Meeting Abstract

97.2  Thursday, Jan. 7  Octocoral reproductive strategies: Trying to see the forest for the trees? KHANG, S; BENAYAHU, Y; LASKER, HR*; Hawaii Pacific Univ.; Tel Aviv Univ; Univ. at Buffalo hlasker@buffalo.edu

Published and unpublished data were used to characterize the reproductive biology of 175 octocoral species from 73 genera and 22 families. The data set is dominated by shallow water coral reef species, and the distribution of clades across habitats was not uniform. Plexaurids, xenids, alcyonids are all over represented in tropical communities, while taxa such as pennatulids, primnoids and isiids are most common in deep and/or cold waters. Of the species with sexuality reported, 89% of the species are gonochoric and 9% are simultaneous hermaphrodites. Only eight genera (Alcyonium, Sarchophyton, Sinularia, Heteroxenia, Xenia, Acabaria, Paramuricea, and Primnoa) exhibit diversity in sexuality across species. However, those were also the most extensively sampled genera and sexuality was independent of genus. Mapping hermaphroditism on recent octocoral phylogenetic hypotheses suggests independent origins of hermaphroditism in multiple lineages. Of the species with mode of reproduction reported, 40% are internal brooders, 11% are external surface brooders, and 49% are broadcast spawners. Mode of reproduction among these species was related to taxonomic group. Brooding and external brooding are not uniformly distributed among the sampled taxa. The distribution of brooders and external brooders across the Octocorallia suggests that these modes evolved multiple times. Although the finding may be confounded by taxonomic and habitat biases sexuality and mode of reproduction are not independent and gonochoric broadcast spawning species are overrepresented in the data set. In tropical seas gonochoric broadcast spawning species dominate the octocoral fauna, which is a striking and still unexplained difference with scleractinians.