Development and population dynamics of Tisbe biminiensis (Copepoda: Harpacticoida) reared on different diets

The harpacticoid copepod Tisbe biminiensis was reared under controlled laboratory conditions. In order to study the effects of food on larval development and on population dynamics, three diets were tested: the microalgae Nitzschia closterium, Tetraselmis gracilis and a mixture of both algae. The life-cycle parameters were measured, and the demographic variables such as generation time, net reproductive rate, and exponential rate of increase were determined. Results showed that diet affected development and fecundity. Larval development was delayed in copepod fed T. gracilis. The mean number of nauplii per brood was significantly greater in copepod fed the N. closterium diet than those fed the other diets. Survival did not differ significantly between treatments. The exponential rate of population increase ( r) was greater in copepod fed the N. closterium diet (0.49 day −1) and lower in those fed the T. gracilis diet (0.35 day −1). The results showed that although Tis. biminiensis seemed to be able to develop and reproduce on a T. gracilis diet, the diatom N. closterium promoted better results for this copepod in terms of development, fecundity and populational growth rates. The short generation time and high reproductive potential make the use of this copepod promising as live food in aquaculture.