An experimental study on food and salinity preferences of two Brachionus plicatilis rotifer strains from Iran

Abstract

Effects of feeding on four algal species (Chlorella vulgaris, Nannochloropsis oculata, Isochrysis galbana and Scenedesmus obliques) at salinities of 5, 15 and 25 on the population growth parameters of two Iranian strains of the widespread rotifer species Brachionus plicatilis were examined. Maximum specific growth rate of 0.55 ± 0.02 day^-1 and final population density of 7 961 ± 3 267 ind. ml^-1 were observed in the Ba strain fed with Chlorella at a salinity of 15. The minimum population density of 10 ± 0 ind. ml^-1 occurred in the Ba strain fed with Scenedesmus at a salinity of 5. There were significant differences in the egg ratio (number of eggs . number of females) between the two rotifer strains when fed with Scenedesmus at a salinity of 15. Multivariate post hoc comparisons demonstrated the significant effects of algal species on all estimated parameters in both rotifer strains and the significant effects of salinity and salinity x algae on specific growth rate and population density of the Ba strain.

Keywords: algae, population growth

African Journal of Aquatic Science 2012, 37(1): 101–106