Ontogenetic Shifts in Resource Use and Shoaling Tendency Related to Body Size in Red Sea Goatfish (Parupeneus forsskali, Mullidae)

Abstract. Red Sea goatfish show marked behavioral differences related to body size in food searching, substrate use, and shoaling tendency. While smaller fish mainly use their barbels to search for food hidden in the upper sediment layers or in crevices of corals, the largest fish frequently burrow with their mouths in deeper layers of the sediment. The conspecific shoaling tendency decreases with increasing size. Only smaller-sized fish are found in mixed-species shoals. The data are discussed with regard to the relations between ontogenetic changes in body size, resource utilization, and socialization patterns.