Anagnostou, Christiana and Schubart, Christoph D. (2014) Morphometric characterisation of a population of adult coconut crabs Birgus latro (Decapoda: Anomura: Coenobitidae) from Christmas Island in the Indian Ocean. RAFFLES BULLETIN OF ZOOLOGY. pp. 136-149. ISSN 0217-2445,
Full text not available from this repository. (Request a copy)Abstract
Carapace and cheliped morphometry in sexually mature individuals of the coconut crab Birgus latro (Decapoda: Anomura: Coenobitidae) was analysed from six different locations on Christmas Island in the Indian Ocean in order to provide statistical evidence for heterochely and sexual dimorphism with regard to body size, cheliped size and heterochely. The absolute dimensions of weight, carapace length, cephalic shield length, thoracic length and width were significantly smaller in females than in males, confirming a pronounced sexual dimorphism in body size. For analysing intrasexual heterochely as well as sexual dimorphism with respect to cheliped size and heterochely, standardised values of the measured cheliped parameters corrected for size and allometric shape were used. For the allometric analyses of weight, and the cheliped propodus length and width, dactylus length, and merus length in relation to thoracic length, two statistical methods were applied and compared in order to identify the least error-prone method: A conventional linear Model II regression and a Model II non-linear analog of Reduced Major Axis Regression (RMA). Even though both methods resulted in the same pattern of allometry for the analysed parameters, the model fitted by the Model II non-linear analog of RMA regression mostly showed a better fit to the data. In both sexes, weight followed isometry. The cheliped parameters of females showed shallower allometric slopes than those of males. In both females and males, the dimension of the left cheliped parameters was significantly larger than that of the right (corresponding to the typical coenobitid heterochely), except for merus length in females. The standardised dimensions of the cheliped parameters as well as the degree of heterochely for all cheliped parameters were significantly larger in males than in females, providing evidence for a sexual dimorphism with respect to cheliped size and heterochely. Potential explanations for the evolution of heterochely and sexual dimorphism in B. latro are discussed.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | SEXUAL-SIZE DIMORPHISM; LARGE BODY-SIZE; MATE CHOICE; SPERM LIMITATION; RELATIVE GROWTH; SOUTHERN JAPAN; HATOMA ISLAND; HERMIT-CRABS; EVOLUTION; ALLOMETRY; morphometry; allometry; heterochely; sexual dimorphism; sexual selection; intersexual niche divergence |
| Subjects: | 500 Science > 590 Zoological sciences |
| Divisions: | Biology, Preclinical Medicine > Institut für Zoologie |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 05 Aug 2019 08:16 |
| Last Modified: | 05 Aug 2019 08:16 |
| URI: | https://pred.uni-regensburg.de/id/eprint/9029 |
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