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Metric variations in populations of Carcinus moenas

Published online by Cambridge University Press:  11 May 2009

G. Williams
Affiliation:
Zoology Department, theQueen's University of Belfast
A. E. Needham
Affiliation:
Zoology Department, theQueen's University of Belfast

Extract

1. Measurements of Carcinus, comparable to those taken by Weldon at Plymouth 40 years ago, have been made on material from three Irish localities, the observations in each area extending over three years. The three localities afford different environments, one having no silt, one a moderate amount and the other much silt.

2. The results support the view that the change in the ratio frontal width/ carapace length with increase in body size is due to differential growth in the individual and is not caused, as Weldon supposed, by the continuous removal through natural selection of those crabs with a relatively wide frontal aperture. Measurement on the growth of individuals confirms this view.

3. A striking fact which emerged from Weldon's work was that the ratio mentioned above showed a successive diminution in each of the three years covered by the observations. A precisely similar diminution has been found at each of the Irish localities, and it is shown that the annual differences are mathematically significant.

4. The results disprove Weldon's hypothesis that the change in the ratio is correlated with the slow accumulation of silt in Plymouth Sound. The Irish locality with most silt has the widest frontal aperture and the intermediate locality the narrowest. It is also shown that the yearly trend towards a lower value for the ratio cannot be continuous, for the rate of change is too rapid to be maintained indefinitely, and the values obtained in the Irish localities overlap those at Plymouth 40 years earlier. Possible explanations of the changes are discussed.

5. The differences between populations from the three localities in any year are much less marked than the annual differences at one locality, and are not generally significant. Though small, however, they do show a consistent sequence among the three localities (but not corresponding to the order for siltiness).

Type
Research Article
Copyright
Copyright © Marine Biological Association of the United Kingdom 1941

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References

REFERENCES

Cunningham, J. T., 1928. Modern Biology, pp. 189–99. London.Google Scholar
Davenport, C. D., 1934. Critique of curves of growth and of relative growth. Symposia on Quantitative Biology, Vol. 2, Cold Springs Harbor, pp. 203–8.CrossRefGoogle Scholar
Day, J. H., 1935. Heterogonic growth in the abdomen of Carcinus moenas. Rep. Dove Marine Laboratory (3rd Series, No. 3).Google Scholar
Dice, L. R., 1940. Ecological and genetic variability within species of Peromyscus. Amer. Nat., Vol. 74, pp. 212–21.CrossRefGoogle Scholar
Elton, C. S., 1924. Periodic fluctuations in numbers of animals. Brit. Journ. Exp. Biol., Vol. 2, pp. 119–63.CrossRefGoogle Scholar
Huxley, J. S., 1932. Problems of Relative Growth. London.Google Scholar
Huxley, J. S. & Teissier, G., 1936. Terminology in Relative Growth. Nature, Vol. 137, p. 780.CrossRefGoogle Scholar
Kemp, S., 1938. Oceanography and the fluctuations in the abundance of marine animals. Rep. Brit. Ass. Sci., Section D, Zool., pp. 85101.Google Scholar
Lumer, H., 1939. The dimensions and interrelations of the relative growth constant. Amer. Nat., Vol. 73, pp. 339–46.CrossRefGoogle Scholar
Needham, A. E., 1935. An application of the principle of heterogony. Nature, Vol. 136, p. 433.CrossRefGoogle Scholar
Needham, A. E., 1937. On relative growth in Asellus aquaticus. Proc. Zool. Soc. Lond., A, Vol. 108, pp. 289313.CrossRefGoogle Scholar
Orton, J. H., 1936. Rate of growth in decapods. Journ. Mar. Biol. Assoc. Plymouth, Vol. 20 (3), pp. 673–90.CrossRefGoogle Scholar
Reeve, E. C. R., 1940. Relative growth in the snout of anteaters. Proc. Zool. Soc. Lond., Vol. 110, A, pp. 4780.CrossRefGoogle Scholar
Teissier, G., 1934. Sur la croissance du cephalothorax de Portunus. Bull. Soc. Zool. Fr., Vol. 59, pp. 200–2.Google Scholar
Teissier, G., 1935. Les procédés d'étude de la croissance relative. Bull. Soc. Zool. Fr., Vol. 60, pp. 292307.Google Scholar
Teissier, G., 1936. Formes locales dune même espèce. Mem. Mus. Hist. Nat. Belg., (2), Vol. 3, pp. 627–34.Google Scholar
Weldon, W. F. R., 1894. Selective destruction of Carcinus moenas with respect to a particular dimension. Proc. Roy. Soc., Vol. 57, pp. 360–82.Google Scholar
Weldon, W. F. R., 1898. Natural selection in the shore crab, Carcinus moenas. Rep. Brit. Ass. Sri., Bristol, Section D, pp. 887902.Google Scholar