ON THE DIETS OF CALANOID COPEPODS

A review of the literature (ca 1900 to 1992) on copepod feeding indica tes that combinations of stochastic and deterministic processes result in behaviors, or feeding strategies, that optimize nutritional gain f rom the food environment, and further, that strategies change in respo nse to environmental variability. Because the diet is the product of a feeding strategy, one may gain insight into the ways in which copepod s respond to their food environments by measuring their diets. Investi gations of the links between copepod feeding and production suggest th at dietary diversity is often a key to the procurement of a nutritiona lly complete ration, and the optimization of secondary production with in constraints dictated by the physical environment. The ability to ea t different kinds of foods (omnivory) and the tendency to include a va riety of foods in the daily ration may enhance the probability of obta ining a nutritionally complete ration in variable, nutritionally dilut e, food environments. The notion that the relationship between feeding and production in copepods is driven by dietary diversity is derived in part from a recent recognition of the diversity of microplanktonic organisms that potentially or actually contribute to the diet. Further , the concept is consistent with current trophic dynamic models in whi ch food webs are envisioned as complex interwoven systems rather than short, simple chains.