96 



97 



93 



Ansell, A. D. 1968. 



The rate of growth of the hard clam Meraenaria meraenaria (L) throughout the 

 geographical range. J. Cons. 31: 364-409. 



Published data on growth of hard clam throughout its geographical range are 

 reviewed and data transformed for comparative purposes. Local variation in 

 annual growth is extreme and is more or less the same throughout the con- 

 tinuous range of the species. Growth occurred only in summer in the northern 

 part of the range, and throughout the year in the southern part. Optimum 

 temperature for growth was 20 °C and no growth occurred below 9°C or above 

 31°C. The relationship of growth and temperature appeared similar throughout 

 the species geographical range. Deviations from the growth- temperature 

 relationship were interpreted as the effect of other factors such as food 

 availability on growth. Data for growth of Meraenaria campeahiensis and 

 M. meraenaria X M. campeehiensis hybrids are presented. Growth in these 

 clams increases with increasing temperature in the range 10-30°C. - D.L. 



Ansell, Alan D. 1969. 



Thermal releases and shellfish culture: Possibilities and limitations. 

 Chesapeake Sci. 10(3-4): 256-257. 



Development of intensive shellfish cultivation requires 1) a reliable 

 source of seed, 2) systematic optimum conditions of culture for maximum 

 yield, and 3) application of techniques like selective breeding to improve 

 the stock. Use of waste heat may contribute to requirement 2. Warm water 

 can be used to provide an extended, or even continuous, growing period. 

 Observations on Meraenaria meraenaria at Poole, Dorset, and nearby control 

 areas has shown that for most of the year growth was limited by factors 

 other than temp, the most important of which was availability of suitable 

 planktonic food. The main effect of increased temp was to allow the 

 animal to utilize more effectively peaks of plankton biomass which occur 

 at times when normally clam activity was reduced. Thus, while irrigation 

 by warm water simulated conditions typical of areas farther south, the 

 water mass as a whole was not similarly affected, and the seasonal cycle 

 of phytoplankton biomass characteristic of inshore boreal waters remained 

 a limiting factor. Excess food was present only for short periods, and at 

 times food supply was insufficient to serve maintenance needs of clams at 

 higher temp. From Oct to Feb clams did not grow even at temps over 10 °C, 

 and body weight fell. Optimum temp for shell growth was 20°C but condition 

 increased at lower temps, with optimum about 14°C. Thus, at optimum temp 

 for shell growth, meat yield may be decreased. Full potentiality of warm- 

 water culture may be achieved only with supplemental feeding, e.g., thermal 

 and nutrient enrichment are necessary. Growing and fattening may require 

 separate stages of culture. More rapid glycogen accumulation might be 

 obtained by controlled use of non-living food. Limitations of power plant 

 operation must be considered: water supply may be discontinuous and temp 

 may vary. Annual temp range may be extended to include higher summer temps 

 but retaining normal winter temps. Diurnal temp fluctuation may be greater 

 and abrupt temp changes more frequent than in nature. Thus, the species 

 used must have high temp tolerance. Another constraint is use of chemicals 

 to prevent fouling in the power plant. Other incidental additions, such as 

 heavy metals and radionuclides, must be expected. - J.L.M. 



Ansell, Alan D. 1977. 



The adenosine triphosphate content of some marine bivalve molluscs. J. 

 Exper. Mar. Biol. Ecol . 28 (3): 269-283 . 



Total ATP (adenosine triphosphate) content of representatives of 23 bivalve 

 families varied from 1.26 to 0.26% of dry tissue weight. Four members of 

 family Veneridae were examined, but not Meraenaria meraenaria. ATP content 

 of these 4 varied from 0.18 to 0.82% of dry tissue. Highest values were in 

 muscle tissues. High maintained levels of ATP were associated with ability 

 of species to use energy rapidly for short periods, such as in escape 

 responses. Thus, some families have consistently more than average, and 

 some consistently less than average ATP values. - J.L.M. ■ 



27 



