Ecological differences between hamlet (Hypoplectrus: Serranidae) colour morphs: between-morph variation in diet

Dietary differences between hamlet Hypoplectrus spp. colour morphs were examined in fishes from Puerto Rico, U.S. Virgin Islands, Curacao, Honduras and Belize. Hamlet diet across all countries was characterized by large overlap between most colour morphs in both the proportion and numbers of dietary items consumed, although some differences between morphs were apparent. Indigo hamlets Hypoplectrus indigo were the only morph to consume fishes (blue chromis Chromis cyanea and sunshinefish Chromis insolata ) almost exclusively. The sympatric occurrence of other ecologically indistinguishable colour morphs, however, suggests that divergent ecological selection alone cannot explain population divergence in hamlets. Geographical variation in diet was also observed within black Hypoplectrus nigricans and yellowtail Hypoplectrus chlorurus hamlets which may reflect geographical differences in prey availability or differences in prey choice.