Vulnerability of fish eggs and larvae to predation: Review of the influence of the relative size of prey and predator

We investigated the potential influence of relative body size of early life stages of fishes on their vulnerability to predation by crustaceans, ctenophores, medusae, and fishes and contrasted the patterns with predictions based on different conceptual models. We found that vulnerability of ichthyoplankton to predation by ctenophores and by predatory fishes is dome shaped. Laboratory estimates of predation rates of these two predator types were negatively influenced by the volume of the container in which the experiments were conducted and by the duration of the experiment. Medusae and crustaceans showed decreasing predation rates with increasing relative size of fish larvae. Laboratory estimates of predation rates of medusae were influenced by container volume, temperature, and duration of the experiment whereas predation rates of crustaceans were influenced by container volume alone. Independent of predator type, the vulnerability of ichthyoplankton to predation was maximal when fish larvae were 10% of the length of the predator.