BIOLOGY AND NATURAL HISTORY 151 



Glaser (1904) showed that young "coon" oysters, when separated and given 

 ample space, quickly recover from the elongated shape and grow into well- 

 shaped oysters. The shape and condition of the oysters appear then to be due 

 to environmental effects. 



The presence of these oysters in waters of high salinity in North Carolina 

 seems to indicate that some correlation exists between high salinity and the 

 shape or condition of the oysters. Coon oysters are generally considered as 

 worthless and inferior, and are used for the lowest grades in canning. They 

 are, however, indirectly valuable to the industry in providing a source of 

 spawn to replenish the seed supply in the immediate area. 



ENEMIES. North Carolina is fortunate in that the enemies of the oyster are 

 not as numerous as in many other oyster producing areas. Pamlico Sound is 

 virtually free of predatory forms except crabs and some species of fish. The 

 destruction by oyster drills, starfish, and conchs in Core, Bogue, and other 

 sounds is perhaps small in comparison with that in other states. The boring 

 sponge, Cliona, is known to cause damage to oysters in the North and New 

 rivers area. Old (1941) reports five species of Cliona in the Beaufort area. 

 The mud worm, Polydora, is prevalent in oysters from widely distributed 

 areas in North Carolina. Heavy infestations are found in oysters from Bogue 

 Sound and at Ocracoke Inlet. The various species of this worm have been 

 described by Hartman (1945) for North Carolina. In the Beaufort area, 

 Prytherch (1940) has reported oysters heavily infected with the sporozoan 

 parasite Nematopsis ostrearum. The extent of damage by this parasite has 

 not been reported. The occurrence of the parasite Bucephalus, the cercaria 

 (larval form) of a trematode parasite G aster ostomum, has been found in 

 oysters from Pamlico Sound and Newport River (Grave, 1904; Tennent, 

 1909). This parasite prevents the formation of reproductive elements and 

 renders the host incapable of withstanding adverse conditions. 



SANITARY REGULATIONS 



From the standpoint of sanitary regulations the oysters sold for public 

 consumption are among the purest food products on the market. Following 

 the epidemic of typhoid in some midwestern cities which was presumably 

 caused by eating oysters, strict rules and regulations were formulated by the 

 Federal Public Health Service and the various state Boards of Health. North 

 Carolina adopted the set of rules and regulations formulated by the United 

 States Public Health Service in 1925. Within the past decade some remark- 

 able advances have been made in the State toward the building and main- 

 tenance of sanitary shucking houses. The North Carolina State Board of 

 Health surveys the waters of shellfish growing areas for indices of pollution 

 and periodically examines the packing houses. According to Mr. N. McK. 



