ABSTRACT
This chapter presents information on recruitment in echinoderms and examines variability in recruitment. Recruitment means addition of new individuals to a population and may be by immigration or reproduction. Mass mortality or highly successful recruitment could be due either to biotic or abiotic factors. It is not at all clear whether biotic rules are dominant or whether physical and chemical components outside of the homeostatic abilities of populations give rise to variation in recruitment. Information on recruitment is available for all extant echinoderm classes except crinoids. A latitudinal cline of recruitment is shown by another eastern North Pacific echinoid. Recruitment of Strongylocentrotus purpuratus varies with intertidal position. At Sunset Bay, Oregon, based on the percent contribution of the 1963 year class, there were more recruits high in the intertidal than at the lowest stations. Small scale variation in recruitment also has been shown forLytechinus variegatus in Puerto Rico.
