182 MARINE FISHERIES OF NORTH CAROLINA 



provide an additional source of income to the residents and revenue to the 

 State. 



MISCELLANEOUS MOLLUSKS 



A great variety of mollusks are found in North Carolina, perhaps because 

 Cape Hatteras forms a natural boundary between the southern and northern 

 forms. Many of the mollusks are of little interest commercially but their 

 presence may indicate a dormant potentiality, since a number of species in 

 North Carolina waters are harvested in commercial quantities farther north 

 or south. A few species of commercial importance are mentioned briefly. 



RIBBED MUSSELS 



The ribbed mussels, also known as horse mussels {Modiolus plicatulus, 

 sometimes listed as M. demissus) grow in the intertidal zone, imbedded in 

 the bottom between the roots of marsh grass held together by a byssus in 

 clumps or "tumps." The little meat content, characterized by a yellow- 

 orange color, is generally regarded as not edible, although many local people 

 along the coast steam the mussels or make fritters and report them to be 

 "rich" with an excellent flavor. Prior to and during the war years chemical 

 concerns extracted from the meats a provitamin D which was converted 

 to vitamin D by ultra-violet irradiation. Apparently the demand decreased 

 when spinal cords from meat packing plants were found to be a more satis- 

 factory source. In the Beaufort area, a cannery steamed these mussels for 

 the market that existed, but the industry was short-lived perhaps because 

 of an exhausted supply. The mussels are gathered in considerable quantity 

 on the eastern shore of Maryland and in Virginia, New Jersey, and South 

 Carolina. The range of the ribbed mussel is from Nova Scotia to Georgia. 



SEA MUSSELS 



Sea mussels (Mytilus edulis), known as blue or black mussels, have be- 

 come of significant importance in the New England area, where they are 

 steamed and canned. The potentialities of this industry are great in the 

 northern states where this mussel is abundant. Sea mussels are circumpolar 

 in distribution, and are considered a cold water form; however, the south- 

 ernmost limit is South Carolina and it may be that beds of these mussels 

 grow off the coast. They have been popular in Europe for many years, and 

 some progress has been made toward making them more popular in this 

 country. For an account of the sea mussel in all its most important aspects, 

 the extensive paper of Field (1922) should be consulted. 



The state of Maine was the leading producer of sea mussels in 1945. 

 The catch by states in 1945, according to Federal statistics was as follows: 



