171 



Boadle-Biber, Margaret C ., and Robert H. Roth. 1972. 



Factors modifying the synthesis of dopamine from tyrosine in pedal ganglia 

 of Mercenaria mercenaria (Mollusca) . Comp. Gen. Pharmacol. 3(9): 61-74. 



The catecholamine, dopamine (DA) , is present in the 3 ganglia of hard clam, 

 but pedal ganglion is by far the richest source (236+16 ng) , which is about 

 200 ug/g wet weight. Visceral and cerebral ganglia contained 76±3 and 37±5 

 ng DA, respectively . The 5-hydroxytryptamine (5HT) content of the 3 ganglia 

 was 101, 116, and 107 ng, respectively . Endogenous noradrenaline (NA) was 

 not found. Enzymatic capacity for making DA from tyrosine was present in 

 pedal ganglia of M. mercenaria , but 3 ,4-dihydroxyphenylalanine (dopa) was 

 not found. 5HT was also formed from tryptophan in pedal ganglia. Incubation 

 of pedal ganglia in KCl-rich seawater accelerated synthesis of DA from 

 tyrosine 2- to 3-fold compared to controls. Specific activity of DA isolated 

 from K -stimulated ganglia also was increased. Acceleration of DA synthesis 

 appeared to take place at the tyrosine hydroxylation step. Synthesis of DA 

 from tyrosine in pedal ganglia was inhibited up to 60% by 10 - ^ M DA in the 

 medium. - modified authors' abstract - J.L.M. 



172 



Bockrath, Joseph, and Diana Wheeler. 1975. 



Closed-cycle mariculture in Maryland, Virginia, and Delaware: An examination 

 of the adaptability of existing fishery laws to new technology. William and 

 Mary Law Rev. 17(1): 85-107. 



Delaware has fortuitously drafted fishery laws that will readily accommodate 

 closed-cycle mollusk mariculture. The fate of artificial shellfish cultiva- 

 tion, however, may depend upon the almost unlimited discretion of the Sec- 

 retary of the Department of Natural Resources and Environmental Control to 

 regulate the shellfish industry. In Maryland and Virginia the head of the 

 comparable agency does not hold such power, and the degree to which closed- 

 cycle mariculture fits into the framework of shellfishery laws is directly 

 dependent on the wording and the intent of the statutes. Application of the 

 statutes of these two states is sufficiently uncertain to discourage the 

 development of a new industry. If Maryland and Virginia wish to encourage 

 closed-cycle mariculture development, adoption of entirely new statutes will 

 be necessary. - J.L.M. 



173 



Boehm, Paul D., and James G. Quinn. 1976. 



The effect of dissolved organic matter in sea water on the uptake of mixed 

 individual hydrocarbons and number 2 fuel oil by a marine filter-feeding 

 bivalve (Mercenaria mercenaria) . Estuarine Coastal Mar. Sci. 4: 93-105. 



Hard clams were exposed in the laboratory to an n-alkane, hexadecane, an 

 aromatic hydrocarbon, phenanthrene, and no. 2 fuel oil in seawater. In one 

 series of exposures naturally occurring surfactant dissolved organic matter 

 (DOM) was removed from natural seawater with activated charcoal, in another 

 it was not. Removal of DOM from the media gave a statistically significant 

 increase in uptake of hexadecane, no change in uptake of phenanthrene, and a 

 sevenfold increase in quantity of no. 2 fuel oil taken up. When DOM is 

 present it takes up saturated hydrocarbons and they are thus taken up less 

 readily by clams. When DOM is removed these hydrocarbons are retained more 

 readily by clam gills because their physical state in seawater is changed. 

 - modified authors' abstract - J.L.M. 



174 



Boehm, P. D., and J. G. Quinn. 1977. 



The persistence of chronically accumulated hydrocarbons in the hard shell 

 clam Mercenaria mercenaria . Mar. Biol. 44(3) : 227-233. 



Hard clams from the chronically polluted environment of the Providence River, 

 R.I. were held in a flowing seawater system in the laboratory for 120 days 

 for depuration. Initial temp was 20.5°C, maximum 22.5°C, and final temp 

 after 120 days 11.5°C. Hydrocarbon content of meats at beginning of the 



49 



