Courtship, spawning and inferred social organization of American angelfishes (Genera Pomacanthus, Holacanthus and Centropyge; pomacanthidae)

Courtship, spawning and social organization are described for six species of American angelfishes, with notes provided on three additional species. In all species discussed, as well as all those in the western Pacific for which data are available, spawning occurs daily, throughout all or most of the lunar cycle, and involves pairing only. Both permanent sexual dichromatism and temporary dichromatism during courtship and spawning occur sporadically in the family and do not yet clearly correlate with any specific social regime. Sexual size dimorphism (males larger than females) is manifest by the genera Centropyge, Genicanthus, Holacanthus, and possibly Pomacanthus. Although protogynous hermaphroditism is documented for some angelfishes, it may be premature to conclude this for all, given the highly variable nature of their grouping. Social organizations vary from apparent monogamy (Pomacanthus paru) to male-dominated harems (Holacanthus ciliaris, H. tricolor, Centropyge argi) and to apparently promiscuous explosive breeding assemblages (Pomacanthus arcuatus) and a lek-like system (Holacanthus passer). Variation within some species may be as extreme. This flexibility suggests that selective pressures may not be unidirectional over a species' entire range. Consequently, manifested characteristics may vary geographically or may be some compromise determined by the degree of population panmyxia and the number and fecundity of individuals in each selective regime.