Spawning synchrony in scleractinian corals: Comment on Mangubhai & Harrison (2008)

Mangubhai & Harrison (2008; Mar Ecol Prog Ser 360:85–96) documented spawning patterns in an equatorial assemblage of Acropora spp. in Kenya over a 2 yr period. They concluded that reproductive seasons are more protracted at low latitudes and that ‘mass spawning’ does not occur in equatorial regions, due to a breakdown in spawning synchrony among species. However, this interpretation hinges on the authors’ distinction of ‘mass spawning’ from ‘multi-specific spawning’ for which they provide no ecological rationale. Moreover, they did not cite recent studies that document spawning in synchrony by numerous species in equatorial assemblages. In addition, the authors overlooked work demonstrating that spawning is not as synchronous as typically portrayed on the Great Barrier Reef or in Western Australia. In the context of that literature, reproductive patterns of Acropora spp. in Kenya are more similar to sub-tropical reefs in southern Australia rather than to other equatorial reefs. We conclude that the study of reproductive synchrony in corals is being impeded by the lack of a consistent definition that would make it possible to quantify and compare patterns of synchrony at both population and assemblage scales.