Biology subjects

Eterovick, P. C.

Publications and source records attributed to Eterovick, P. C..

3 recordsLinked to original sources

bioRxiv2026

Microbiome plasticity, not gut morphology, is linked to amphibian larval performance under elevated temperatures and low food quality

In many ecosystems, anthropogenic warming is reshaping thermal regimes, leading to resource quality declines and imposing a dual constraint for ectotherms: elevated metabolic demand coupled with reduced assimilable energy. We tested whether plasticity in gut morphology and gut microbiome can buffer amphibian larvae against these concurrent stressors. Common frog (Rana temporaria) tadpoles were reared at two temperatures (18 vs. 24.5{degrees}C) crossed with three food-quality treatments (low, medium, high). We quantified growth and developmental rates, critical thermal limits (CTmax, CTmin), gut morphology (mass, relative length), and gut bacterial diversity and composition, together with predicted functional pathways. Warming accelerated growth and development and increased CTmax. Food quality increased growth and development, with temperature-dependent effects on developmental rate and CTmax. Gut mass declined at higher temperature and low-quality diets, but relative gut length showed only modest diet effects and no temperature dependence. Bacterial community composition and structure shifted with temperature and food quality. Predicted pathways suggest functional reconfiguration under warming and low food quality, consistent with sustaining energy acquisition and mitigating metabolic and oxidative stress. Together, these results implicate microbiome plasticity, rather than gut morphological plasticity, as a candidate mechanism supporting larval performance and heat-tolerance acclimation under warming and low food quality.

ecology↗

bioRxiv2024

Living in a multi-stressor world: nitrate pollution and thermal stress interact to affect amphibian larvae

The interaction of widespread stressors such as nitrate pollution and increasing temperatures associated with climate change are likely to affect aquatic ectotherms such as amphibians. The metamorphic and physiological traits of amphibian larvae during the critical onset of metamorphosis are particularly susceptible to these stressors. We conducted a common-garden experiment using Rana temporaria larvae subjected to four constant acclimation temperatures (18, 22, 26, 28 {degrees}C) crossed with three environmentally relevant nitrate concentrations (0, 50, 100 mg x L-1) to investigate the interactive and individual effects of these stressors on metamorphic (i.e., growth and development) and physiological traits (i.e., metabolism and heat tolerance) at the onset of metamorphosis. Larvae exposed to elevated nitrate concentrations and thermal stress displayed increased metabolic rates but decreased developmental rate, highlighting interactive effects of these stressors. However, nitrate pollution alone had no effect on either metamorphic or physiological traits, suggesting that detoxification processes were sufficient to maintain homeostasis but not in combination with increased acclimation temperatures. Furthermore, larvae exposed to nitrate displayed diminished abilities to exhibit temperature-induced plasticity in metamorphosis timing and heat tolerance, as well as reduced acclimation capacity in metabolic rate and heat tolerance to higher temperatures. These results highlight the importance of considering the exposure to multiple stressors when investigating how natural populations respond to global change.

ecology↗

bioRxiv2023

Acclimation Capacity to Global Warming of Amphibians and Freshwater Fishes: Drivers, Patterns, and Data Limitations

Amphibians and fishes play a central role in shaping the structure and function of freshwater environments. These organisms have a limited capacity to disperse across different habitats and the thermal buffer offered by freshwater systems is small. Understanding determinants and patterns of their physiological sensitivity across life history is, therefore, imperative to predicting the impacts of climate change in freshwater systems. Based on a systematic literature review including 345 experiments with 998 estimates on 96 amphibian (Anura/Caudata) and 93 freshwater fish species (Teleostei), we conducted a quantitative synthesis to explore phylogenetic, ontogenetic, and biogeographic (thermal adaptation) patterns in upper thermal tolerance (CTmax) and thermal acclimation capacity (Acclimation Response Ratio, ARR) as well as the influence of the methodology used to assess these thermal traits using a conditional inference tree analysis. We found globally consistent patterns in CTmax and ARR, with phylogeny (taxa/order), experimental methodology, climatic origin, and life stage as significant determinants of thermal traits. The analysis demonstrated that CTmax does not primarily depend on the climatic origin but on experimental acclimation temperature and duration, and life stage. Higher acclimation temperatures and longer acclimation times led to higher CTmax values, whereby Anuran larvae revealed a higher CTmax than older life stages. The ARR of freshwater fishes was more than twice that of amphibians. Differences in ARR between life stages were not significant. In addition to phylogenetic differences, we found that ARR also depended on acclimation duration, ramping rate, and adaptation to local temperature variability. However, the amount of data on early life stages is too small, methodologically inconsistent, and phylogenetically unbalanced to identify potential life cycle bottlenecks in thermal traits. We therefore propose methods to improve the robustness and comparability of CTmax/ARR data across species and life stages, which is crucial for the conservation of freshwater biodiversity under climate change.

ecology↗