Effect of culture temperature on rotifers (<i>Brachionus plicatilis sensu strictu</i>) size and reproduction activities

Abstract

Genus Brachionus of Rotifers is generally used as a live food during the rearing of fish larvae in early stages. However there is limited information on how culture temperature can affect the size and reproduction of rotifers. In this study Brachionus plicatilis sensu strictu (s.s) was selected as a model organism. Ten rotifers were replicated ten times and cultured at stocking density of 1 rotifer/ml at three different temperature 8°C, 21°C and 30°C. Rotifers were fed Chlorella sp. at a level of 1.5 X 10⁶ cells rotifer^-1. Temperature showed a significant effect on rotifers’ size and rotifers’ length ranged from 169 to 275μm. There was also a significant (p<0.001) effect of culture temperature on rotifers lifespan. These results indicate that low temperature prolongs juvenile period and therefore more materials are allocated to body growth. Metabolic activities are high at high temperature and shorten lifespan. The culture temperature showed a significant (p<0.03) effect on number of eggs and juveniles/day. This study has demonstrated that culture temperature has an influence on rotifer’s (B. plicatilis s.s.) size and reproduction activities.

Keywords: Rotifers, Culture Temperature, Size, Reproduction