Journal Molluscan Studies Advance Access originally published online on March 2, 2009
Journal of Molluscan Studies 2009 75(2):133-138; doi:10.1093/mollus/eyp002
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Effects of competition on size and growth rates of Caracolus caracolla (L.) in Puerto Rico
1Department of Biological Sciences, Bridgewater State College, Bridgewater, MA 02325, USA; and 2Center for Environmental Sciences and Engineering and Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, CT 06269, USA
Correspondence: C.P. Bloch; e-mail: cbloch{at}bridgew.edu
| Abstract |
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Although interspecific competition has been demonstrated between some pairs of terrestrial gastropod species, little work addresses its importance in tropical assemblages, which are often characterized by high species richness or population densities. A 9-year data set was used to assess growth rates and median shell size of a common Puerto Rican snail, Caracolus caracolla, as a function of density of conspecifics and potential interspecific competitors. Neither the rate nor the magnitude of growth of C. caracolla were inhibited at high densities. No association existed over time between density and size or growth rate. In contrast, C. caracolla generally was largest at sites with high densities of conspecifics. Several factors may be responsible for the apparent unimportance of competition, including the broad, flexible diet of C. caracolla, high productivity of the study site or periodic changes in microclimate or resource availability associated with hurricane-induced disturbance and recovery.
(Received 22 September 2008; accepted 16 December 2008)