Starvation and recovery ability of phyllosoma of the tropical spiny lobsters Panulirus ornatus and P. homarus in captivity

The ability of planktonic crustacean larvae to survive initial periods of starvation is highly dependant on maternally provisioned endogenous reserves. For many lobster species lecithotrophic development is not common and feeding is required at some stage soon after hatching and during the first intermoult period. While the impact of providing or withholding feed on larval development has been examined in a number of temperate and sub-tropical spiny lobsters, such as Jasus edwardsii, J. verreauxi and Panulirus japonicus, less is known about tropical lobster species. This study examined the influence of starvation and feeding on the dry weight (dw), intermoult duration, point of no return of 50% (PNR50) and point of reserve saturation of 50% (PRS50) in the tropical spiny lobster spp. Panulirus ornatus and P. homarus. In both species, continuous feeding or starvation from hatch resulted in a doubling in initial dw or a reduction of 20%, respectively. Starvation of larvae resulted in a PNR50 for both species of 5.9 days, with no significant reduction in the ability to moult when starved for between 4-5 days. Moulting commenced after 5-6 days of feeding in both species. A delay in moulting was equivalent to the initial duration of starvation of up to a total of 4 days. The PRS50 was 3.8 and 4.4 days for P. ornatus and P. homarus respectively. Moulting was severely curtailed if phyllosomas were fed for < 3 days. The ability to maintain survival and growth after bouts of starvation indicates that phyllosomas in the wild can have significant temporal plasticity with a consequential variation in the total length of their larval period. The implications for commencing or withholding first feeds with respect to PNS50, PRS50, larval duration and development are discussed, with emphasis on the development of appropriate aquaculture hatchery technology.