A preliminary study of development of the buccal apparatus in Pomacentridae (Teleostei, Perciformes)

Abstract

AbstractThis study compares, in five species of Pomacentridae (Chromis viridis, Dascyllus flavicaudus, Chrysiptera glauca, Pomacentrus pavo, Plectroglyphidodon lacrymatus), the changes in cephalic skeletal structures between settling larvae and adults living on the reef. Variations were studied in the suspensorium, the opercle, the mandible, the premaxillary bone and the teeth. Comparisons of the feeding apparatus enabled two different types of feeding to be distinguished in adults: suction feeding and grazer sucking. Adult C. viridis and D. flavicaudus have a high suspensorium, a well-rounded mouth during jaw opening and caniniform teeth. These two species can be considered to be suction feeders. On the other hand, adult C. glauca, P. pavo and P. lacrymatus have less developed suspensoria, opercles and ascending process of the premaxillar, and present incisiform teeth. These three species appear to be grazer suckers. However, the larvae of all five species present an unimodal way of feeding, defined as ram-suction. Differences between larvae and adults appear clearly to be related to their ecology. The increasing variation presented in feeding apparatus during the settlement phase could be linked to diversification leading to occupancy of different ecological niches.