TROPHIC INTERACTIONS BETWEEN COPEPODS AND MICROPLANKTON - A QUESTION ABOUT THE ROLE OF DIATOMS

Relationships among microplankton composition, copepod diet, and egg production are examined with data from gut content analysis of copepods from California coastal waters and from the Irish Sea, feeding and egg production experiments on Acartia tonsa off southern California, and egg production measurements on copepods from a subtropical estuary (Port Everglades, Florida), temperate shelf waters (southern California, Irish Sea), and the open ocean (Gulf Stream). The copepod species studied appeared to feed preferentially on dinoflagellates and microzooplankton relative to diatoms. Patterns of variability in egg production conform, generally, to changes in dinoflagellate and microzooplankton biomass, but seem to be independent of changes in diatom biomass.