Effect of food composition on egg production and hatching success rate of two copepod species (<i>Calanoides carinatus</i> and <i>Rhincalanus nasutus</i>) in the Benguela upwelling system
We have analysed the daily egg production (EPR) and hatching success rates of the calanoid copepods Calanoides carinatus and Rhincalanus nasutus as a function of nano- and microplankton concentration and composition in the northern Benguela upwelling system off Namibia. Food concentration explained 55% (R. nasutus) to 62% (C. carinatus) of the EPR variability. We found no relation between the residuals of the food concentration–EPR regression and the percentage of the different taxonomic components of the nano- and microplankton. Nor was there a relation with the proportion of the diatom Skeletonema costatum that dominated the major blooms or with the number of nano- and microplankton species. We conclude that food quality differences could not be attributed to the relative composition of microplanktonic particles of the different groups (i.e. taxonomic composition)
