The language of abiotic stress in aquatic animals : molecular characterisation of stress metabolite-mediated stress communication

Feugère, Lauric

Abstract

It is well established that aquatic animals inform their neighbours of predation risk through chemical cues. In this thesis, I tested the hypothesis that stress propagation is a widespread mechanism also activated by abiotic stressors – such as those arising from climate change. Inter-individual stress propagation was explored at different organisational levels (molecular to phenotypic), using different abiotic stressors (heat and pH), aquatic species (crustaceans, worms, fishes), ontogenic stages (embryos and adults), and types of interactions (intra- vs. interspecific). The molecular and phenotypic responses were measured in individuals directly stressed by abiotic stressors and in receivers exposed to stress metabolites released by abiotically-stressed individuals. As expected, abiotic stressors induced stress responses in donors. Heat-stressed zebrafish (Danio rerio) increased their cortisol levels and showed cellular stress responses, resulting in developmental and behavioural impairments. Fitness-relevant behaviours were impaired in pH-stressed ragworms (Hediste diversicolor) and hermit crabs (Diogenes pugilator), whilst shore crabs (Carcinus maenas) were resilient to pH stress. All tested species showed stress propagation, as donors and/or receivers of stress metabolites. Intraspecific stress propagation was observed in pH-stressed marine ragworms (but not crustaceans) and heat-stressed zebrafish embryos, through the release of stress metabolites that impaired the behaviour of their conspecifics. Conditioned water from pH-stressed sea bream (Sparus aurata) altered the behaviour of marine ragworm, shore crabs, and hermit crabs, suggesting interspecific stress propagation. Chemicals released by stressed animals differed to that from control individuals. The effects of stress metabolites were disrupted by acidic pH and amplified by high temperatures. Multi-omics showed that abiotic stressors shifted the metabolism of zebrafish embryo donors, which released stress metabolites (such as lipids and sulphur-containing compounds), that altered lipid transport, keratan sulfate, immune, antioxidant, cholinergic, and signalling pathways in receivers. Altogether, the findings from this thesis support the hypothesis that stress propagation is a widespread phenomenon existing in marine and freshwater species from embryos to adult stages, and that can be induced by abiotic stressors. Such stress propagation may have far-reaching consequences for populations under climate change-induced abiotic stress.

Citation

Feugère, L. The language of abiotic stress in aquatic animals : molecular characterisation of stress metabolite-mediated stress communication. (Thesis). University of Hull. https://hull-repository.worktribe.com/output/4311814

• Thesis Type: Thesis
• Deposit Date: Jun 12, 2023
• Publicly Available Date: Jun 12, 2023
• Keywords: Marine sciences ; Biological sciences
• Public URL: https://hull-repository.worktribe.com/output/4311814
• Additional Information: Department of Biological and Marine Sciences; The University of Hull
• Award Date: Dec 1, 2022