Swimming energetics of the postlarvae of the spiny lobster Jasus edwardsii in New Zealand

Abstract

Postlarval spiny lobsters require sufficient energy reserves to enable them to actively move across the continental shelf and settle successfully in shallow coastal waters. Recent declines in settlement in lobster populations around the world have been associated with changing ocean climate impacts on the accumulation and use of energy reserves during this phase of the lifecycle. Here, we experimentally measured the energy requirements of swimming postlarvae of the Australasian red spiny lobster, Jasus edwardsii (Hutton, 1875). Wild-caught postlarvae actively swimming in tanks were found to have high energy demands, on average catabolizing 1.6 (SE 0.2) mg of lipid d–1, which is consistent with previous estimates for pueruli of this species using indirect estimations. In contrast, the protein reserves of experimentally swum pueruli only began to be used following the depletion of lipid reserves. A large observed difference in the nutritional condition of pueruli arriving at the sampling site between years is likely to translate into marked interannual differences in the survival and recruitment of pueruli into the population. To begin to understand the dramatic interannual fluctuations in the recruitment of spiny lobsters, it is necessary to determine the environmental factors leading to differences in nutritional condition of their pueruli. Differences in water temperature and zooplankton food availability that impact the ability of lobster larvae to accumulate nutrients appear to be likely candidates for closer examination in future studies.