FISHERY BULLETIN: VOL. 84, NO. 3 



(lat. 31°26'N, long. 80°20'W; central South Atlan- 

 tic Bight). Angling gear was standard hand-operated 

 boat rods rigged with double-hooked terminal 

 tackle and baited with squid. Hook sizes were 3/0 

 to 5/0. Fishes were brought to the surface as quick- 

 ly as possible (about 1 m/s; somewhat slower for 

 large snappers and groupers). Trawling was con- 

 ducted from two vessels, each rigged for stern 

 trawling but with some differences in gear and 

 handling. 



The trawl gear on the RV Georgia Bulldog was 

 a 25 m, 4-seam high-rise roller trawl with tongue. 

 Meshes were (stretched) 20 cm in the wings and 

 tongue, 10 cm in the belly and bag (2 cm liner), and 

 7.5 cm in an extension. Cables connecting the trawl 

 and doors produced a sweep of 31.1 m; the rise on 

 the tongue was 6.1 m (J. B. Rivers 4 ). The rig had 

 a vertical haulback rate of 0.12-0.15 m/s. 



The trawl gear on the RV Blue Fin was a modified 

 No. 36 Yankee flat roller trawl. Meshes were 

 (stretched) 5 cm in the wings and belly and 3.5 cm 

 in the bag (2 cm liner). The total sweep was 22.1 

 m and the rise at the center of the headrope was 

 3.7 m (Rivers fn. 4). The rig had a vertical haulback 

 rate of 0.1 m/s. Gear handling was otherwise 

 identical. 



Tows were 20 min long. The fish catch was sorted 

 to species and the alimentary tracts samples re- 

 moved; or samples were placed in 20 L buckets with 

 ice-seawater mixture, frozen on board, and pro- 

 cessed in the laboratory. Data on anatomical trauma 

 were recorded during dissections. An angling catch 

 of 34 black sea bass, Centropristis striata, was put 

 on ice and dissected 2 days later for examination 

 of internal trauma. No samples were subjected to 

 the bin-type icing procedures common on commer- 

 cial snapper-grouper vessels. Fishes were collected 

 from July through December in 1983 and in Sep- 

 tember 1984. 



External evidence of trauma consisted of several 

 types of protrusion of the gastrointestinal tract. 

 These were classified as 



1) Oral eversion - stomach everted into the 

 pharynx and often present in the mouth, pull- 

 ing the pyloric area and the intestine with it. 



2) Cloacal protrusion - intestine protruded from 

 the cloacal area. Initially such protrusions were 

 not classified further; however, detailed dissec- 

 tions showed that they were either 



4 J. B. Rivers, Marine Fisheries Specialist, University of Georgia 

 Fisheries Extension Station, POB Z, Brunswick, GA 31523, pers. 

 commun. October 1984. 



a) Herniations - disruptions of the body wall 

 in the pericloacal area through which the 

 gut protruded or 



b) Intussusceptions - actual eversion of the 

 terminal portion of the intestine through its 

 own lumen. 



3) Branchial protrusions - portions of the gut pro- 

 truded through the branchial opening. 



Results are expressed as occurrences and percent- 

 age frequencies. Frequencies of herniations and in- 

 tussusceptions were calculated by dividing the 

 observed number in a class by the total number of 

 classified cloacal protrusions, then multiplying the 

 result by the total proportion of cloacal protrusions. 

 Example (from Table 1): planehead filefish herni- 

 ations, (99/(99 + 22)) (160/440) = 0.30. 



Internal evidence of trauma included 1) the pres- 

 ence of gas in the tissues (tissue emphysema) and 

 2) rupture of the swim bladder. Although notes on 

 both phenomena were kept for all fish species, their 

 frequencies were enumerated only for the 34 care- 

 fully examined, angling-caught black sea bass. 



Among-species and between-gear comparisons of 

 trauma were performed by using Pearson's test for 

 goodness of fit (yielding a x 2 value). The null 

 hypotheses were specified as homogenous (equal) 

 proportions of specimens exhibiting a particular 

 symptom, based on the overall proportion of fish 

 with the symptom across species or gears (signifi- 

 cant departures were P < 0.05). 



RESULTS 



Dissection records of 1928 trawl-caught and 235 

 angling-caught fishes of 15 species were collated for 

 external evidence of trauma (Table 1). Seven species 

 were not caught with angling gear. Scamp, Myctero- 

 perca phenax, and gag, M. microlepis, were com- 

 bined to form a Mycteroperca grouper category due 

 to low numbers collected. 



Trawl-caught red snappers, Lutjanus campecha- 

 nus; Mycteroperca groupers; short bigeyes, Pristi- 

 genys alta; planehead filefish, Monacathus hispidus; 

 orange filefish, Aleuterus schoepfi; and blue angel- 

 fish, Holacanthus bermudensis, experienced fre- 

 quent gut displacements (Table 1). These were oral 

 eversions in red snappers, short bigeyes, and Myc- 

 teroperca groupers; cloacal protrusions in orange 

 filefish and blue angelfish; and all three categories 

 (including branchial protrusion) in planehead filefish. 

 Alimentary tract displacements were minimal in 

 trawl-caught black sea bass; bank sea bass, Centro- 

 pristis ocyurus; sand perch, Diplectrumformosum; 



698 



