1358 



Motley, H. L. 1934. 



Physiological studies concerning the regulation of heart beat in fresh water 

 mussels. Physiol. Zool. 7: 62-84. 



Listed in Brown (1950) in bibliography for Venus meraenaria with reference to 

 chapter by Pierce, abstracted elsewhere in this bibliography. - J.L.M. 



1359 



Moulton, James M. 19 53. 



Gustafson's growth experiment on Venus in Casco Bav. 4th Conf. on Clam 

 Research 1 p. (mimeo) . 



A study was started in June 1952 by planting quahogs of various sizes in 

 localities between West Bath and Freeport, Maine. Preliminary data showed 

 that quahogs in one area grew 3 times as fast as in another, and that growth 

 leveled off in Sept in both places. (Abstracter's note: This is not an 

 adequate citation. This is believed to be the series of conferences sponsored 

 informally by Bureau of Commercial Fisheries, never formally published as 

 such.) - J.L.M. 



1360 



Moulton, James M., and Gareth W. Coffin. 1954. 



The distribution of Venus larvae in Orr's Cove plankton over the tide cycle 

 and during the summer and early fall of 1953. Me. Dept. Sea Shore Fish., 

 Research Bull. 17, 51 p. 



In individual tidal cycles there was apparently little consistency between 

 tide stage and peak of Venus larval distribution. Summation of all 

 observations, however, appeared to show that on the average, greatest 

 numbers of larvae were present in the period 3 hrs after high tide to 1 hr 

 before low tide, and smallest numbers from 1 hr before to 1 hr after low 

 tide. Larvae were present at least fron beginning of July to nearly end of 

 Sept, with peaks early in July and at end of Aug. Dense sets of Venus which 

 have occurred in Orr's Cove appear to have been the result of postlarval 

 redistribution rather than of concentrated setting. It is emphasized that 

 results of one summer's work cannot be considered conclusive. Weather 

 fluctuations and other variables can affect results substantially. Detailed 

 tables of observations are included. - J.L.M. 



1361 



Moulton, J. M., and A. H. Gustafson. 1956. 



Green crabs and the redistribution of quahogs. Science 123(3205): 992. 



Green crab, Caroinides maenas , is an important predator of quahog, Venus 

 meroenaria, as well as a minor factor in redistributing quahog populations. 

 A green crab was observed moving about with a one-inch quahog pinched onto 

 the tip of one of its walking legs. When disturbed, the quahog amputated 

 the tip of the crabs leg, which nicked the edge of each valve of the quahog 

 shell. Of 26 quahogs found resting on top of the substrate at Sebascodegan 

 Island, Maine, 24 had shell margins marked as described above. It is assumed 

 that these quahogs were redistributed by attaching themselves to a crab's leg 

 when a crab inadvertently placed a leg tip between open valves of a quahog. 

 Of 1000 quahogs between 1.5 to 5.0 cm sampled, 2.9 percent had circular 

 nicks at shell margins. Green crab may therefore benefit quahogs to a small 

 degree by thinning crowded populations. There may also be correlation 

 between quahog density and frequency of missing leg tips of crabs, or quahog 

 shell nicks and green crab abundance. - W.J.B. 



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