Linking variation in species' traits to large-scale environmental gradients can lend insight into the evolutionary processes that have shaped functional diversity and future responses change. Here, we ask how heat cold tolerance vary as a function of latitude, elevation climate extremes, using an extensive global dataset ectotherm endotherm thermal limits, while accounting for methodological acclimation temperature, ramping rate duration exposure among studies. We show previously reported...

Global warming appears to favour smaller-bodied organisms, but whether larger species are also more vulnerable thermal extremes, as suggested for past mass-extinction events, is still an open question. Here, we tested interspecific differences in tolerance (heat and cold) of ectotherm organisms linked their body mass genome size (as a proxy cell size). Since the vulnerability larger, aquatic taxa has been attributed oxygen limitation hypothesis, assessed how modulate with contrasting...

Aerobic metabolism generates 15-20 times more energy (ATP) than anaerobic metabolism, which is crucial in maintaining budgets animals, fueling activity, growth and reproduction. For ectothermic water-breathers such as fishes, low dissolved oxygen may limit uptake hence aerobic metabolism. Here, we assess, within a phylogenetic context, how abiotic biotic drivers explain the variation hypoxia tolerance observed fishes. To do so, assembled database of tolerance, measured critical tensions...

Abstract Virtually all aspects of the biology ectotherms are size‐and temperature‐dependent. Aerobic metabolism is often proposed to explain such relationships, with oxygen limitation setting limits heat tolerance and constraining growth. However, experimental tests role in have yielded mixed results, suggesting that may be important only certain contexts on time scales but not others. Here, using thermal death curves, which incorporate intensity duration stress, we quantify ability survive...

For aquatic breathers, hypoxia and warming can act synergistically causing a mismatch between oxygen supply (reduced by hypoxia) demand (increased warming). The vulnerability of these species to such interactive effects may differ during ontogeny due differing gas exchange systems. This study examines respiratory responses temperature across four life-stages the intertidal porcelain crab Petrolisthes laevigatus. Eggs, megalopae, juveniles adults were exposed combinations temperatures from 6...

Abstract The body size of an animal is strongly coupled to key ecological traits such as fecundity, mortality and growth . Ectothermic animals mature at smaller sizes in warmer conditions under low oxygen availability (hypoxia). Whether these responses result from changes cell number (which together determine size) how cellular may help ectotherms cope with heat hypoxia poorly understood. theory optimal postulates that imposes constraints on delivery: Differences differences membrane...

Abstract Low dissolved oxygen (hypoxia) is recognized as a major threat to aquatic ecosystems worldwide. Because paramount for the energy metabolism of animals, understanding functional and genetic drivers whole-animal hypoxia tolerance critical predicting impacts hypoxia. In this study, we investigate molecular evolution key genes involved in detection response ray-finned fishes: prolyl hydroxylase domain (PHD)–hypoxia-inducible factor (HIF) oxygen-sensing system, also known EGLN...

There is a growing interest in the physiology underpinning heat tolerance of ectotherms and their responses to ongoing rise temperature. However, there no consensus about underlying physiological mechanisms. According "the maintain aerobic scope regulate oxygen supply" hypothesis, warming at different organizational levels contribute ability safeguard energy metabolism via pathways. At cellular level, decrease cell size increases capacity for uptake resources (e.g., food oxygen), but...

Responses to climate change are rooted in thermal physiology, and many studies have focussed on heat tolerance plasticity of tolerance. Latitudinal patterns commonly considered reflect latitudinal differences regimes, but direct tests few. Here we show that the extremes fluctuations habitat temperature explain variation freshwater marine fishes. Furthermore, found fish exhibit greater than their counterparts. This reflects that, compared fishes, fishes exposed fluctuations. Our findings...

Abstract Partial migration is a key adaptive strategy, increasingly observed across multiple taxa. To investigate partial and life-cycle diversity of Merluccius australis in northwestern Patagonia, we analysed isotopic (δ13C, δ18O) elemental (11B, 23Na, 24 Mg, 55Mn, 86Sr, 138Ba) compositions otoliths from juveniles, sub-adults, adults to identify nursery origins, habitats used, migratory behaviours cohorts (1990–2005). Influence early size upon was assessed by comparing back-calculated sizes...

The effects of tidal height (high and low), acclimation to laboratory conditions (days in captivity) oxygen level (hypoxia normoxia) were evaluated the consumption rate (OCR) ghost shrimp Neotrypaea uncinata. We hypothesis that N. uncinata reduces its OCR during low tide increases it high tide, regardless acclimation. Additionally, existence an endogenous rhythm was explored, we examined whether synchronized with tidal, diurnal semidiurnal cycles. Unexpectedly, OCRs observed at normoxia,...

Abstract Partial migration, where migrant and resident organisms coexist within the same population, has been found in many fishes. Although it seems obvious that different life cycles exploit habitats food webs differently, few assessments about trophic consequences of partial migration are available. To unveil part this complexity, we combined otolith chemistry with stable isotope analyses data for hind-casting Merluccius australis habitat use diet composition at age. By providing detailed...

Whole-organism metabolic rate is a key trait for understanding ectotherms’ responses to ongoing environmental change. It represents the interface through which organisms interact with their environment and therefore allows making predictions across various levels of biological organisation. While much variation in rates explained by body size temperature, considerable part this remains unexplained. Lack standard research practices, data sparsity insufficient coverage taxa limit our capacity...

The assessment of thermal tolerance holds significant importance in predicting the physiological responses ectotherms, particularly elucidating their capacity for evolutionary adaptation context global warming. Current approaches to assessing have limitations that can lead misleading results, especially with regard heritability limits. In this study, we examined twenty isogenic lines Drosophila melanogaster from DGRP panel characterize death time (TDT) curves, which account duration and...

Abstract Global warming appears to favour smaller-bodied organisms, but whether larger species are also more vulnerable thermal extremes, as suggested for past mass-extinction events, is still an open question. Here, we tested interspecific differences in tolerance (heat and cold) of ectotherm organisms linked their body mass genome size (as a proxy cell size). Since the vulnerability larger, aquatic taxa has been attributed oxygen limitation hypothesis, assessed how modulate with...