Effects of copper on the physiological responses of the commercial crab Lithodes santolla (Decapoda: Anomura) larvae

摘要

Effects of copper toxicity on zoea I of Lithodes santolla (Decapoda: Anomura) were analysed. The 96-h LC50 was estimated, resulting in 298.5 mu g L-1. Groups of larvae were exposed to sublethal concentrations (40, 80 and 160 mu g L-1) for 96 h. Oxygen consumption, ammonia excretion, O:N atomic ratio, lipid peroxidation (LPO) and body water content were measured. Oxygen consumption of treated groups (mean 46.92 +/- 8.03 mu g-atom O-2 h(-1) mg(-1)) did not differ significantly with control. Ammonia excretion decreased by 60% at higher Cu concentration (1.61 +/- 0.65 mu g-atom N-NH3 h(-1) mg(-1)), leading to a 117% increase in the O:N ratio. LPO values during the exposure time were higher in all treatments than in the controls. The water content was significantly higher in treatments than in controls. The highest concentration assayed, which represents about 50% of 96-h LC50, had evident effects on the parameters analysed. The values of copper in water reported for the coastal zone of Ushuaia bay. exceed the value established by the United States Environmental Protection Agency (USEPA) for ambient water quality criteria. Therefore, the results obtained in the present study are a contribution to the study of potential effects of copper as a common stressor in the first larval stage of this commercial species of the Beagle Channel.