Reef coral reproduction in the Abrolhos Reef Complex, Brazil: the endemic genus Mussismilia

The current contribution deals with the reproductive biology of a genus end emic to Brazil Mussismilia Ortmann, 1890 - including all three species of t he genus: M. braziliensis (Verrill, 1868), M. hartti (Verrill, 1868), and M . hispida (Verrill, 1902), which occur sympatrically in the studied area, t he Abrolhos Reef Complex, Brazil. Sexuality patterns, modes of reproduction , synchrony and spawning periods are reported, and were determined by histo logical examination of material. All three species started to develop femal e and male gametes over different periods in the same breeding season. The three species are probably broadcast spawners, since no embryos or planulae were observed in any species at any given time of the year. Each reproduct ive cycle lasted approximately 11 months. Oogenesis and spermatogenesis sta rted in different periods, with spermaries appearing in approximately the e ighth month of ovary development and lasting about 3 months. Reproductive c ycles were annual. Spawning probably occurred in consecutive months in each species. In M. braziliensis, spawning presumably happened between March an d the middle of May in 1996 and 1997. Evidence suggested that spawning even ts of M. hispida took place between the end of April and mid-June. M. hartt i may have spawned between September and November. The data presented here suggested that all studied species have at least one exclusive spawning per iod, asynchronically with the others. A possible exception may be the simul taneous (or close) spawnings of M. braziliensis and M. hispida in May. It i s suggested that asynchrony in spawning periods among species may reduce th e chance of hybridization, gamete waste and the competition for settlement surfaces. The occurrence of extended spawning periods for each species may also reduce the risks of reproductive failure, due to temporary adverse con ditions.