Aspects of the feeding biology and behavior of two parrotfishes (family Scaridae)

Abstract

Aspects of the behavior and feeding biology of two parrotfishes, Scarus jonesi (Streets) and S. gibbus Ruppell, were studied at Eniwetok Atoll, Marshall Islands. A number of adaptations to maximize utilization of food resources and minimize possible physiological stress from ingestion of large amounts of calcium carbonate were examined. Although gut pH of S. jonesi was on the alkaline side of values reported for rays and teleosts, calcium carbonate was inferred to dissolve within pH and time constraints of parrotfish digestion. Observations suggest that acidification of gut contents results from the introduction of slightly acidic bile and possibly from the acidic protoplasm from triturated algal cells.