hemoglobin than adductor muscles. Heart and adductor muscle soluble 

 proteins in starch gel electrophoresis show zones in identical position, 

 as do digestive gland (hepatopancreas) , serum, nerve, or crystalline style. 

 At least 30 soluble proteins have identical electrophoretic mobilities in 

 the two "species". Aside from the external morphology of the shell, the 

 only readily discernible difference between northern and southern quahog is 

 the tissue localization of myoglobin. The question then arises whether 

 differences in myoglobin levels between hearts and adductor muscles of the 

 two species is a response to unknown differences in internal respiratory 

 physiology, persisting even when animals are raised for years under identical 

 conditions, or do different "control" genes exist? - J.L.M. 



1235 



Manwell, Clyde. 1964. 



Chemistry, genetics, and function of invertebrate respiratory pigments - 

 Configurational changes and allosteric effects. In Oxygen in the Animal 

 Organism. Frank Dickens and Eric Neil (eds.) . I.U.B. Symposium Series 31, 

 MacMillan Co. (Pergamon) , New York: 49-119. 



The only reference to Mercenaria mercenaria in this chapter is to unpublished 

 work by the author which showed that the variable heart hemoglobin of hard 

 clams appeared to be biochemically and genetically different from its 

 adductor muscle hemoglobin. - J.L.M. 



1236 



Manzi, John J., and Kathleen A. Donnelly. 1971. 



Staining large populations of bivalve larvae. Trans. Am. Fish. Soc. 100(3): 

 588-590. 



Eleven stains and dyes, in 5 concentrations, were tested on American oyster 

 and Mercenaria meroenavia larvae. Five did not color the animals, one was 

 toxic at all concentrations. Neutral red gave the best results. No 

 substantial differences were noted between the two bivalves, except that 

 hard clam larvae appeared to be less affected by toxic stains and dyes and 

 had lower mortality and abnormality. Best staining was obtained with long 

 exposure (24 to 48 hrs) to very low dye concentrations (2.5 to 5 ppm) . - J.L.M. 



1237 



Manzi, John J., Victor G. Burrell, Jr., and W. Z. Carson. 1980. 



A mariculture demonstration project for an alternative hard clam fishery 

 in South Carolina: Preliminary results. 11th Ann. Meeting, World Marie. 

 Soc, New Orleans, La., March 1980, 9 typed pages, 1 table, 6 figs. 



Growth of seed Mercenaria mercenaria averaged 2 mm/month over a 13 month 

 period (Oct 78 to Nov 79) . Aggregate cover provides sufficient protection 

 against predation during early grow-out. Combination of crushed gravel 

 substrate and covers on trays provided sufficient protection for seed clams 

 throughout the experiment. Survival of young seed clams (about 4 mm) in 

 densitites as high as 5000/rn-^ was exceptionally high for a 3-month trial 

 period. Preliminary results show that high density cage clam culture is 

 feasible for initial seed clam growth, and may be feasible for commercial 

 production of large seed and market size clams. - J.L.M. 



1238 



Marak, Robert R. 1953. 



Variations in sizes and rate of growth of lamellibranch larvae of the same 

 parents. Natl. Shellf. Assn., Convention addresses 1951: 45 (abstract). 



Larvae from eggs of a single female Venus mercenaria fertilized with sperm 

 of a single male were grown to metamorphosis. Larvae from the same parents, 

 kept under identical conditions, varied widely in growth rate, size, and 

 time to setting. - modified author's abstract. - J.L.M. 



346 



