Abstract
Shells of known-age Mya arenaria have revealed an internal annual growth pattern in this bivalve. The number of external growth rings on the shell exterior does not correspond to the age of the clams. This study provides an alternative method to using external annual rings for age determination. The internal growth lines are visible in thin sections when the shells are cut from the umbo to the ventral margin. The lines are formed by late spring of each year prior to spawning and are probably in response to decreased winter growth. When the 7 year olds were examined it was difficult to distinguish the most recent growth line and the inner shell layer. This could result in ages being underestimated. This annual pattern of internal growth lines could be useful to biologists and paleoecologists engaged in population studies.
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Literature Cited
Brousseau, D. J.: Analysis of growth rate in Mya arenaria using the Von Bertalanffy equation. Mar. Biol. 51, 221–227 (1979)
Craig, G. Y. and A. Hallam: Size-frequency and growth ring analysis of Mytilus edulis and Cardium edule and their paleoecological significance. Palaeontology 6, 731–750 (1963)
Farrow, G. E.: Periodicity structures in the bivalve shell: Experiments to establish growth controls in Cerastoderma edule from the Thames estuary. Palaeontology 14, 571–588 (1971)
Feder, H. M. and A. J. Paul: Age, growth and size-weight relationships of the soft-shelled clam Mya arenaria in Prince William Sound, Alaska. Proc. natn. Shellfish Ass. 64, 45–52 (1974)
Foster, R. W.: The genus Mya in the western Atlantic. Johnsonia. 2, 32–35 (1946)
Hanks, R. W.: The soft-shell clam. U.S. Fish and Wildlife Service. Circular 162, 16pp. 1963
Jones, D. S., I. Thompson and W. Ambrose: Age and growth rate determinations for the Atlantic surf clam Spisula solidissima (Bivalvia: Mactracea), based on internal growth lines in shell cross-sections. Mar. Biol. 47, 63–70 (1978)
Kennedy, W. J., J. D. Taylor and A. Hall: Environmental and biological controls on bivalve shell mineralogy. Biol. Rev. 44, 499–529 (1969)
Lammens, J. J.: Growth and reproduction in a tidal flat population of Macoma balthica (L.). Neth. J. Sea Res. 3, 315–382 (1967)
Lutz, R. A.: Annual growth patterns in the inner shell layer of Mytilus edulis L. J. Mar. Biol. Ass. U.K. 56, 723–731 (1976)
Mead, A. D. and E. W. Barnes: Observations on the soft-shell clam, Mya arenaria. Rep. Rhode Isl. Comm inld Fish. 22, 29–46 (1903)
Newcombe, C. L.: Growth of Mya arenaria in the Bay of Fundy region. Can. J. Res. 13, 97–137 (1935)
Newcombe, C. L.: Validity of concentric rings of Mya arenaria for determining age. Nature Lond. 137, 191–192 (1936)
Nye, O. B., D. A. Dean and R. W. Hinds: Improved thin section techniques for fossil and Recent organisms. J. Pal. 46, 271–276 (1972)
Pannella, G. and C. MacClintock: Biological and environmental rhythms reflected in molluscan shell growth. J. Pal. 23, 577–594 (1968)
Rhoads, D. C. and G. Pannella: The use of molluscan shell growth patterns in ecology and palaeoecology. Lethaia 3, 143–161 (1970)
Stafford, J.: On the recognition of bivalve larvae in plankton collections. Contr. Canad. Biol. 1906–1910 (1912)
Stevenson, J. A. and L. M. Dickie: Annual growth rings and rate of growth of the giant scallop Placopecten magellanicus (Gmelin) in the Digby area of the Bay of Fundy. J. Fish. Res. Bd Can. 11, 660–671 (1954)
Sullivan, C. M.: Bivalve larvae of Malpeque Bay, P. E. I. Bull. Fish. Res. Bd Can. 72, 1–36 (1948)
Swan, E. J.: Growth indices of the clam Mya arenaria. Ecology. 33, 365–374 (1952)
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Communicated by I. Morris, West Boothbay Harbor
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MacDonald, B.A., Thomas, M.L.H. Age determination of the soft-shell clam Mya arenaria using shell internal growth lines. Mar. Biol. 58, 105–109 (1980). https://doi.org/10.1007/BF00396121
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DOI: https://doi.org/10.1007/BF00396121