Growth and reproduction of the painted spiny lobster (Panulirus versicolor) on the Great Barrier Reef (Australia)

Abstract

Eighty adults of the painted spiny lobster (Panulirus versicolor) from Northwest Island (Great Barrier Reef, Australia) were captured by hand, internally tagged with elastomer, and subsequently released. Forty-three individuals were recaptured after 6, 12, 18 or 24 months at liberty, giving an overall recapture rate of 54%. Ovigerous female lobsters were captured in both summer and winter, suggesting this species has a protracted spawning period. Although some females reproduced in situ, the majority of mature females appeared to emigrate during summer, resulting in a male-biased local population. Overall sex-ratios, however, did not differ from unity during the study period. Moult interval was estimated to be 131–284 days and was found to increase with body size. Growth increment was estimated to be 2–3 mm (carapace length) and appeared to be constant across the range of sizes examined (98–153 mm carapace length). Growth rate was asymptotic, with the lifetime growth trajectory of P. versicolor well defined by a von Bertalanffy growth model (L∞ = 144.7 mm; K = 0.27 year−1; t0 = −0.18 year). In general, growth of P. versicolor was similar to other tropical Palinurids, but markedly faster than temperate Palinurids. The growth parameters and reproductive dynamics reported here will be valuable for optimizing population models and management strategies for this valuable fishery resource.