The reproductive seasonality and fecundity of yellowtail clownfish (Amphiprion clarkii) in the Philippines

Understanding the spawning patterns and egg production of clownfish is important for understanding their life history and the factors contributing to population persistence. The egg production and temporal spawning patterns of eight breeding pairs of yellowtail clownfish, Amphiprion clarkii (Bennett, 1830), were observed for a 14-mo period on a coral reef off the Central Visayas, Philippines. Spawning events and egg production revealed a peak breeding season from November through May, which coincides with temperatures below 30 °C. Noticeably fewer spawning events and smaller clutch sizes occurred during the warmer months (30–31.5 °C) of June through October. Within the spawning season, egg production increased weakly leading up to the new moon and decreased after the full moon. The seasonality of spawning events found in our study were comparable to those of clownfish in temperate regions, and surprisingly unlike findings from other tropical latitudes and climates. These findings suggest that recruitment and larval dispersal in this population will be most sensitive to oceanographic conditions during relatively narrow periods of time each year.