A comparison of the feeding mechanisms of two herbivorous labroid fishes, the temperate Odax pullus and the tropical Scarus rubroviolaceus

Abstract

The osteology and myology of the jaws and pharyngeal apparatus of two herbivorous labroid fishes are described. Odax pullus (family Odacidae) is a temperate-water species, feeding primarily on fucoid and laminarian macroalgae; Scarus rubroviolaceus (family Scaridae) is tropical in distribution and grazes algae from coral and rock surfaces. The intestinal morphology and feeding behaviour of the two species are also described. These observations are discussed in terms of the functional and ecological significance of the morphological differences between these two superficially similar species.