Copepod egg production in the western Mediterranean: Response to food availability in oligotrophic environments

Egg production rates of the copepods Centropages typicus, Clausocalanus lividus and Temora stylifera were determined in the temperate oligotrophic western Mediterranean during late spring and early summer. Egg production appeared to be severely limited and related to the concentration of >5 μm chlorophyll. Although phytoplankton can partially explain the observed gradient in egg production from coastal waters towards the open sea, it is not sufficient to explain the recorded egg production rates, and other non-pigmented items (microzooplankton) must be important components of the copepod diet. Copepod growth rates appeared uncoupled to the pattern in copepod abundance from coastal to oceanic waters, suggesting the role of other factors such as predation or advection in determining their distribution.