9521093 Shanks The size of an adult population of a marine invertebrate is in part the result of factors affecting the mortality of their planktonic larvae. In this study the importance of natural predation to the survival of these meroplankton will be assessed with in situ experiments that seek to test three hypotheses: 1) larval mortality rate varies directly with the concentration of planktonic predators, 2) "background" plankton significantly influences predation rates, and 3) morphology and behavior of meroplankton contribute to interspecific variation in predation rates. ***