MEPS 623:39-50 (2019)  -  DOI: https://doi.org/10.3354/meps13006

ABSTRACT: Spiny lobsters have an extended larval development in offshore waters that ends with the non-feeding post-larvae swimming across the continental shelf and settling in shallow coastal waters. We tested the hypothesis that recent declines in the recruitment of a number of spiny lobster populations in different parts of the world are the result of increasing coastal water temperatures that deplete the metabolic reserves of recently settled post-larvae. We examined the resilience of recently settled juvenile lobsters to the depletion of their reserves in 2 species of spiny lobster from temperate waters. Juveniles of Jasus edwardsii survived on average (±SE) for 34.44 ± 3.44 d without feeding at 19-21°C, while Sagmariasus verreauxi survived for 39.96 ± 1.40 d, with no differences in survival among 3 temperature regimes (17, 20 and 23°C). The point of no return for recently-settled juveniles of S. verreauxi was estimated to be 30.40 ± 13.50 d, which was close to their average survival under starvation conditions. Starved juvenile lobsters close to the point of no return with extremely low remaining protein and lipid (6.52% lipid and 27.18% protein of dry body mass) were capable of surviving once food was supplied. These results indicate that newly settled juveniles of spiny lobsters from temperate waters can endure adverse nutritional conditions over a wide range of thermal conditions for prolonged periods, making them resilient to future increases in water temperatures as a result of climate change.

KEY WORDS: Jasus edwardsii · Sagmariasus verreauxi · Point of no return · PNR · Starvation · Spiny lobster juveniles · Thermal tolerance