Effects of food concentration on the development, survival, reproduction of calanoid copepod (Pseudodiaptomus dubia)

An experiment was carried out to evaluate effects of food concentration on the development, survival, reproduction of a calanoid copepod (Pseudodiaptomus dubia), in which the population life table was formed at different food concentration. The animals were fed with Chaetoceros muelleri as food designated with five food concentrations, 0.5×10⁵, 3×10⁵, 6×10⁵, 12×10⁵ and 17×10⁵ cells/mL, respectively. The results showed that different concentrations of C. muelleri had significant effects on the development, survival and reproduction of P. dubia. When the food concentration was 3×10⁵ – 6×10⁵ cells/mL, the development time, growth rate and hatching rate of P. dubiawas 174–192 h, 0.6–0.64 μg C/d, and 464.2–608.2 neonates per female, respectively, which were significantly higher than those of the lowest concentration (0.5×10⁵ cells/mL) and the highest concentration (17×10⁵ cells/mL). The survival and lifespan decreased with the increase of food concentration. The survival of P. dubia reached up to 80% when the food concentration ranged from 0.5×10⁵ cells/mL to 6×10⁵ cells/mL, which were significantly higher than that of the 12×10⁵ and 17×10⁵ cells/mL. When the food concentration was 3×10⁵ – 6×10⁵ cells/mL, the intrinsic growth rate of P. dubia was 0.237/d and 28%–32% higher than that of 0.5×10⁵ and 17×10⁵ cells/mL. Therefore, putting too much or too little food would be disadvantageous to the population growth of P. dubia. Therefore, the most favourable food concentration for P. dubia would range from 3×10⁵ to 6×10⁵ cells/mL.