Reproduction in the tropical rock lobster Panulirus ornatus in captivity

The Australian spiny lobster fishery is Australia's most economically valuable fishery, presently worth around $450 million per annum (Anon., 2008a). However, while many are currently well managed, most Australian spiny lobster fisheries are at their maximum sustainable capacity whilst demand for lobster continues to increase (Jones, 2009a). Globally, spiny lobster catch rates have stabilised or even declined since 2002 (FAO, 2007; 2009). Furthermore, due to anthropogenic perturbations, wild fishery production may actually drop significantly as highlighted by recent projections for western rock lobster catch and marked decreases in catch per unit effort (CPUE) for may lobster species (Anon., 2008b; FAO, 2009). The only real potential for significant production growth appears to be through aquaculture. Internationally, lobster aquaculture to date has consisted of capturing juvenile wild seed stock for on-growing to market size (Jones, 2009b). However, the long-term viability and sustainability of spiny lobster aquaculture depends on closing the life cycle and developing an economically viable method for raising lobsters from eggs through to market size (Grove-Jones et al., 2002). The ornate spiny lobster (Panulirus ornatus) has been identified as having clear commercial potential, largely due to its abbreviated life history compared to other spiny lobster species (Grove-Jones et al., 2002; George, 2005). More specifically, its relatively short larval phase (4 months) and fast juvenile growth rate make it a suitable candidate for commercial aquaculture if techniques and technologies, to consistently produce large numbers of juveniles from eggs, are developed. A Fisheries Research and Development Corporation (FRDC) commissioned review (Grove-Jones et al., 2002) stated that development of viable puerulus production technology for lobsters would be a 5+ year prospect, which should be addressed through three discrete phases to most effectively achieve the commercialisation of spiny lobsters in Australia (see Chapter II). The experiments carried out as a part of this study address phase I as specified by the Grove-Jones et al. (2002). This work fills important knowledge gaps previously unknown for this species, in brief, the major findings include: 1. The control of breeding, gonad development, moulting and egg extrusion though the photoperiodic and water temperature manipulation. In particular, that the lengthening of photoperiod is the cue to gonad development and breeding for this species. 2. The optimal egg incubation temperature defined for this species and a model to predict the hatch timing and developmental period of embryos when incubated at a range of temperatures. 3. Techniques to quantitatively assess phyllosoma quality at hatch, including the development of a ten minute salinity stress test. 4. Larval husbandry techniques to achieve high growth and survival through to phyllosoma stage V. These findings are important towards the development of hatchery technology and commercialisation for P. ornatus. Ultimately, these findings are fundamental to successful puerulus culture. Results from these studies have made a significant contribution to the culture for P. ornatus within Australia. Furthermore, they have formed the foundation of continuing successful work in the area of rock lobster larval rearing which has resulted in the completion of the larval cycle of Panulirus ornatus in captive culture