a1 Laboratoire des Interactions Ecotoxicologie Biodiversité Ecosystèmes (LIEBE) – CNRS UMR 7146, Université de Lorraine (UdL), Campus Bridoux, Bât. IBiSE, 8 Rue du Général Delestraint, 57070 Metz, France
In disturbed environments, infected organisms have to face both parasitic and chemical stresses. Although this situation is common, few studies have been devoted to the effects of infection on hosts' energy reserves and antitoxic defence capacities, while parasite survival depends on host survival. In this study, we tested the consequences of an infection by Polymorphus minutus on the energy reserves (protein, lipid and glycogen) and antioxidant defence capacities (reduced glutathione, γ-glutamylcysteine ligase activity) of Gammarus roeseli males and females, in the absence of chemical stress. Moreover, malondialdehyde concentration was used as a toxicity biomarker. The results revealed that in infected G. roeseli, whatever their gender and the sampling month, protein and lipid contents were lower, but glycogen contents were higher. This could be explained by the fact that the parasite diverts part of the host's energy for its own development. Moreover, glutathione concentrations and γ-glutamylcysteine ligase activity were both lower, which could lead to lower antitoxic defence in the host. These results suggest negative effects on individuals in the case of additional stress (e.g. pollutant exposure). In the absence of chemical stress, the lower malondialdehyde level in infected gammarids could imply a probable protective effect of the parasite.
(Received October 27 2011)
(Revised December 15 2011)
(Revised February 01 2012)
(Accepted February 01 2012)
(Online publication March 12 2012)
c1 Corresponding author: Laboratoire des Interactions Ecotoxicologie Biodiversité Ecosystèmes (LIEBE)–CNRS UMR 7146, Université de Lorraine (UdL), Campus Bridoux, Bât. IBiSE, 8 Rue du Général Delestraint, 57070 Metz, France. Tel: +33(0)387378500. Fax: +33(0)387378512. E-mail: email@example.com