Speaker
Description
Aquatic ecosystems are particularly exposed to urban and agricultural pollution. Importantly, some intestinal parasites, acanthocephalans, have the remarkable ability to accumulate pollutants from their host. These parasites could prove beneficial to their fish host if the benefits associated with pollutant sequestration, and thus the mitigation of ecotoxicological effects, outweigh the costs of parasitic infection. However, environmental pollution could also affect host-parasite interactions by inducing deleterious effects on parasite life history traits. We are studying the effect of pollutants on acanthocephalans, on chubs (Squalius cephalus, a widespread river fish) whether parasitized or not, as well as on host-parasite relationships between these two organisms. Experimental studies have been conducted in aquatic mesocosms of the CEREEP-ECOTRON IleDeFrance, adults chubs being exposed to different concentration of various pollutants, including pesticides (imidacloprid, carbendazim), and pharmaceuticals (paracetamol, diclofenac). We investigate how the presence of acanthocephalan parasites modifies pollutant accumulation in fish hosts, revealing contrasting responses depending on the pollutant considered. While these parasites can accumulate certain contaminants to the extent of reducing their concentrations in host tissues, this sequestration is not always sufficient to mitigate their adverse physiological and behavioral effects. Additionally, pollutants exposure induces damages in parasites, including potential effect on growth and reproduction. Overall, our results highlight that the role of acanthocephalans in polluted environments is more complex than simple pollutant sequestration. These findings emphasize the need to integrate host-parasite interactions into ecotoxicological risk assessment, as parasites can simultaneously alter contaminant dynamics and be themselves affected by pollution, with potential consequences for aquatic ecosystem functioning.
Key-words: Host-parasite interactions; Freshwater fish; Physiology; Pollutants
| Are you participating to the "AnaEE Environmental Rising Star Award "? | Yes |
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