Reproductive responses to shell damage by the gastropod Nucella emarginata (Deshayes)

Abstract

This study investigated the effects of shell injury on reproduction by the marine intertidal snail Nucella emarginata (Deshayes) in northern California. Snails with experimentally damaged shells grew significantly more new shell than did control snails, and fed-damaged snails grew more shell than starved-damaged snails. The repair rate difference between fed and starved snails indicates that shell repair is an energetically costly process. Despite this, shell-damaged female snails produced more egg capsules than uninjured females, indicating an increase in reproductive effort. However, total production of embryos per female did not differ among treatments. A mark-and-recapture experiment showed that shell-damaged snails had higher rates of mortality than did uninjured snails. These results are consistent with a life-history model which predicts that reproductive effort should increase when adult mortality rises relative to juvenile mortality.