Settlement of infauna: Larval choice?

Data which support the selective and non-selective settlement of macroinfauna are summarized. Documentation is presented for the following five patterns: (1) gregarious settlement, (2) selection of a site because of the presence of a positive cue other than the presence of conspecifics, (3) no obvious pattern of positive or negative selection, (4) rejection of some types of sites because of the presence of a negative cue and (5) passive entrainment of larvae. All five appear to occur but there are very few examples of each for macroinfauna, and rarely are there supportive data from both the laboratory and the field. Only one example was found for patterns 3 and 4, two examples for pattern 5 and three examples for pattern 1. The relative frequency and dynamics of these patterns should be important in setting the stage for the role of such forces as competition in infaunal assemblages. Unfortunately we need to know more about the prevalence of each of these patterns of settlement as well as their predictability in time and space before concluding that differential settlement, whether passive or active, is more important to benthic dynamics than differential early mortality.