Estimation of the Abundance and Population Structure of the Purple Snail Plicopurpura pansa (Gould, 1853) Comparing Two Methods

ABSTRACT

A study using a mark-recapture method was used in order to estimate the abundance and population structure of the Purple snail Plicopurpura pansa (Gould, 1853), on a rocky shore in Tenacatita Bay, Jalisco, Mexico. A comparison of the results obtained by this method and the linear transects parallel to coast was performed, the latter has been the method most commonly used in previous studies for this species. The results indicate significant differences in estimates of population parameters obtained by the two methods used; we found that in a general of linear transection methods tend to underestimate the abundance of these snails. Given the implications of these findings for the management of a species with potential for exploitation, such as the Purple snail, we discuss the possible causes and significance of this discrepancy of the methods.