crabs and horseshoe crabs. Consequently, the 

 physical impact of skates and rays is ordinarily far 

 greater on unvegetated flats than in nearby grass 

 beds. Because of their relatively large size, most 

 skates and rays prey upon fairly large benthic ani- 

 mals. Their extensive digging activities also cause 

 widespread mortality even among the smallest of 

 benthic organisms. Many smaller predatory 

 species, such as the pinfish, follow the rays and 

 skates in order to consume any smaller inverte- 

 brates which they may uncover but not consume. 

 The excavation pits then undergo colonization by 

 opportunistic species and succession proceeds 

 back toward larger infaunal species (VanBlaricom 

 1978). This characteristic disturbance process 

 makes rays an important determinant of the ben- 

 thic infaunal abundances and community compo- 

 sition anywhere they are common. 



In North Carolina, the most abundant ray, the 

 Atlantic stingray (Dasyatis sabina) does not exca- 

 vate pits, but a locally abundant ray, the cownose 

 ray [Rhinoptera bonasus), does. In spring and fall, 

 large schools of cownose rays often can be tt)und 

 around grass beds in North Carolina's sounds and 

 in the Chesapeake Bay (Orth 1975). Here they 

 damage grass beds somewhat by their digging for 

 food. Cownose rays consume large quantities of 

 commercially valuable shellfish, especially hard 

 clams, scallops, and oysters. Because these rays 

 are so large, their appetites are substantial, and 

 their effects on the benthic ccjmmunities are 

 great. An attempt is now being made by some 

 North Carolina researchers to develop an over- 

 seas market for cownose (and other) rays. In 

 Europe the ray "wings" are cut into scallop- 

 like pieces which are considered a delicacy. De- 

 veloping this fishery in North Carolina would 

 have the added benefit of freeing the hard clam, 

 scallop, and oyster populations from one of their 

 major predators in certain areas. 



The other major category of predators which 

 are most characteristic of intertidal flats is the 

 flatfishes (flounders, soles, and tonguefish). Some 

 flounders employ the tactic of lying buried just 

 beneath the surface of the sediments with only 

 their eyes protruding. While lying on the sediment 

 surface, many flounders (mostly Par alich thy s spp.) 

 are masters of disguise, the chameleons of the ich- 

 thyological world. Here they are able to change 

 not only their coloration to match their back- 

 ground but also the pattern of blotches and marks 



on their skin (Mast 1914), concealing them from 

 their unsuspecting prey. Flounders then dart up 

 out of hiding to capture fish, shrimp, crabs, and 

 other epibenthic species. 



The most important of this flatfish group on 

 the intertidal flats of North Carolina are the 

 summer flounder [Paralichthys dentatus), the 

 southern flounder {P. lethostigma), and the hog- 

 choker [Trmectcs maculatus). The Paralichthys 

 species prey predominantly upon tish, usually 

 silversides, anchovies, and other small fishes, and 

 upon shrimp and crabs. The hogchoker is a small 

 bottom-feeder that captures relatively small prey. 

 Polychaetes and small crustaceans along with detri- 

 tus make up the bulk of its diet. 



The summer flounder and the southern 

 flounder are the most important of these flat- 

 fishes in that they contribute to both the sport 

 and commerical fisheries along the east coast. Ju- 

 venile flounders of both species are year-round 

 residents of shallow waters in North Carolina, 

 living in sounds, lagoons, and estuaries until they 

 are 18 mo old (Powell and Schwartz 1977). They 

 then leave through the inlets for the ocean for 

 spawning. Some adults return to the sounds when 

 the water warms, leaving again for ocean spawning 

 each fall. Floimders weighing up to 8 to 10 lb are 

 not uncommon in North Carolina's sounds. Be- 

 cause of the flounder's habit of lying on shallow 

 flats to await its prey, fishermen often catch 

 flounders by "gigging." This involves walking or 

 poling a boat along in shallow water and using a 

 barbed spear (or gig) to capture any flounder that 

 is encountered. Flounder gigging is most fre- 

 quently practiced at night when flounders are 

 most often found on the shallow flats and when 

 they are relatively inactive. This entire fishing 

 methodology is dependent upon the flounilers' 

 affinity for shallow-water sand flats. 



The hogchoker has been used in experiments 

 to determine its influence on the benthic infaunal 

 community. Virnstein (1977) enclosed hogchokers 

 inside of mesh cages and after varying periods of 

 time took core samples of the benthic infauna. By 

 comparing these cores to cores taken inside cages 

 which lacked all predators, he was able to test 

 whether the hogchoker had a significant impact 

 on the benthic infaunal community. Even though 

 the hogchoker feeds upon benthic infauna, it 

 appeared to have no significant impact on the 



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