In 1978 there were 22,728 licensed shellf ishermen in New Jersey, of which 

 9 5% were recreational, 4% were part time, and 1% were full time commercial. 

 Two-thirds of the 58 million clams harvested that year were taken commer- 

 cially. Sixty percent of the catch was taken from the eelgrass beds of 

 Little Egg Harbor. Full time commercial men averaged 622 clams per day, 

 part time 416 and recreationalists 164. Methods of fishing are discussed. 

 Hard clams are found in bays where salinity is above 15 c / 00 . A license is 

 required. Clams smaller than 1 1/2 inches in length must be returned to 

 the water. Clamming is not allowed in polluted water or leased beds. These 

 areas are marked on available charts, and leased beds are marked with cedar 

 stakes. - J.L.M. 



2122 



Florkin, Marcel, and S. Bricteux-Gregoire. 1972. 



Nitrogen metabolism in mollusks. In Chemical Zoology. VII. Mollusca. 

 Marcel Florkin and Bradley T. Scheer (eds.) , Academic Press, New York: 

 301-348. 



Tropomyosin has been isolated from Venus rnevcenaria (Riddiford and Scheragra 

 1962) . 5-Hydroxytryptamine has been found in nerve and heart tissue of 

 Venus rnercenavia (Welsh and Moorhead 1959). 5-Hydroxytryptophan was found 

 in presence of nerve extracts of Mercenaria rnercenavia (Welsh and Moorhead 

 1959). Carnitine (8-Oxy-y-butyrobetaine) has been found in Venus rnercenavia 

 by Fraenkel (1954) . - J.L.M. 



2123 



Florkin, Marcel, and Bradley T. Scheer . (eds.) . 1972. 



Chemical Zoology. VII. Mollusca. Academic Press, New York, xxi + 567 p. 



A very complete survey of the mollusks, arranged according to the following 

 chapter headings: The Molluscan Framework, Structure of the Molluscan Shell, 

 Shell Formation in Molluscs, Byssus Fiber-Mollusca, Chemical Embryology of 

 Mollusca, Pigments of Mollusca, Respiratory Proteins in Mollusks, Carbohy- 

 drates and Carbohydrate Metabolism in Mollusca, Lipid and Sterol Components 

 and Metabolism in Mollusca, Nitrogen Metabolism in Mollusks, Endocrinology 

 of Mollusca, Ionoregulation and Osmoregulation in Mollusca, Aspects of 

 Molluscan Pharmacology, Biochemical Ecology of Mollusca. Chapters that 

 specifically mention Mercenaria mercenaria are abstracted under authors' 

 names, but the whole thing is worth reading for a complete discussion of 

 the subject up to about 1971. - J.L.M. 



2124 



Fowler, Bruce A., Douglas A. Wolfe, and William F. Hettler. 1975. 



Mercury and iron uptake by cytosomes in mantle epithelial cells of quahog 

 clams (Mercenaria rnercenavia) exposed to mercury. J. Fish. Res. Bd. Canada 

 32(10) : 1767-1775. 



The ultrastructural appearance of mantle epithelial cells from clams exposed 

 to 0.1 ppm Hg concentration was indistinguishable from that of controls. 

 Epithelial cells of clams exposed to 1 ppm mercury concentration contained 

 increased numbers of dense cytosomes. These were most prevalent in the 

 apical aspect of cells immediately beneath the microvilli of the brush bor- 

 der. Greater numbers of dense cytosomes were seen in mantle epithelial 

 cells of clams exposed to 10 ppm Hg concentration. Examination of cytosomes 

 in adjacent sections by energy dispersive X-ray microanalysis showed high 

 iron concentrations in relation to Hg within these bodies. Using the thin 

 section quantified model developed by Russ (1974), the Fe:Hg mass ratio 

 within the cytosomes was calculated to be 4.73:1. The results indicate that 

 cytosomal uptake is one mechanism by which molluscan cells may take up metals 

 from their environment. Metal sequestration by cytosomes probably represents 

 a mechanism by which shellfish can concentrate Hg rapidly from their envi- 

 ronment without being killed. Alteration of essential trace metal levels 

 in shellfish following chronic Hg exposure has not been reported previously. 

 The mechanisms by which Hg could alter mantle fringe iron levels without 

 discernible morphological damage are unknown and await further study. - J.L.M. 



591 



