The effects of temperature, soil moisture and UV radiation on biomarkers and energy reserves of the isopod Porcellionides pruinosus

Abstract

Terrestrial isopods from the species Porcellionides pruinosus were exposed to different ranges of temperature, soil moisture content and doses of UV radiation. For the temperature and soil moisture content experiments, organisms were sampled after 48h, 96h and 14days of exposure, whereas in the UV experiment, they were sampled at the end of the exposure periods, that consisted on a single-pulse with duration ranging from 30min to 8h. For each sampling time the acetylcholinesterase, glutathione S transferases, glutathione peroxidase and catalase activities were determined, as well as lipid peroxidation rate. Energy content (lipids, carbohydrates, proteins) and other energy related parameters: energy available, energy consumption and cellular energy allocation were also determined, along with mortality.The results obtained showed that increases in temperature will affect life traits and specific strategies for isopods to manage their energy budget, in order to handle oxidative stress. It also showed that this species is acclimated to lower moisture scenarios, whereas in case of flood scenarios the turnover point between optimal conditions and mortality is very narrow, which may lead to the local extinction of populations in specific micro-habitats. This study also showed that UV radiation also poses an important stressor for isopods that should be taken in consideration, as the actual doses nowadays present significant negative impact on these organisms.The study also emphasises that the effects of abiotic factors should be included and taken into consideration by policymakers and that the inclusion of abiotic effects in ecotoxicological tests should be included in the analysis of any stressor to improve chemical risk assessment.