Effects of adult stocking density on egg production and viability in cultures of the calanoid copepod Acartia tonsa (Dana)

The effect of stocking density of the calanoid copepod Acartia tonsa was evaluated in a 96 h rearing experiment. Possible density-dependent egg production and egg viability were analysed at stocking densities of 100, 200, 300, 400 and 600 adults L-1. Temperature, oxygen saturation and algal concentration were kept optimal. A non-density-dependent mortality rate of 15-19% day(-1) was documented. A non-significant density-dependent egg production was observed between 100 and 600 adults L-1. The average egg production was 22.5 +/- 8.8 egg female(-1) day(-1) in all densities. The average egg hatching success was 84.7 +/- 4.8% and was never observed below 76.1%, with no significant differences across the stocking densities. Conclusively, as a practical recommendation for the aquaculture industry, copepod cultures with densities ranging from 100 to 600 adults L-1 and presumably even more dense cultures are possible with the studied species obtaining a steady egg production and still high egg viability.