FISHERY BULLETIN: VOL. 87, NO. 4, 1989 



{Aspidosiphon spp.) were occasionally consumed 

 by West Indian Calamus. Fishes of the genus 

 Calamus have broad molariform teeth (Gregory 

 1933) that are used to crush the shells of gastro- 

 pods, hermit crabs, and other invertebrates 

 equipped with hard protective shells, and this is 

 reflected in the food of C. leucosteus in the South 

 Atlantic Bight. The motile gastropod shell is ap- 

 parently a visual stimulus to whitebone porgy, 

 which results in ingestion of the shell regardless 

 of its inhabitant. Gastropods, hermit crabs, and 

 sipunculids that were eaten consisted of very 

 small species. All occupied similarly sized shells, 

 and collumbelhd shells (e.g., Costoanachis avara 

 and C. avara shells occupied by other organisms) 

 were the most frequently found shells in stomach 

 samples. 



Whitebone porgy demonstrated a relatively 

 small change in food habits with increasing fish 

 size. This is unusual for sparid fishes, many spe- 

 cies of which switch between a herbivorous habit 

 and an omnivorous or carnivorous habit during 

 different hfe history stages (Christensen 1978; 

 Ogburn 1984; Stoner and Livingston 1984; 

 Darcy 1985a, b; Sedberry 1987). Many of these 

 other sparids occupy grass beds or intertidal 

 waters at certain life history stages and feed on 

 tracheophytes and algae that are common on 

 those shallow-water habitats. Whitebone porgy, 

 like other sparids found in offshore habitats 

 where algae are uncommon, do not feed on plant 

 material (Manooch 1977; Sedberry 1983, 1987). 



Most of the invertebrate species that domi- 

 nated in benthic collections from the hard bottom 

 habitat were not important in the diet of white- 

 bone porgy. Most of these were polychaetes and 

 amphipods that may have been too small to be 

 consumed by a generalized predator like white- 

 bone porgy; however, whitebone porgy probably 

 does not forage directly on hard-bottom reef 

 species, regardless of their size. Dominant prey 

 species such as Aspidosiphon gosnoldi, Glottidia 

 pyramidata, and Onuplns nebulosa are inhabi- 

 tants of sandy bottoms (Wells and Gray 1964; 

 Cutler 1973; Gardiner 1975; Cooper 1977; 

 Fauchald and Jumars 1979), and Leptochela 

 papulata is also commonly found in sandy habi- 

 tats (WilHams 1984). 



Calamus leucosteus had a relatively high 

 overlap in diet with Pagrus pagrus and Archo- 

 sargus probatocephalus. Pagurid decapods and 

 especially the barnacle Balanus trigonns were 

 common in the diet of these three predators but 

 were not consumed by the other sparids ex- 

 amined (South Carolina Wildlife and Marine Re- 



sources Department 1984). Aside from a sessile 

 barnacle species, however, few other sessile or- 

 ganisms were consumed by whitebone porgy or 

 red porgy. Red porgy fed mainly on motile deca- 

 pods and fishes and can be classified as a general- 

 ized predator of motile organisms. Archosargus 

 probatocephalus appeared to depend more on 

 hard bottom habitat for feeding (Sedberry 1987); 

 whereas, Cala)nus leucosteus fed on a combina- 

 tion of motile invertebrates and fishes, in addi- 

 tion to some hard bottom epifaunal species. 



Stenotomus aculeatus had a low overlap in 

 diet with whitebone porgy. Southern porgy, hke 

 whitebone porgy, are frequently taken in trawls 

 over sand bottoms (Wenner et al. 1980), but they 

 are not nearly as abundant as they are in hard 

 bottom habitats (Sedberry and Van Dolah 1984). 

 Southern porgy had a diet dominated by a pe- 

 lecypod (Ervilia concentrica) and a cumacean 

 (Oxyurostylis synithi) that are infaunal sand 

 dweOing species (Van Engel 1972; Porter 1974); 

 by planktonic species (copepods, Calanopia 

 americana, and the caprellid Phtisica marina); 

 and by an epifaunal amphipod (Erichthonius 

 brasiliensis) that were rarely consumed by 

 whitebone porgy (South Carohna Wildlife and 

 Marine Resources Department 1984; this study). 

 Since these two sparids feed heavily on sand 

 dwelling benthos or near-bottom plankton, they 

 are apparently not dependent on hard bottom 

 habitat for food, although they are found in 

 higher densities in hard bottom areas. Because 

 they feed on different kinds of organisms (in- 

 faunal sedentary or planktonic species for south- 

 ern porgy versus motile epifaunal species for 

 whitebone porgy), there is little overlap in diet 

 between these two species. 



Overlap in diet between pinfish and whitebone 

 porgy was very low. Pinfish examined in the 

 present study ate primarily a hard-bottom, ses- 

 sile, tube-dwelling amphipod, Erichthonius 

 brasilieMsis, (36% of prey items) that was rarely 

 consumed by whitebone porgy. Pinfish are ap- 

 parently more closely associated with substrates 

 from which they can browse on attached organ- 

 isms, as has been noted in previous studies 

 (Stoner and Livingston 1984). Because pinfish 

 fed on attached epifauna, this species was similar 

 in diet to sheepshead, a heavy grazer on at- 

 tached epifauna (Sedberry 1987). Whereas 

 Calamus spp. possess conical teeth in the ante- 

 rior of the jaws for gi-asping motile prey and 

 strong molariform teeth on the sides for crushing 

 shells (Gregory 1933; Randall and Caldwell 1966; 

 Randall 1967), the anterior of the jaws of pinfish 



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