Life-history characteristics of coral reef gobies. I. Growth and life-span

Life-history theory predicts that small species will exhibit short life-spans and fast growth rates; however, previous studies indicate that a positive relationship between size and maximum age may not be universally applicable to coral reef fishes. Here, we investigate the growth and life-span of 5 small species of coral reef goby (family Gobiidae): Istigobius goldmanni, Asterropteryx semipunctatus, Amblygobius bynoensis, Amblygobius phalaena and Valenciennea muralis. All 5 species were relatively short-lived, with the oldest individual sampled ranging from 11 to 16 mo depending on species and sex. Rapid growth occurred over much of the size range of all 5 species and, in contrast to most reef fishes, relatively little or no time was spent at an asymptotic size. Patterns of growth were best described by a Broken Stick model for L goldmanni, and by either a Broken Stick modi l or the von Bertalanffy growth function for the other 4 species. Summer-growing individuals had higher growth rates than winter-growing individuals, but this did not affect the overall patterns of growth. Sex-specific differences in growth were evident for L goldmanni and A. semipunctatus, with males growing faster and attaining a larger maximum size than females. In contrast, there was no significant difference in growth between male and female A. bynoensis, A. phalaena and V muralis. This pattern may be related to interspecific differences in intensity of sexual selection, mating system, and reproductive behaviour. Overall, the patterns of growth and life-span of these 5 small species conformed to traditional concepts of life-history theory.