Affiliation: | a Marine Research Laboratories, Tasmanian Aquaculture and Fisheries Institute, University of Tasmania, Nubeena Crescent, Taroona, Tasmania 7053, Australia b School of Aquaculture, Tasmanian Aquaculture and Fisheries Institute, University of Tasmania, Locked Bag 1-370, Launceston, Tasmania 7250, Australia c CSIRO Marine Research, GPO Box 1538, Hobart, Tasmania 7001, Australia |
Abstract: | The consequences of photothermal manipulation of reproduction in Jasus edwardsii broodstock on the morphology of newly hatched larvae and their biochemical characteristics were examined. The treatment of compressed temperature and photoperiod delayed the time of moult, mating and egg extrusion, but reduced the period until larval hatch, and reduced the hatching duration in individual females compared to the ambient treatment of simulated natural photoperiod and water temperature. Thus, the availability of phyllosoma for hatchery rearing was extended. However, the broodstock in the compressed treatment produced smaller phyllosoma and more larvae failed to develop beyond the naupliosoma stage than animals from the ambient cycle. Phyllosoma from the compressed treatment contained a higher proportion of polar and triacylglycerol lipid classes, lower wax esters, elevated levels of the essential fatty acid docosahexaenoic acid, a higher ratio of n-3/n-6 fatty acids, and lower levels of ascorbic acid. The changes in larvae from the compressed treatment may adversely affect their viability, and are probably due to the higher water temperatures experienced during late embryonic development. |