Correlates of reproductive success in a wild population of Hippocampus whitei

Abstract

An analysis of 27 broods born in situ to wild male seahorses Hippocampus whitei, with known partners, showed that female size was the key determinant of the number of young released by the male. There was also an apparent decline in both the number of young per brood, and the size of those young, over the breeding season. The size of the brood and of the young may be more proximate indicators of reproductive success in seahorses than in other fishes, because they can be measured at the time of release, here 20–22 days after fertilization, after which survival is presumed to be relatively higher than in other species. The best model, however, explained <40% of the brood size.