Settlement and Recruitment of Pelagic Larvae to Benthic Habitats

Abstract

Many organism that live on the benthos (or bottom) of aquatic ecosystems have biphasic life histories because they reproduce by releasing eggs and sperm in the water column that develop into plankton larvae, which are dispersed by water currents. These populations are considered open systems because postlarval juveniles recruit in regions separate from the adult population. In this article, we present some of the diversity of larval types that have evolved in different organisms. We focus primarily on marine organisms, but include a few examples from freshwater as appropriate. We also discuss the processes that affect the recruitment of new individuals into benthic populations, which involve (i) larval supply, (ii) larval settlement, and (iii) post‐settlement. We note that these processes act over a variety of temporal and spatial scales and we identify the hypotheses that have been presented to explain how variations in these affect recruitment. A large number of processes and hypotheses have been proposed for the settlement and recruitment of pelagic larvae to benthic habitats, which is not surprising given the diversity of organisms involved.