Evaluation of diets for culture of the calanoid copepod Gladioferens imparipes

Provision of copepod nauplii as food increases larval survival in many fish species that are difficult to rear using standard practices. Gladioferens imparipes is a temperate estuarine calanoid copepod with culture potential. Diets were tested to determine which would maximise copepod production. Copepods were fed five diets: Isochrysis galbana, Chaetoceros muelleri, Dunaliella tertiolecta, Nannochloropsis oculata and baker's yeast. Copepod survival, time to maturity, maturation rate, nauplius production and female length were recorded at 20°C and 25°C. By most criteria, Isochrysis was the most efficacious diet, followed by Chaetoceros and then Dunaliella. Nannochloropsis and yeast resulted in little or no survival. Fatty acid profile of each diet was determined. In general, copepod production was positively related to the ratio of DHA:EPA in their diet. Poor survival on Nannochloropsis was probably a result of the small cell size and poor digestibility of this species.