Hostname: page-component-cd9895bd7-p9bg8 Total loading time: 0 Render date: 2024-12-28T15:54:02.521Z Has data issue: false hasContentIssue false

Relative Growth of the abdomen and the carapace of the Shore-Crab Carcinus maenas*

Published online by Cambridge University Press:  11 May 2009

J. S. Huxley
Affiliation:
King's College, London
O. W. Richards
Affiliation:
Imperial College of Science and Technology, London.

Extract

1. In regard to relative abdomen-breadth and relative carapace-breadth, the common shore-crab Carcinus maenas in both sexes exhibits a continuous change of proportions throughout life, from small animals of 2 mm. carapace-length to the largest obtainable (over 50 mm. carapace-length).

2. The parts measured exhibit constant differential growth-ratios (growth-coefficients) relative to carapace-length taken as standard, over long periods of the life-history.

3. The approximate growth-coefficients are as follows, relative to carapace-length:

Carapace-breadth, 1·06. This appears to be constant throughout the range of size measured, with a possible decline to nearly unity at large sizes.

Abdomen-breadth.

Crabs unsexable externally (2–6 mm. carapace-length), 1·26.

Females: early phase, 1·26; late phase, 1·42.

Males: early phase, 1·07; late phase, 0·94.

The early phase begins as soon as the sexes can be distinguished. The onset of the late phase may be presumed to be correlated with sexual maturity. In females it occurs certainly between 17 and 20 mm. carapace-length, in males between 14 and 29 mm.

4. There are indications of seasonal and local differences in relative abdomen size.

5. Feeding crabs of 9 to 22 mm. carapace-length solely on fresh ox-thyroid or fresh ox-pituitary for periods up to a year produces no change in growth-rate or in secondary sexual characters as against controls fed on fresh fish.

Type
Research Article
Copyright
Copyright © Marine Biological Association of the United Kingdom 1931

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

LITERATURE CITED

Atkins, D. 1926. The moulting stages of the Pea-crab (Pinnotheres pisum). Journ. Mar. Biol. Assoc., N.S., Vol. XIV, p. 475493.CrossRefGoogle Scholar
Huxley, J. S. 1924. The variation in the width of the abdomen in immature Fiddler-Crabs considered in relation to its relative growthrate. Amer. Nat., 58, pp. 468475.CrossRefGoogle Scholar
Huxley, J. S. 1927. Further work on Heterogonic Growth. Biol. Zentralbl., 47, pp. 151163.Google Scholar
Huxley, J. S. 1931. Notes on Differential Growth. Amer. Nat., 65, pp. 289315.CrossRefGoogle Scholar
Morgan, T. H. 1923. Further evidence on variation in the width of the abdomen in immature Fiddler-Crabs. Amer. Nat., 57, pp. 274283.CrossRefGoogle Scholar
Romeis, B. 1925. Experimentelle Untersuchungen über die Wirkung von Wirbeltierhormonen auf Wirbellose. 2. Der Einfluss der Schilddrüsenfütterung auf die Kohlehydratstoffwechsel des Flusskrebses (Astacus fluviatilis). Arch. Entw. Mech., 105, pp. 778816.CrossRefGoogle Scholar
Shaw, M. E. 1928. A contribution to the study of relative growth of parts in Inachus dorsettensis. Br. J. Exp. Biol., 6, p. 145.CrossRefGoogle Scholar
Smith, G. W. 1906. Rhizocephala. Fauna u. Flora des Golfes von Neapel, 29.Google Scholar