Bethany L Williams, Lauren M Pintor, Jai Tiarks, Suzanne M Gray
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引用次数: 0
Abstract
Freshwater organisms face a complex array of environmental stressors that can negatively affect endocrine function and subsequent fitness outcomes. Hypoxia and turbidity are two environmental stressors that are increasing due to human activities that could lead to endocrine disruption and reduced reproductive output. Our research addresses how hypoxia and elevated turbidity affect traits related to reproductive success, specifically sex hormone concentrations, investment in reproductive tissues and body size. We used wild fish from two populations (a river and a swamp) of an African cichlid, Pseudocrenilabrus multicolor, to produce offspring that were reared in a full factorial split brood rearing experiment (hypoxic/normoxic × clear/turbid). River and swamp populations represent divergent habitat types with respect to the stressors of interest, being well-oxygenated but turbid or hypoxic and clear, respectively. Overall, we found evidence for plastic responses to both stressors. Specifically, we found that there was an interactive effect of oxygen and turbidity on testosterone in males from both populations. Additionally, males of both populations reared under hypoxic conditions were significantly smaller in both mass and standard length than those raised under normoxic conditions and invested less in reproductive tissues (quantified as gonadosomatic index). Hypoxia and turbidity are experienced naturally by this species, and these environmental stressors did not affect the number of eggs laid by females when experienced in the absence of another stressor (i.e. normoxic/turbid or hypoxic/clear). However, there was an interactive effect of hypoxia and turbidity, as females reared and maintained under this treatment combination laid fewer eggs. This research underscores the importance of considering the possibility of stressor interactions when determining how anthropogenic stressors affect fitness outcomes.
期刊介绍:
Conservation Physiology is an online only, fully open access journal published on behalf of the Society for Experimental Biology.
Biodiversity across the globe faces a growing number of threats associated with human activities. Conservation Physiology will publish research on all taxa (microbes, plants and animals) focused on understanding and predicting how organisms, populations, ecosystems and natural resources respond to environmental change and stressors. Physiology is considered in the broadest possible terms to include functional and mechanistic responses at all scales. We also welcome research towards developing and refining strategies to rebuild populations, restore ecosystems, inform conservation policy, and manage living resources. We define conservation physiology broadly and encourage potential authors to contact the editorial team if they have any questions regarding the remit of the journal.