ABSTRACT
Herbivorous fishes constitute a small proportion of the total diversity of marine fishes. It is widely recognized that many more herbivorous species exist in tropical waters as compared to temperate waters. M. H. Horn concluded that temperate herbivorous fishes achieved densities as high as those of tropical species primarily during the summer months, but that the temperate species become more omnivorous in their food habits and move offshore during the winter. The most important herbivorous cyprinids are the Chinese carp as well as some of the Indian carp belonging to the two genera Labeo and Cirrhinus. Herbivorous fishes can be classified regarding their feeding behavior as browsers, grazers, and filter feeders. The alimentary tract of herbivorous fishes shows great structural diversity, which is due to the different digestive mechanisms existing among these fishes. White states that the relative shortage of available nitrogen is the major factor influencing the abundance of all herbivores.
