;39 



of the atria and ventricle. Venus mercenaria apparently has no nerve cells 

 in the heart. Hearts of Venus and many other lamellibranchs are used as 

 test objects in bioassays for ACh. For the heart of V. mercenaria it is 

 reasonably well established that ACh is the transmitter substance of the 

 cardio-inhibitory fibers. During nervous inhibition a substance is released . 

 which has the same effect on heart as ACh. Eserine prolongs the inhibition 

 produced by stimulation of the inhibitory nerve supply, and Mytolon (benzo- 

 quinonium chloride) , which prevents ACh action, blocks action of inhibitory 

 nerves. Welsh (19 57) believed that 5-hydroxytryptamine (5HT) was the accel- 

 erating transmitter in Venus, but there is little evidence for this except 

 that this compound occurs in ganglia of hard clam and heart is rather sensi- 

 tive to 5HT. Anodal current has been reported to produce decreased heart 

 rate and relaxation in Venus, where ACh is inhibitory, but others have 

 stated that the same inhibition by anodal current occurs in heart of Mytilus, 

 where ACh excites. Intriguing problems are posed by existing rather frag- 

 mentary observations on mollusks. They merit greater attention. - J.L.M. 



Florkin, Marcel. 1966. 



Nitrogen metabolism. In Physiology of Mollusca. Karl M. Wilbur and C. M. 

 Yonge (edsj . Academic Press, New York, Vol. II: 309-351. 



Contains references to Mercenaria (Venus) mercenaria abstracted elsewhere 

 in this bibliography. Also omits some important references. - J.L.M. 



590 



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



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



Mercenaria mercenaria is mentioned numerous times, but spasmodically, to 

 illustrate where necessary. The references are all abstracted elsewhere in 

 this bibliography. - J.L.M. 



591 



Flower, H. Butler. 1979. 



Shellfish mariculture in New York State. Proc. Symp. Mariculture in N.Y. 

 State, N.Y. Sea Grant Inst, and Cornell Univ. NYSGI-RP-79-01 : 19-22. 



Describes briefly mariculture operations carried out by Shellfish Inc. and 

 Bluepoints Co. of West Sayville, the Shinnecock Indian project, Long Island 

 Oyster Farms at Northport , the Shelter Island Oyster Co. at Greenport, and 

 Frank M. Flower and Sons Inc. at Bayville. Commercial shellfish hatcheries 

 are relatively new, and are still in the process of demonstrating that they 

 are economically viable. - J.L.M. 



592 



Foehrenbach, Jack. 1972. 



Chlorinated pesticides in estuarine organisms. J. Water Poll. Contr. 44(4): 

 619-624. 



Mercenaria mercenaria from 10 locations along the north and south shores and 

 eastern end of Long Island, N.Y. were analyzed for residues of DDT, DDE, DDD, 

 dieldrin, endrin, aldrin, heptachlor, lindane, and heptachlorepoxide, from 

 October 1968 to July 1970. At least 12 animals were used for each analysis. 

 Of the chlorinated hydrocarbons, only DDT, DDD, DDE, and dieldrin were found. 

 Residues of DDT+DDD+DDE ranged from 0.000 to 0.115 mg/kg wet weight organic 

 tissue. Dieldrin ranged from 0.000 to 0.093 mg/kg. All values were well 

 below limits set for shellfishes by Food and Drug Administration. Animals 

 at higher trophic levels, such as birds, had much greater residues. Thus, 

 animals feeding on hard clam could be affected adversely. Little is known 

 about long-term effects of low-residue concentrations. Thus all synthetic 

 chemicals should be used with caution. - J.L.M. 



165 



