Role of Encapsulation in Invertebrate Life Histories

Abstract

Many benthic marine invertebrate species have mixed life histories, in which larvae emerge into the plankton to continue their development after a relatively short period of encapsulation. In such cases, the benefits of encapsulation are not obvious and are considered here. A simple probability argument is constructed which suggests that even a short period of encapsulation can significantly reduce mortality during mixed development if daily mortality rates in the plankton are below some critical level. Survival benefits of even short periods of encapsulation would be augmented further if free-living larvae were less susceptible to mortality than were free-living embryos. Encapsulation may reduce developmental mortality in mixed life cycles simply by retaining developmental stages until they are better able to avoid planktonic and benthic predation.