01629nas a2200205 4500008004100000245010700041210006900148300001200217490000700229520095800236653001801194653002501212653003201237653003301269100001601302700001901318700001601337700001901353856005101372 2011 eng d00aZebra Mussel (Dreissena polymorpha) Parasites: Potentially Useful Bioindicators of Freshwater Quality?0 aZebra Mussel Dreissena polymorpha Parasites Potentially Useful B a665-6730 v453 a

In environmental quality bioassessment studies, analysis of host–parasite interactions may well be a valuable alternative to classical macroinvertebrate sampling approaches. Herein, we investigated whether zebra mussel (Dreissena polymorpha) parasites could be useful biomonitoring tools. Mussel populations were sampled twice at two sites in northeastern France representing different levels of contamination and were characterized for parasite infection following standard histological methods. Our results indicated that sites of different environmental quality (i.e. chemical contamination) exhibited different parasite communities characterized by different trematode species and parasite associations. An additional significant finding was the positive correlation established between the prevalence of Rickettsiales-like organisms and metal contamination. Multivariate analyses were valuable in examining parasite communities.

10aBioassessment10aDreissena polymorpha10aEnvironmental contamination10aHost–parasite interactions1 aMinguez, L.1 aMolloy, D., P.1 aGuerold, F.1 aGiamberini, L. uhttp://dx.doi.org/10.1016/j.watres.2010.08.02801928nas a2200205 4500008004100000245014100041210006900182300001200251490000800263520124600271653001501517653002501532653003201557653001401589100001601603700001401619700001901633700001901652856005101671 2009 eng d00aInteractions between Parasitism and Biological Responses in Zebra Mussels (Dreissena polymorpha): Importance in Ecotoxicological Studies0 aInteractions between Parasitism and Biological Responses in Zebr a843-8500 v1093 a

Given that virtually all organisms are hosts for parasites, the investigation of the combined effects of contamination and parasitism is important in the framework of aquatic bioindication procedures. To assess the impact of such multistresses at the host cellular level, we sampled parasitized zebra mussel (Dreissena polymorpha) populations from two sites in northeast France that presented different levels of contamination. Experimental groups were formed based on parasite species and host gender and tested by histochemistry and automated image analysis for biological responses, such as structural changes of the lysosomal system and neutral lipid accumulation. Infected organisms displayed smaller and more numerous lysosomes compared with uninfected congeners, and infection further elevated the effect of the chemical contamination on this biomarker. In contrast, co-infection of females with selected parasites did produce inverse results, i.e. a more developed lysosomal system and neutral lipid depletion. Our data, therefore, suggest that parasitism in zebra mussels represents a potential confounding factor in ecotoxicological studies and must be taken into account in environmental risk assessment studies.

10aBiomarkers10aDreissena polymorpha10aEnvironmental contamination10aParasites1 aMinguez, L.1 aMeyer, A.1 aMolloy, D., P.1 aGiamberini, L. uhttp://dx.doi.org/10.1016/j.envres.2009.07.012