Growth Performance and Egg Ratio of a Marine Rotifer Brachionus rotundiformis Fed Different Diets in Captivity

Abstract

This study was carried out to evaluate the population growth and egg ratio of Brachionus rotundiformis by feeding with three different diets, i.e., live microalgae Nannochloropsis sp., Baker’s yeast, and powdered spirulina. A total of nine conical flasks of 1 L volume were divided into three treatment groups for determining the feeding performance for eight consecutive days. Each experimental group was stocked with B. rotundiformis at an initial density of 10 ind. mL−1. Water temperature, pH, salinity, and light were maintained at (24–29) °C, (7.5–8.5), 30 ppt, and 4000 lx, respectively. Feed was provided twice per day at 9:00 AM and 7:00 PM. The highest mean (±SE) population growth of rotifer was achieved at the end of the culture period (on the 8th day) fed live Nannochloropsis sp. (122 ± 12 ind. mL−1), which was significantly higher compared to the Baker’s yeast and powdered spirulina (p 0.05). The highest mean (±SE) egg ratio of B. rotundiformis was observed in the live Nannochloropsis fed group (0.89 ± 0.01) at the end of the rearing period, which was significantly higher than that of Baker’s Yeast and powdered Spirulina fed group (p < 0.05). Among the three diets, live Nannochloropsis had shown the dietary superiority over Baker’s yeast and powdered spirulina in culturing B. rotundiformis. The results of this study suggest that live Nannochloropsis could be the most suitable diet for the laboratory culture of B. rotundiformis.