Bigamy or monogamy with maternal egg care in the triggerfish,Sufflamen chrysopterus

Reproductive behavior and mating systems of the triggerfish,Sufflamen chrysopterus (Balistidae), were studied on the fringing reef of Sesoko Island, Okinawa. Both males and females maintained territories against consexual adults, feeding on benthic animals within their own territories. Each male territory overlapped one or two female territories, with mating occurring between the cohabitants. The monogamous males were smaller and foraged more frequently than the bigamous ones, suggesting that the former allocated more energy to growth rather than to improving reproductive success. Pair spawning occurred around sunrise, females only taking care of the demersal eggs until hatching, which occurred around sunset of the same day. On spawning days females foraged less frequently than usual, but as frequently as males. Females spawned at intervals of 5–7 days, usually shifting sites within their territories. Thus both feeding and spawning sites were available for females within their territories, providing males with the opportunity to monopolize females by defending their territories.