FEEDING ECOLOGY OF SPOTTAIL PINFISH (DIPLODUS-HOLBROOKI) FROM AN ARTIFICIAL AND NATURAL REEF IN ONSLOW BAY, NORTH-CAROLINA

The purpose of this study is to compare diet composition and sources f or spottail pinfish (Diplodus holbrooki) from adjacent innershelf arti ficial and natural reefs located 8 km offshore in Onslow Bay, North Ca rolina. Different size classes of spottail pinfish, season of capture (spring or summer), and prey habitat (hardbottom, softbottom or plankt onic) were compared for each reef. Spottail pinfish had an overall omn ivorous diet of 50% benthic algae, 30% benthic animals, 15% planktonic animals and 5% miscellaneous animal prey, by volume. Seasonal variati on in diet was apparent. More planktonic food items and crustaceans we re eaten in the spring and diet shifted to include more algae and bent hic foods in the summer. There was no difference in the amount of alga e eaten by fish of different size classes though larger fish consumed less planktonic foods and smaller fish consumed more benthic foods. Th e diets of 96 spottail pinfish (60-160 mm SL) at the artificial and na tural reef show 88% similarity. While some food items (bryozoans, amph ipods) differed significantly between reefs, the proportion of prey ty pes (benthic animal, algae, planktonic animal) in the diet were not di fferent overall between reefs. Prey associated with softbottom habitat s were a minor (<1% total diet) part of the diet.