Unexpected hormonal and behavioral responses to anthropogenic stressors in young common toads

Frontiers in Amphibian and Reptile Science, Journal Year: 2025, Volume and Issue: 3

Published: March 10, 2025

Introduction Anthropogenic conversion of natural habitats is one the most significant threats to biodiversity, and it also partially responsible for largest recorded decline in amphibians. Urbanization exposes wildlife increased disturbance by proximity humans, artificial light at night (ALAN), noise pollution, all which can be harmful wild animals. Glucocorticoid hormones may play an important role coping with environmental challenges. A growing body evidence indicates various vertebrate species that more efficient regulation glucocorticoid stress response favored selection under stressful conditions. In several species, baseline levels glucocorticoids their acute stressors are repeatable, heritable, related individual fitness. However, these latter respects, our knowledge scarce other aspects flexibility, such as ability recover from negative feedback. Methods To address this gap, we measured repeatability four corticosterone (CORT) profile (baseline release rate, strength agitation, rate recovery feedback, a recently proposed measure sequential variability) over ontogeny tadpoles juveniles common toad ( Bufo bufo ). Thereafter toadlets’ behavioral responses three anthropogenic stressors, specifically hop performance while fleeing human, foraging ALAN during daytime test whether hormonal characteristics explain differences between individuals. Results We found CORT changed ontogeny, its had low repeatability. Foraging both noise, two were correlated within individuals, but not performance. None variables variables. Discussion Our results suggest widespread environments, has limited consistency tolerance early development, pointing importance phenotypic plasticity challenges urban environments.

Language: Английский

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Validating the underpinnings of water corticosterone measurement for aquatic amphibians

F1000Research, Journal Year: 2025, Volume and Issue: 14, P. 53 - 53

Published: Jan. 9, 2025

Good animal welfare is important ethically but also to ensure animals provide valid scientific models. Despite thousands of amphibians in research laboratories there minimal quantitative evidence pertaining their management and welfare. This study validated methods non-invasively measure corticosterone, the amphibian 'stress' hormone, from tank water a robust reliable assessment tool. We report experiments (A) that evaluate parameters linked performance our biochemical extraction for waterborne corticosterone and, importantly, associated sampling procedures. appropriate type, vessel, filtration methods, potential degradation over time impact procedures on levels. wanted determine yielded least background had minimum negative animals. The second series (B) evaluated biology Xenopus, including influence circadian rhythm, sex snout-vent length levels, since fundamental knowledge species' essential designing interpretation results. propose collecting samples deionised either plastic or glass containers. filtering process does not amount measured sample. Levels collected change 48-hr period so we advocate standardising hormone collection storage at - 20 °C. Repeated transfer frogs containers increase suggesting are cumulatively stressful. Corticosterone levels were impacted by phase, length. have developed quantify corticosterone. hope they template researchers wishing develop aquatic amphibians.

Language: Английский

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Validation of non-invasive methods for the measurement of gonadal and inter-renal steroid hormones in a desert-adapted amphibian (Scaphiopus couchii)

Conservation Physiology, Journal Year: 2025, Volume and Issue: 13(1)

Published: Jan. 1, 2025

For aquatic and semi-aquatic vertebrates like amphibians, it is possible to estimate excreted hormone levels using non-invasive methods such as waterborne salivary sampling. These techniques allow monitoring of endocrine activity over varying, repeated simultaneous integration periods while minimizing handling-related stress that can 'contaminate' estimates, including estimates baseline glucocorticoids. Here we have validated the extraction quantification three steroid hormones (corticosterone, CORT; 17-b estradiol, E2; testosterone, TST) in Couch's spadefoots (Scaphiopus couchii)-a desert-adapted anuran special interest for physiology, evolution conservation-using minimally invasive methods. We combined enzyme immunoassay conduct conventional technical validations parallelism, recovery time-course. Next, carried out biological by testing correlation between circulating concentrations conducting pharmacological challenges. found all be precisely estimated from 60-min water baths, exhibit robust high recoveries. Further, demonstrated secretory responses challenges detected CORT male female frogs; TST E2 frogs, but not consistently or frogs. Lastly, plasma were correlated with their complements (both sexes), well males (but females). Plasma was also positively CORT. Together, our findings suggest sampling offers a method field endocrinologists conservation physiologists use obtain biologically informative amphibians.

Language: Английский

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Developmental temperature modulates microplastics impact on amphibian life history without affecting ontogenetic microplastic transfer

Journal of Hazardous Materials, Journal Year: 2024, Volume and Issue: 477, P. 135325 - 135325

Published: July 28, 2024

This study examines how temperature influences the response of Japanese tree frogs (Dryophytes japonicus) to microplastic (MP) pollution, assessing whether can regulate harmful effects MPs on their life history and dispersal across habitats. analysis aims understand ecological physiological ramifications MP pollution. Our results demonstrated an ontogenetic transfer particles amphibian metamorphosis, possibly allowing facilitating translocation ecosystems. Temperature did not significantly affect aquatic land. However, high temperatures reduced mortality hindlimb deformities caused by MPs, thereby mitigating impact histories. Importantly, our found that cause during potentially linked oxidative stress. Additionally, exposure ingestion induced a plastic in morphology digestive tract changes fecal microbiome, which were evident at but low temperatures. The persisted even after transitioned terrestrial stage, suggesting may have complex, long-term impacts population sustainability. enhance understanding intricate environmental challenges posed underscore significant role ectotherms regarding pollutant interactions.

Language: Английский

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Why not both? A case study measuring cortisol and corticosterone in poison frogs

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2023, Volume and Issue: unknown

Published: June 22, 2023

Abstract A general tenet in stress physiology is that the hypothalamic-pituitary-adrenal (HPA) axis predominantly produces one glucocorticoid (GC) response to stressors. However, two main glucocorticoids produced by vertebrates – cortisol and corticosterone show variation across species absolute levels, relative proportions, responsivity. Therefore, focusing on a single GC may not tell whole story. In this study, we measured both water samples collected from five of Dendrobatid poison frogs. Understanding full picture physiological frogs special interest due their susceptibility environmental stressors conservation status. Based pioneering studies steroidogenesis select few amphibians, thought be dominant more abundant all amphibians. Counter idea, found water-borne was than three species. Dendrobates tinctorius Phyllobates terribilis released equal amounts corticosterone. When stimulated HPA D. , responsive adrenocorticotropic hormone (ACTH), while did change. Comparing plasma samples, positively correlated with relationship between positive but statistically significant. These results challenge broadly accepted assumption ‘dominant’ amphibians add growing literature highlighting importance measuring GCs understand (stress) physiology.

Language: Английский

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Microbiome at the Interface between Environmental Stress and Animal Health: An Example from the Most Threatened Vertebrate Group

Published: Jan. 1, 2024

Nitrate pollution and increased temperatures due to climate change are ubiquitous stressors likely interact affect the health survival of wildlife, particularly aquatic ectotherms. Commensal/symbiotic microorganisms (microbiome) that inhabit animal bodies may contribute maintenance their under such stressful circumstances. We conducted a common-garden experiment crossing three nitrate levels (0, 50, 100 mg/L) five temperature treatments (18 °C, 22 26 28 fluctuation regime: 17–26.5 °C) investigate interactive individual effects these on biomarkers (water-borne corticosterone, body condition, developmental rate) an ectotherm its gut microbiome diversity composition, using amphibian larvae as model organisms. All reflected thermal stress imposed larvae, outcomes being more explained by changes in composition than diversity. Based detected OTUs, we predicted increase reduction pathway decrease several nucleotide biosynthesis pathways with increasing pollution, alterations degradation temperature. urge for studies investigating different environmental conditions consequences host world threatened biodiversity loss.

Language: Английский

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The microbiome at the interface between environmental stress and animal health: an example from the most threatened vertebrate group

Proceedings of the Royal Society B Biological Sciences, Journal Year: 2024, Volume and Issue: 291(2031)

Published: Sept. 1, 2024

Nitrate pollution and global warming are ubiquitous stressors likely to interact affect the health survival of wildlife, particularly aquatic ectotherms. Animal is largely influenced by its microbiome (commensal/symbiotic microorganisms), which responds such stressors. We used a crossed experimental design including three nitrate levels five temperature regimes investigate their interactive individual effects on an ectotherm, European common frog. associated biomarkers in larvae with changes gut bacteria diversity composition. Larvae experienced higher stress lower body condition under high temperatures exposure. Developmental rate increased but decreased pollution. Alterations composition not correlate observed outcomes health. Leucine degradation at corroborating accelerated development, level reduced increase lysine biosynthesis may have helped deal combined both These results reinforce importance associating traditional underlying changes. Therefore, we urge studies environmental consequences for host world threatened biodiversity loss.

Language: Английский

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Physiological responses to a changing winter climate in an early spring-breeding amphibian

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: Jan. 4, 2024

Climate change is swiftly altering environmental winter conditions, leading to significant ecological impacts such as phenological shifts in many species. As a result, animals might face physiological mismatches due longer or earlier activity periods and are at risk of being exposed late spring freezes. Our study points for the first time complex challenges that amphibians result changing thermal conditions climate change. We investigated responses period warmer days sudden freeze common toad ( Bufo bufo ) by acclimating them 4°C 8°C 48 h exposing -2°C 6 h, respectively. assessed daily energy demands, determined body condition cold tolerance, explored molecular freezing through hepatic tissue transcriptome analysis, measured blood glucose levels. Toads acclimated higher temperatures showed expenditure reduced tolerance suggesting faster depletion stores loss acclimation during winters. Blood sugar levels were frozen toads indicating mobilization cryoprotective with which was further supported changed patterns proteins related metabolism. Overall, our results emphasize increased variability incurs costs may reduce reserves thus affect amphibian health survival. This pose serious threat breeding adults have subsequent effects population level.

Language: Английский

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The role of phenotypic plasticity and corticosterone in coping with pond drying conditions in yellow‐bellied toad (Bombina variegata, Linnaeus 1758) tadpoles

Journal of Experimental Zoology Part A Ecological and Integrative Physiology, Journal Year: 2024, Volume and Issue: 341(7), P. 753 - 765

Published: April 23, 2024

Amphibian larvae inhabiting temporary ponds often exhibit the capacity to accelerate development and undergo metamorphosis in challenging conditions like desiccation. However, not all species this ability, yellow-bellied toad (Bombina variegata) is one such example. The underlying mechanisms behind inability under desiccation remain largely unexplored. hypothalamic-pituitary-interrenal (HPI) axis corticosterone (CORT), which act synergistically with thyroid hormone, are thought facilitate response stress. In study, we aimed investigate whether modification HPI axis, particularly CORT levels, contributes absence of adaptive plasticity B. variegata study design included four treatments: high water level, level exogenous CORT, low metyrapone (a synthesis inhibitor). main objective was evaluate effects these treatments on whole-body life history, morphological traits, oxidative stress parameters during prometamorphic metamorphic climax developmental stages. While had no effect total larval period, body condition index, shape, it negatively affected metamorph size, mass, growth rate. Our findings suggest that constant exposure over generations may have led modifications activity variegata, resulting adaptation changes evident through response. Consequently, be a relevant indicator for species.

Language: Английский

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Physiological responses to a changing winter climate in an early spring‐breeding amphibian

Ecology and Evolution, Journal Year: 2024, Volume and Issue: 14(7)

Published: July 1, 2024

Abstract Climate change is swiftly altering environmental winter conditions, leading to significant ecological impacts such as phenological shifts in many species. As a result, animals might face physiological mismatches due longer or earlier activity periods and are at risk of being exposed late spring freezes. Our study points for the first time complex challenges that amphibians result changing thermal conditions climate change. We investigated responses period warmer days sudden freeze common toad ( Bufo bufo ) by acclimating them 4°C 8°C 48 h exposing −2°C 6 h, respectively. assessed daily energy demands, determined body condition cold tolerance, explored molecular freezing through hepatic tissue transcriptome analysis, measured blood glucose levels. Toads acclimated higher temperatures showed expenditure reduced tolerance suggesting faster depletion stores loss acclimation during winters. Blood sugar levels were frozen toads indicating mobilization cryoprotective with which was further supported changed patterns proteins related metabolism. Overall, our results emphasize increased variability incurs costs may reduce reserves thus affect amphibian health survival. This pose serious threat breeding adults have subsequent effects population level.

Language: Английский

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