Size-frequency distributions and size-survivorship curves were constructed for the following seven species of living gastropods from Bahia la Choya: Cerithidea
luteofasciatus and Tegula
rugosa. Size-frequency distributions and size-survivorship curves of empty shells of Cerithidea
mazatlanica and Cerithium
stercusmuscarum were constructed to evaluate the effects of taphonomic processes on survivorship curves.
All size-survivorship curves are convex-up in shape: small size classes show low mortality and mortality increases with increasing size. Despite post-mortem processes, survivorship curves for empty shells mimic the shape of curves based on live individuals.