You are not currently logged in.
Access your personal account or get JSTOR access through your library or other institution:
If You Use a Screen ReaderThis content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Thermoregulation as an Alternate Function of the Sexually Dimorphic Fiddler Crab Claw
M. Zachary Darnell and Pablo Munguia
The American Naturalist
Vol. 178, No. 3 (September 2011), pp. 419-428
Stable URL: http://www.jstor.org/stable/10.1086/661239
Page Count: 10
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Preview not available
AbstractFiddler crabs are highly sexually dimorphic. Males possess one small (minor) feeding claw and one greatly enlarged (major) claw; females possess two small claws. The major claw is used to attract mates and for burrow defense, but it is costly for the male to possess. We tested the hypothesis that the major claw also functions as a thermoregulatory structure, a function that would allow males to spend a greater amount of time at the surface, foraging and attracting potential mates. Fiddler crabs Uca panacea were exposed to a source of radiant heat and body temperatures were monitored. Four groups of crabs were tested: intact males, males with the minor claw removed, males with the major claw removed, and females. The body temperatures of males without the major claw increased more rapidly and reached higher values than did those of males with the major claw intact, but the results from these animals were similar to those of females. These results support the hypothesized thermoregulatory function of the major claw. The major claw may function as a heat sink, transferring heat away from the body and dissipating it into the air. Enhanced thermoregulatory ability provided by the major claw may partially ameliorate the energetic costs of possessing such a large claw.
© 2011 by The University of Chicago. All rights reserved.