Patterns of growth, longevity and recruitment of intertidal limpets in New South Wales

Abstract

Six species of limpets, representing the families Acmaeidae, Fissurellidae, and Siphonariidae, were investigated. Size-frequency distributions were obtained regularly for each species, and provided data on rates of growth and mortality of age cohorts, and on the time and intensity of recruitment of juveniles into the population. Where possible, rates of growth and mortality were also obtained from individually marked animals, and data on recruitment were obtained by regular monitoring of permanently marked out quadrats. The usefulness of information gained by the two methods for determining rates of growth and mortality is compared. All species showed indeterminate growth and great variability in mortality and recruitment. The possession of iteroparity and early reproductive maturity may partially compensate for this variability and unpredictability in growth, longevity and recruitment. The differences between species within the same genus can be as great as the differences between families, however, and it is not meaningful to consider further generalisations concerning life history characteristics.