Latitudinal and sex-specific differences in growth and an exceptional longevity for the Maori snapper Lutjanus rivulatus from north-western Australia

Abstract

Despite the Maori snapper, Lutjanus rivulatus, being a targeted fisheries species throughout its broad geographic distribution across the Indo-Pacific region, this is the first study of its age-based life history characteristics. Information on the age, growth and longevity of a species can improve our understanding of its inherent vulnerability to exploitation. In Western Australia (WA), this species is exploited on a small-scale over a broad area by commercial and recreational fishers. In the current study, L. rivulatus was estimated to attain an exceptional maximum age of 56 years from a total of 102 samples collected from the tropical waters of WA. The growth of this species was sexually dimorphic with males attaining a larger length-at-age than females. Further, the growth of both sexes varied in relation to latitude, and thus water temperature, with L. rivulatus in the cooler, higher latitudes attaining a greater length-at-age than individuals from the warmer, more northern regions at lower latitudes. This relationship between growth and water temperature is consistent with that predicted by the metabolic theory of ecology, and contributes toward knowledge of how the growth of this, and potentially other lutjanids, may respond to climate variability. The improved understanding of age-based demographics of this species also contributes to its broader sustainable management across the Indo-Pacific region.