Effects of microalgal diet on the population growth and fecundity of the cyclopoid copepod Paracyclopina nana

Abstract This study investigated the effects of seven microalgal diets, including single‐species diets of Rhodomonas salina (R), Tisochrysis lutea (T), and Pavlova lutheri (P), two‐species diets (R + T, T + P, and R + P), and a three‐species diet (R + T + P), on the cyclopoid copepod Paracyclopina nana growth, stage composition, and ovigerous female size and fecundity. Experiments were conducted in 10‐L beakers starting with nauplii from a 300‐L culture population. After 15 days of feeding, the R + T diet induced the greatest total population growth, particularly for copepodites and all female stages (preadult females, females, and ovigerous females). The R diet followed by R + T also generated the greatest individual size and clutch sizes in ovigerous females. Overall results show that the diets leading to the highest total population growth and clutch sizes in P. nana included R. salina. Conversely, P. lutheri was not a very effective microalga to enhance P. nana productivity in culture. Current results are the first to show that R. salina is a suitable microalga for production of P. nana for use as live food for marine fish larval aquaculture.