Abstract
In common with other Faviidae, Favites abdita and Leptoria phrygia on Heron Island reef, Great Barrier Reef, Australia, are simultaneous hermaphrodites with ovary and testis in the same mesentery. During the annual gametogenic cycle oogenesis precedes spermiogenesis by several months. Both species exhibit synchronous spawning; gonads are released intermingled in positively buoyant compact spheres. Because of this it is believed that external self- and cross-fertilization occur in these species. Both species are present, but not abundant, in shallow and deeper water on the reef. Their mode and timing of spawning may largely confine propagule dispersal to the home reef, but not to any specific habitat within the reef. The release of eggs and sperm may be the most common method of sexual reproduction in Scleractinia.