Comparison of three shredders response to acute stress induced by eucalyptus leaf leachates and copper: single and combined exposure at two distinct temperatures

¹ IMAR & Department of Life Sciences, University of Coimbra, 3004-517 Coimbra, Portugal
² CIIMAR – Interdisciplinary Centre of Marine and Environmental Research, Laboratory of Ecotoxicology and Ecology, University of Porto, Rua dos Bragas, 289, 4050-123 Porto, Portugal
³ ICBAS – Institute of Biomedical Sciences of Abel Salazar, Department of Populations Studies, Laboratory of Ecotoxicology, University of Porto, Rua Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal

^* Corresponding author: ana.gama@ci.uc.pt

Received: 15 May 2013
Accepted: 8 January 2014

Abstract

The objectives of this study were to compare the sensitivity of three freshwater macroinvertebrate shredder species (Atyaephyra desmarestii, Echinogammarus meridionalis and Schizopelex festiva) to acute stress induced by eucalyptus leaf extracts and copper, independently and in mixtures, and the ability of temperature to influence the chemicals’ toxicity. Laboratory bioassays based on mortality with single substances and mixtures were carried out with the three species at 10 and 20°C. After 96 h of exposure, S. festiva, A. desmarestii and E. meridionalis were found to have differences of sensitivity to copper, eucalyptus leaf extracts and their mixtures, with S. festiva being the least sensitive species at both 10 and 20°C. The relative sensitivity of A. desmarestii and E. meridionalis to chemical exposure seems to be chemical and temperature dependent. Overall, these findings suggest that chemical stress may modulate the biodiversity of stream shredders communities due to differential sensitivity of individual species to environmental contaminants, and that temperature may influence the process. Thus, more knowledge on the combined effects of multi-stressors is needed, particularly on temperature and chemicals’ interactions and on the molecular mechanisms underlying the responses observed at individual level.