Able et aL: Transitions in morphological features, habitat use, and diet of Lophius omencanus 



467 



approximately the Virginia-North Carolina state line 

 north to eastern Long Island, NY, where they were 

 found in shallow nearshore waters. The benthic YOY 

 goosefish also were present up the Hudson Canyon 

 shelf valley. Few benthic YOY goosefish were collected 

 in waters off Rhode Island and southern Massachu- 

 setts — likely the result of lower sampling effort (Fig. 

 5). On Georges Bank, the benthic YOY goosefish were 

 distributed around the perimeter of the bank but were 

 not collected as frequently on the eastern end of the 

 bank, even though these areas were well sampled. YOY 

 goosefish were occasionally collected off the "elbow" of 

 Cape Cod, but were found infrequently in the Gulf of 

 Maine. 



Benthic juveniles are probably more widely distrib- 

 uted over the continental shelf and on the upper slope 

 than indicated by the sea scallop survey. The best evi- 

 dence for their distribution in deeper waters has been 

 from four seasonal cruises centered on the continental 

 shelf and slope off Virginia covering depths to 3080 m 

 (Wenner, 1978; Wenner^). Many juveniles were collected 

 at depths from 75-900 m and the greatest density was 

 found at 200-399 m depths. A large number of these 

 individuals (30%) were <120 mm TL and the smallest 

 specimen was 53.4 mm TL. 



Food habits and habitats 



The stomach contents of YOY goosefish in the Middle 

 Atlantic Bight were diverse (Table 4). The dominant prey 

 group in the stomach contents comprised fish (45. 1% fre- 

 quency of occurrence [FO]) and crustaceans (17.6% FO). 

 The most numerous prey fish were gadids, Ammodytes, 

 and bothid and pleuronectid flatfishes. Invertebrates 

 were also consumed, including mollusks, chaetognaths, 

 nematodes, nemerteans, trematodes, polychaetes, and 

 crustaceans. This diversity of prey has been frequently 

 reported for juveniles and adults of L. americanus (Sed- 

 berry, 1983; Armstrong et al., 1996; Bowman et al., 

 2000; Caruso, 2002) and other congeners, including L. 

 piscatorius (Tsimenidis, 1980; Crozier, 1985, Laurenson 

 and Priede, 2005) and L. budegassa (Tsimenidis, 1980). 

 The greater occurrence of invertebrates in the stomachs 

 of L. americanus in our study (67.2% FO, Table 4) than 

 in prior studies (Sedberry, 1983; Armstrong et al., 1996) 

 was probably due to our emphasis on examining smaller 

 YOY fish. 



The food habits of YOY goosefish varied with fish size; 

 a shift to a larger proportion of fish in the diet occurred 

 at larger sizes (Fig. 6, A and B). Although inverte- 

 brates were common in the diet of all YOY examined, 

 they occurred in 100% of the stomach contents at sizes 

 smaller than approximately 50 mm TL and to a vari- 

 able extent in most larger YOY fish. The vast majority 

 of stomach contents, on the basis of weight (Table 4), 

 were composed of fish in larger goosefish. Prior studies 



3 Wenner, C. 2004. Personal commun. Marine Resources 

 Research Institute South Carolina Department of Natural 

 Resources, P.O. Box 12559, Charleston, SC 29422. 



are equivocal on ontogenetic change in diet. Armstrong 

 et al. (1996) reported smaller (<200 mm TL) individu- 

 als to have a higher proportion of invertebrates in their 

 diet than we observed. Sedberry (1983) found the diets 

 of all size classes of goosefish, including the two small- 

 est (<100 and 101-200 mm), were dominated by fishes. 

 Our results clarify the sizes at which this change to 

 piscivory occurs (i.e., >50 mm TL). 



The food habits also changed as a result of the tran- 

 sition from presettlement (pelagic) to postsettlement 

 (benthic) habitats (Fig. 6, C and D). Individuals that 

 were captured in the water column (<50 mm TL) had 

 pelagic taxa such as chaetognaths, hyperiid amphipods, 

 calanoid copepods, and ostracods in their stomachs. The 

 dominance of pelagic prey was apparent whether prey 

 were quantified as percent weight or percent frequency 

 of occurrence. The stomach contents of larger individu- 

 als (60-280 mm TL, YOY, and small juveniles) were 

 dominated by benthic prey when expressed as percent 

 frequency of occurrence. The shift to benthic prey was 

 not as obvious, however, when prey were expressed as 

 percent weight. This was due to a large percentage of 

 prey items that could not be assigned unequivocally 

 to either benthic or pelagic habitats. The benthic prey 

 comprised a variety of fishes and crustaceans including 

 amphipods, cumaceans, mysids, shrimps, nematodes, 

 nemerteans, and polychaetes (Table 4). The location of 

 capture of some prey, such as that of small gadids and 

 squid, was considered indeterminate because these prey 

 could have been consumed by goosefish in either pelagic 

 or benthic habitats. 



