© 1990 by The Society for Integrative and Comparative Biology
Aquatic Versus Terrestrial Feeding Modes: Possible Impacts on the Trophic Ecology of Vertebrates1
Museum of Comparative Zoology, Harvard University Cambridge, Massachusetts 02138
On the basis of experimental work, a clear dichotomy in design of the feeding mechanism between aquatic and terrestrial vertebrates has been found. The aquatic medium combined with suction and the hydrodynamic tongue offer an unparalleled array of prey capture opportunities for aquatic vertebrates. In the terrestrial feeding model, prey capture and prey processing require a precise functional design to match the nature of the prey. It is proposed that this dichotomy in basic design would result in fundamental differences in the aquatic and terrestrial paradigms in vertebrate ecology. Four hypotheses and their respective supporting evidence are presented: (1) Increased opportunism, more extensive prey switching and food overlap are prevalent in aquatic systems; (2) Convergent evolution which is so pervasive in terrestrial feeding systems is uncommon among aquatic vertebrate feeding systems; (3) Competition is relaxed and character displacement is absent in aquatic vertebrate feeding systems; and (4) Patterns of diversity in aquatic vertebrate feeding systems defy the terrestrial paradigm.