Sexual reproduction in solitary corals: Overlapping oogenic and brooding cycles,and benthic planulas in Balanophyllia elegans

The temperate solitary coral Balanophyllia elegans Verrill, 1864 was collected monthly between January 1977 and August 1978 off the California coast. B. elegans reproduces only sexually, is gonochoric, and broods its embryos. Males are ripe only in late summer, but oocytes and embryos (ca. 40 per female) are found throughout the year. The presence of oocytes and embryos throughout the year may be the result of very long, overlapping oocyte growth and embryonic developmental times. Large, crawling, benthic planulas are released mainly in the winter. The skeletal design of the corallum of B. elegans accommodates the brooding of unusually large embryos; this design may be indicative of brooding large embryos in other species of corals, particularly dendrophyllids.