spawning aggregations of tropical reef fishes provide spectacular examples of the diversity of reproductive strategies of coral reef organisms. despite the presumptive importance of such aggregations, little has been published regarding the biology or oceanography of these phenomena. what actually constitutes a spawning aggregation has been defined based only on the limited perspective of studies of individual,or at most, a few species. with the exception of the siganidae, reef fishes with spawning aggregations all produce planktonic eggs. this factor alone eliminates more than half of reef fish species, including the highly diverse Gobiidae, Blennidae, Pomacentridae and others. what is left are mostly larger species; even among those, relatively few are presently known to aggregate to spawn.