SPATIAL PATTERNS OF SPAWNING IN THE CORAL-REEF DAMSELFISH DASCYLLUS-ALBISELLA

Reproductive patterns of the endemic Hawaiian damselfish Dascyllus albisella were examined around the island of Oahu for 5 m in 1992. Daily variation in spawning was studied at four spatial scales: individual territories; reef transects; whole patch reefs; and locations separated by >20 km. A 6 d, non-lunar nesting cycle was found for individual males, and a synchronized, 6 d, non-lunar spawning cycle was found within reef transects, whole patch reefs, and locations. Spawning synchronicity was maintained among reefs within a location. However, spawning among locations was found to be asynchronous, limiting the spatial scale of reproductive synchrony to >1 km but <20 km. Inherent benefits of synchronous reproduction are discussed for D. albisella, but only the localized swamping of planktonic predators may be an inherent benefit of synchronous spawning for this species. Alternatively, synchronous spawning among populations may exist from adults tracking local, favorable environmental conditions rather than having evolved towards an inherent benefit of synchronization.