubens.Brachionus rubens were cultured in 1L plastic bottle with an initial density of 50 inds/ml. In the first experiment, suitable micro-algae species was investigated. Rotifers were fed twice daily with Chlorella sp, Nannochloropsis oculata and Chaetoceros calcitrans at 2x106 cells/ml, highest rotifer density (182 ± 3 inds/ml) was found in the group fed Chlorella sp. In the second experiment rotifers were fed with Chorella sp. at 40,000; 60,000 and 80,000 cells/rotifer/day. The results of this experiment showed that rotifers fed with 60,000 cells/rotifer/day performed better with highest density (185 ± 3 inds/ml). Third experiment was designed to replace algae by yeast at a ratio of 1:3, 1:1, 3:1. The highest rotifer density (185 ± 5 inds/ml) was recorded on the fifth day in the 1:1 treatment .