Description of the larval morphology of captive reared Panulirus ornatus spiny lobsters, benchmarked against wild-caught specimens

The spiny lobster Panulirus ornatus is a high value seafood product in a number of South East Asian countries. However, this species is relatively rare in the wild compared to other Palinurid lobsters, and the development of an aquaculture sector for P. ornatus offers a potential avenue of matching supply with demand. To be a true sustainable farming sector it is essential that closed-life cycle production technology is developed. Recent efforts to complete the larval cycle of P. ornatus in captivity have resulted in repeated success and sufficient material to compile a complete morphological description of the larval (phyllosoma) phase. A morphological comparison is made between hatchery reared phyllosoma and specimens collected from the wild. The size of wild caught and captive reared phyllosomas did not differ significantly. However, it was noted that some hatchery reared individuals undergo truncated development with the ability to metamorphose in a shorter than expected time frame compared to estimates of wild phyllosomas. Observations are made on the plasticity of the larval duration in P. ornatus. Up to a total of 24 morphological increments were recorded in captive and wild P. ornatus phyllosoma. These were divided into 11 distinct stages by determining the commencement and completion of specific morphological traits. This descriptivemorphological key provides a singular reference point for monitoring larval development in this species. The variable nature of the larval duration of P. ornatus suggests that the optimisation of husbandry and nutrition conditions may significantly reduce the length of the hatchery phase and enhance the possibility of providing seedstock for an aquaculture industry based on closed-life cycle spiny lobster culture.