Examination of shell repair in the Recent gastropod species Cerithium stercusmuscarum from several microhabitats within Bahia la Choya, Sonora, Mexico reveals significant intraspecific variation in shell repair frequencies. Samples include approximately 800 individual gastropods from four distinct localities: two rocky and two sandy intertidal habitats. Biometric measurements and the number of scars on the last whorl were used to statistically investigate the relationships between size, habitat and shell repair.
Shell repair frequencies vary significantly between the microhabitats examined, and this variation is not related to differences in size-frequency distributions between samples. There is no preference for either larger or smaller snails to be attacked in any sample.
Trends in gastropod shell repair frequency provide a method of examining predator-prey relationships through time. However, potential problems, including microhabitat-related intraspecific variation in repair frequency, exist in interpreting repair trends. The results of this study demonstrate that there is significant variation in shell repair frequency through space at any one point in time. Intraspecific variation could, therefore, blur any overall trend in shell repair frequency through time.