*Department of Zoology, University of Texas, Austin, TX 78712, USA
Morphology and muscle stress of chelae of temperate and tropical stone crabs Menippe mercenaria
Article first published online: 23 MAR 2009
Journal of Zoology
Volume 215, Issue 4, pages 663–673, August 1988
How to Cite
Blundon, J. A. (1988), Morphology and muscle stress of chelae of temperate and tropical stone crabs Menippe mercenaria. Journal of Zoology, 215: 663–673. doi: 10.1111/j.1469-7998.1988.tb02402.x
- Issue published online: 23 MAR 2009
- Article first published online: 23 MAR 2009
- Accepted 9 September 1987
Chela morphology and muscle stress were compared between temperate and tropical populations of stone crabs Menippe mercenuriu (Say) to test whether environmental differences might result in greater crushing strength in the tropics. Such differences include increased crab diversity in the tropics (which might lead to greater fighting among congeners), increased prey exoskeleton calcification in the tropics, and year round chela use in the tropics as opposed to seasonal chela use in the temperate population.
No latitudinal differences were found in any aspect of chela morphology, including relative chela size, mechanical advantage, apodeme surface area, and angle of muscle fibre pinnation. Summer measurements of crusher chela muscle stress were also similar between the two populations.
The maximum muscle stress determined for M. mercenariu was 220 N ∼r n -∼, much higher than stress levels previously reported for crustaceans. Other researchers have typically measured forces either from autotomized chelae or by measuring forces required to open a closed chelae. I have determined muscle stress using a force transducer that measures active gripping strength in live crabs.