Vertebrate herbivores in marine and terrestrial environments: A nutritional ecology perspective

The study of digestive physiology provides a framework for analyzing food r esources, feeding patterns, and evolutionary trends in vertebrate herbivore s. Most of the research in this field, nutritional ecology, has been focuse d on terrestrial herbivores, especially mammals. By integrating physiologic al, demographic, and evolutionary approaches, the study of terrestrial herb ivores has generated several important hypotheses, notably on factors deter mining body mass. Marine vertebrate herbivores are abundant and locally div erse, but with the exception of reptiles and mammals, we lack information o n digestive physiology and processing of plant foods, the key element in te rrestrial studies. This review provides a foundation for a nutritional ecol ogy of marine vertebrate herbivores, especially teleost fish, by summarizin g the available information on their digestive physiology and identifying r esearch priorities in the field.