Dietary effects on egg production, egg-hatching rate and female life span of the tropical calanoid copepod Acartia bilobata

Copepods are crucial source of live feeds in the aquaculture industry. In particular, several species of the genus Acartia are considered optimal prey for fish larvae. The species Acartia bilobata has excellent potential for marine larvae culture, as it is easy for mass culture. This study investigated the effects of various algal diets on the egg production and egg-hatching rate of A. bilobata. The results indicated that the single-species diet Isochrysis galbana was the most supportive diet for A. bilobata egg production and female life span in all treatments (egg production: 23.85 +/- 0.70 eggs female(-1) day(-1) and female life span: 18.00 +/- 1.45 days). Nannochloropsis oculata and Tetraselmis chui treatments gave markedly lower egg production and female life span as both single-species and multiple-species diets. For the egg hatching-rate experiment, except for the T. chui treatment, which yielded a considerably lower hatching rate than the other diets, the hatching rate was only slightly affected by the algal diets. These results confirm that A. bilobata, a tropical brackish-water copepod species, develops rapidly at 28 degrees C and can produce a large number of eggs; therefore, it has considerable potential for larvae culture.