Integration of versatile functional design, population ecology, ontogeny and phylogeny

The study of the functional morphology of fishes has been greatly influence d by interactions with related fields. We give examples of some possible co nfounding factors when trying to assess the functional repertoire of fishes , including the effect of prey availability and the effect of captivity. A narrow range of prey items and an extended period in captivity both decreas e the scope of the functional repertoire. Specialists and generalists have not been able to coexist in conventional competition based models of optima l foraging. A recent extension of this model does succeed in modeling the c ommunities which are typical of the African Rift Lakes. This warrants a re- evaluation of the importance of competition in structuring fish communities . Ontogenetic shifts in the functional morphology of the feeding apparatus of teleostean fishes may explain why a synapomorphy of the group is not alw ays important functionally in the adult. The levator operculi-opercular rot ation mode of mouth opening is viral for larval fishes bur in some cases be comes unimportant in adults. We emphasize that examination of early life hi story stages holds important information about the adaptive significance of diverse structures.