Contrasts in algal food processing among five herbivorous coral‐reef fishes

There were significant differences among five sympatric herbivorous reef fish species in their ranking of seven food‐processing characters. Between them Zebrasoma scopas and Stegastes nigricans had the lowest bite rates, longest filling times, lowest defaecation activities and slowest gut turnover. Acanthurus nigrofuscus and Scarus sordidus were similar in having the fastest filling times, and high bite rates, gut‐contents masses, gut turnover and defaecation activities. Ctenochaetus striatus was intermediate between those species pairs in five out of seven characters. Rich algal diets of S. nigricans and Z. scopas were contrasted with the carbonate intake of S. sordidus. The food‐processing pattern of C. striatus was related to the siliceous content of a diatom diet. Food‐processing characteristics of A. nigrofuscus were attributed to a diet which is readily absorbed and/or is of high nutritional quality.