Acute and sub-chronic effects of sub-lethal cadmium exposure on energy metabolism in the freshwater shrimp, Paratya curvirostris

• Published in: Ecotoxicology and environmental safety 2017-01, Vol.135, p.60-67
• Main Authors: Chandurvelan, Rathishri, Marsden, Islay D., Gaw, Sally, Glover, Chris N.
• Format: Article
• Language: English
• Subjects: Animals; Bioenergetics; Cadmium; Cadmium - toxicity; Crustacean; Decapoda; Decapoda (Crustacea) - drug effects; Decapoda (Crustacea) - metabolism; Energy Metabolism - drug effects; Environmental Monitoring; Female; Fresh Water - chemistry; New Zealand; Nitrogen excretion; Oxygen consumption; Paratya curvirostris; Toxicity; Toxicity Tests, Acute; Toxicity Tests, Subchronic; Water Pollutants, Chemical - toxicity
• ISSN: 0147-6513; 1090-2414
• DOI: 10.1016/j.ecoenv.2016.09.018

Cadmium (Cd) is a toxic trace element enriched in waters through activities such as mining and agriculture. The freshwater shrimp Paratya curvirostris inhabits near-coastal, lowland streams potentially impacted by Cd, but nothing is known regarding its sensitivity to this metal. An acute (96h) median lethal concentration (LC50) of 405µgL−1 was derived for P. curvirostris, placing it among the most tolerant of freshwater shrimp species. Acute (4 d; 0, 50 and 100µgL−1) and sub-chronic (10 d; 0, 25 and 50µgL−1) exposures then investigated effects of Cd on energy metabolism (respiration rate, excretion rate, O:N ratio). In contrast to effects in previously studied species, Cd induced an increased respiration rate, which when coupled with an unchanged excretion rate, resulted in an increased O:N ratio. These data were explained by an increased reliance on carbohydrate and/or lipid as a metabolic substrate stimulated by increased metabolic costs of toxicant exposure. Similar effects were seen across all time-points, although the lowest effective Cd concentration decreased with increased exposure time. Overall, results suggest that Cd is unlikely to be a significant environmental stressor to P. curvirostris, except in highly contaminated freshwaters, and/or where Cd co-occurs with hypoxia. •An acute LC50 value of 405µgL−1 Cd was determined for Paratya curvirostris.•Subsequent sublethal exposures to Cd caused an increased respiration rate.•Nitrogen excretion rate was unchanged upon sublethal Cd exposure.•Results suggest that Cd exposure induces a change in metabolic substrate use.