609 



Freeman, John A., and Karl M. Wilbur. 1948. 



Carbonic anhydrase in molluscs. Biol. Bull. 94(1): 55-59. 



Carbonic anhydrase was found in nearly all of 12 pelecypod species and 8 

 gastropod species examined. It catalyses hydration of CO2 and it is 

 suggested that the enzyme plays a role in deposition of carbonate in shell. 

 In Venus mercenaria ratios of no extract to extract of 2.6, 4.8, and 2.5 were 

 observed in mantle edge; 3.3, 2 . 6, and 4.1 in mantle without edge; and 0.8, 

 1.4, and 2.0 in mantle cavity fluid. In the same species ratios of heated 

 extract to extract of 3.4 and 7.2 were found in mantle edge; 4.8 in mantle 

 without edge; and 1.5 and 3.5 in mantle cavity fluid. Negligible activity in 

 some species (not hard clam) suggested that shell can be deposited in 

 absence of this enzyme. - J.L.M. 



610 



Fretter, V., and A. Graham. 1964. 



Reproduction. Chapter 4 in Physiology of Mollusca. Vol. 1. K. M. Wilbur 

 and C. M. Yonge (eds.) . Academic Press, New York, p. 127-164. 



V. mercenaria is the best example of a bivalve as a consecutive hermaphrodite, 

 which has a winter pause between 2 sex phases. (I think this is what he was 

 trying to say, although it is not clear because he uses vague terms like 

 "the former" and "this type".) "In Venus, as in Teredo diegensis, a very 

 small proportion of genuinely gonochoristic animals, both male and female, 

 occurs." Later, in discussing Ostrea, he says: "As in Venus and 

 T. diegensis , a small proportion of animals is not hermaphroditic." - J.L.M. 



611 



Friedl, Frank E. 1972. 



Amino acid deamination in the marine clam Mercenaria oampechiensis . Am. 

 Zool. 12(3): xxxii (abstract). 



Two pathways for deamination of L-amino acids have been observed in 

 southern quahog : one described as a dehydratase with at least L-Serine as 

 a substrate, the second of which may be a broadly specific oxidase acting 

 on L-Leucine. - J.L.M. 



612 



Fries, C ., and M. R. Tripp. 1976. 



Effects of phenol on clams. Mar. Fish. Rev. 38(10): 10-11. 



Gill and digestive tract epithelia are damaged by phenol at concentrations 

 of 1 ppm or greater for 24 hrs or longer. Gills showed moderate to 

 extensive epithelial necrosis, hemolymph sinuses were distended and 

 contained an amorphous precipitate. At higher concentrations of phenol 

 (10 ppm and up) damage was massive. Gut epithelia showed similar effects. 

 Posterior portions of hind gut epithelium did not appear to be quite as 

 sensitive. Other tissues showed variable effects. - J.L.M. 



613 



Fries, C. R., and M. R. Tripp. 1977. 



Cytological damage in Mercenaria mercenaria exposed to phenol. In Fate and 

 Effects of Petroleum Hydrocarbons in Marine Ecosystems and Organisms. Doug- 

 las A. Wolfe (ed.) . Pergamon Press, p. 174-181. (Ecosystems and Organisms on 

 title page. Organisms and Ecosystems on cover.) 



Adult clams were exposed to 1, 10, 100, 1000, 10000, 25000, and 50000 parts 

 per billion of phenol in artificial seawater (25°/ O0 ) for 24 hrs. Controls 

 were in artificial seawater. Gills, gut, digestive gland, and blood cells 

 (hemocytes) were damaged. Basophilic tissue staining was evident at lower 



170 



