Table 4. Gut contents of 21 spottail pinfish collected from the jetty at Radio Island, NC, on 1 September 

 1984. Prey abundance rankings are for the jetty and are subjective. Rare = very difficult or impossible 

 to find. Common = small or isolated individuals can be collected but a kilogram of the material would be 

 difficult or impossible to collect in an hour. Abundant = a kilogram could be collected easily in only a 

 few minutes. 



unpalatable brown seaweeds such as 

 Sargassum , Padina , and Rosenvinqea , (3) 

 significantly decreased the abundance of 

 oysters, ascidians, mussels, arborescent 

 bryozoans, small crustaceans, and worms 

 that lived in soft tubes, (4) either 

 increased or did not affect the abundance 

 of barnacles and worms that constructed 

 hard tubes, and (5) initially decreased 

 the establishment of scallops but later 

 indirectly increased scallop survivorship 

 by preying on crabs. These data strongly 

 suggest that temperate fishes can 

 significantly increase the abundance of 

 relatively unpalatable large brown 

 seaweeds and decrease the abundance of 

 competing red and green seaweeds. Thus, 

 previous suggestions that herbivorous 

 fishes are absent from temperate habitats 

 because these habitats are dominated by 



relatively unpalatable browns (Bakus 1969; 

 Montgomery and Gerking 1980) may need to 

 be modified if it is found that herbivory 

 by temperate fishes is an important factor 

 in producing and maintaining the dominance 

 of these browns. 



Because microcosms are not perfect 

 mimics of the natural system, results from 

 field experiments, when they are conducted, 

 could differ from Hay's results if 

 predators or alternate food sources change 

 the foraging behavior of these herbivorous 

 fishes. However, all available data on the 

 natural history, feeding preferences, and 

 feeding behavior of these fishes under 

 laboratory, microcosm, and field conditions 

 suggest that herbivorous and omnivorous 

 fishes of the South Atlantic Bight have a 

 large effect on the organization of 



43 



