Density effects on a tropical copepod Acartia sp.: implications as live feed in aquaculture

Abstract

Calanoid copepod Acartia species are major live feeds for the early stages of economically important marine fish in hatcheries in Southeast Asian countries. However, rearing Acartia copepods at high densities to increase productivity remains a major challenge. To address the issue, we conducted two experiments on 1) Acartia sp. nauplii (1000, 3000, 6000, 9000, 12000, and 15000 individuals L-1) and 2) adults (1000, 1500, 2000, and 2500 individuals L-1). We assessed key parameters for biomass production: development, survival, and egg production. In general, increased density resulted in longer development time, and lowered survival and egg production, but did not affect the size of adult males and females. Despite survival to adulthood decreasing at higher stocking nauplii densities, the number of surviving adults was highest at a stocking density of 12000 ind L-1. Egg production was very low which may be the result of high egg predation. The total eggs harvested were highest at the lowest adult density. These results are essential for the biomass production of Acartia sp. in central Vietnam.