Effect of diatom and dinoflagellate diets on egg production and ingestion rate of Centropages furcatus (Copepoda: Calanoida) from subtropical bay (Bahía de la Paz, Gulf of California)

Abstract

This study experimentally determined the role of local diatom and dinoflagellate diets and their fatty acid composition on the survival, in gestion, and egg production rates of the copepod Centropages furcatus from Bahía de La Paz. The fatty acid profiles of the diatoms Odontella longicruris and Chaetoceros sp., and of the dinoflagellates Scripp siella sp., Gyrod nium sp., and Prorocentrum m cans were deterined. After in cubating at 24 °C in darkness during 24 h, survival within all phytoplankton diets was > 90%. Dinoflagellate diets providedhig her egg production (>25 eggs fe ma le-1 day-1) than diatom diets (<10 eggs female-1 day-1). No significant differences were observed in the in gestion rates when feddinoflagellates or diatoms, which varied between 400 and 900 ng C copepod-1 h-1. Hig her egg production with dinoflagella te diets suggests better food quality, which may be attributed to hig her proportions of the fatty acids 18:4 (n-3) and 22:6 (n-3). These results suggest that when C. fulcatus predominantly graze on dinoflagellates egg production will increase. Hig her abundances of dinoflagellatesin the La Paz bay could be cou pled with hig her egg production of the copepod C. furcatus.