Abstract
DURING last August a female edible crab (Cancer pagurus) showing an interesting abnormality was brought into the Plymouth Aquarium and Dr. E. J. Alien, the director, very kindly handed it to me for examination. As will be seen from the accompanying illustrations, the abnormal region is the abdomen, wliich is exceptionally long and wide, and resembles that of a hermit crab in being twisted towards the right, and in that the pleopods are shorter on the right side than on the left. On the sixth abdominal segment (which bears the uropods in most decapods, but in crabs is usually limbless) there is, on the right side, a supernumerary limb composed of a protopodite, a stumpy endopodite and a two-jointed exopodite which ends as a hard, black claw. Although the general plan is thus that of a uropod, the limb resembles a walking leg in the shape of the joints, thickness of the cuticle, hairiness and particularly in the claw, which is better developed than that of any hermit crab.
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References
Bethe, Arch. Ent. Mech., 3, 301; 1896.
Huxley and Richards, J. Mar. Biol. Assoc., 17, 1001; 1931.
Huxley, “Problems of Relative Growth”, London 1932.
Pearson, L.M.B.C. Memoir, No. 16, Cancer. London 1908.
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YOUNG, J. Extra Legs on the Tails of Crabs. Nature 132, 785 (1933). https://doi.org/10.1038/132785a0
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DOI: https://doi.org/10.1038/132785a0
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