2009 



Wieser, Wolfgang. 1960. 



Benthic studies in Buzzards Bay. II. The meiofauna. Limnol . Oceanogr. 5(2): 

 121-137. 



Mercenaria (Venus) mercenaria is not mentioned. - M.W.S. 



2010 



Wijsman, Theodorus C. M. 1977. 



Reliability of the enzymatic determination of adenosine phosphates in crude 

 extracts of marine bivalves. Comp. Biochem. Physiol. 58B(3): 313. 



Mercenaria mercenaria is not mentioned. - J.L.M. 



2011 



Wilber, Charles G. 1947. 



Urea and uric acid in molluscs. Anat. Rec . 99(4): 111. 



Urea in Venus mercenaria was surprisingly high, 92 mg/100 cm . - J.L.M. 



2012 



Wilber, Charles G., and E. S. McDonald. 1947. 



Iron and ironic compounds in molluscs. Anat. Rec. 99(4): 112. 



Venus mercenaria is included. - J.L.M. 



2013 



Wilbur, Karl M. 1960. 



Shell structure and mineralization in molluscs. In Calcification in 

 Biological Systems. Reidar F. Sognnaes (ed.) , AAAS Pub. 64, Washington, 

 D.C.: 15-37. 



Mercenaria (Venus) mercenaria is not mentioned. - J.L.M. 



2014 



Wilbur, Karl M. 1964. 



Shell formation and regeneration. Chapter 8 in Physiology of Mollusca. 

 Vol. 1. Karl M. Wilbur and C. M. Yonge (eds.) . Academic Press, New York: 

 243-282. 



Shell formation in mollusks essentially consists of deposition of crystals 

 of calcium carbonate on an organic matrix which is largely protein 

 (conchiolin) . Shell is laid down by mantle. Rate of increase in shell area 

 is a function of increase in mantle area, whereas rate of increase in 

 thickness and weight of shell is a function of rate of secretion of CaCC>3 

 and organic matrix. Shell is formed within a thin layer of fluid 

 (extrapallial fluid) enclosed between mantle and inner shell surface. Two 

 solid phases form from this fluid, organic matrix and crystalline components. 

 In Crassostrea and others extrapallial fluid has access to the external 

 medium, but in M. mercenaria not. Not much is known about composition of 

 this fluid. In M. mercenaria exposure of extrapallial fluid to air for 2 

 min resulted in a decrease of a few tenths of a pH unit in summer or a slight 

 increase in winter, presumably from uptake or loss of C02. In hard clam pH 

 of extrapallial fluid was 7.37 + 0.02, of blood 7.52 + 0.11 (confidence 

 limits at 95% level). Summer values were approx. 0.4 pH unit higher than 

 winter. Species with aragonite shell, like M. mercenaria, have 3 or more 

 protein fractions in extrapallial fluid, as in blood, although migration 

 velocities are not always the same for the 2 fluids. The mechanism by which 

 mantle cells are caused to secrete periodically has not been examined 

 experimentally. Apparently stimuli are received by the shell side of the 

 mantle. A potential of 0.5-2.0 mv is present across the isolated mantle of 

 M. mercenaria, the shell side is positive. X-ray diffraction shows that the 



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