Integrative Organismal Biology最新文献

{"title":"Baseline Testosterone Levels Peak During the Inactive Period in Male Degus (<i>Octodon degus</i>).","authors":"Y Sato, T M S Garcia, J S Low, C M Bauer","doi":"10.1093/iob/obaf033","DOIUrl":"10.1093/iob/obaf033","url":null,"abstract":"<p><p>The steroid hormone testosterone is important for stimulating male reproductive processes including territory acquisition, mating displays, and spermatogenesis. When examining the relative effects of testosterone on reproductive processes, it is most reasonable to focus on peak baseline testosterone levels, especially for reproductive processes that may occur during specific times of day, such as mating and spermatogenesis. However, some studies have not found consistent positive relationships between circulating testosterone levels and reproductive variables. These nonsignificant relationships could be driven by methodology, as most studies in wild, free-living animals collect blood samples during an animals' active period, yet many species show peak baseline testosterone levels during their inactive period. This may be the case for the common degu (<i>Octodon degus</i>), as field and laboratory studies have exclusively sampled these diurnal rodents during their active period and have found little correlation between testosterone levels and reproductive success. In this study, we measured testosterone levels in captive male degus every 4 h across a 24-h cycle to test the hypothesis that male degus demonstrate diel variation in their baseline testosterone levels. We saw significant variation in male degu baseline testosterone levels over a 24-h period, and our prediction that baseline testosterone levels would be higher during nighttime (inactive period) timepoints compared to daytime (active period) timepoints was supported. However, nighttime baseline testosterone levels were still several magnitudes lower than testosterone levels after a gonadotropin-releasing hormone (GnRH) injection. While GnRH injections significantly increased circulating plasma testosterone levels during any daytime time period, we found no significant correlation between nighttime baseline testosterone levels and post-GnRH testosterone levels, which suggests GnRH-challenges during the daytime cannot be used to approximate or estimate nighttime baseline testosterone levels. These findings expand our knowledge surrounding testosterone dynamics and suggest that future studies should take into account the time of day when sampling testosterone and other hormone levels.</p>","PeriodicalId":13666,"journal":{"name":"Integrative Organismal Biology","volume":"7 1","pages":"obaf033"},"PeriodicalIF":2.0,"publicationDate":"2025-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12342971/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144834987","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Testing for Differences in Metabolism Among Females and Dimorphic Males of Four Dung Beetle Species (Coloeoptera: Scarabaeinae).","authors":"A T Killeffer, J M Fleming, A Padukone, N Duerr, K A Reed, J Merizalde-Toro, K E Marshall, J E Celi, K S Sheldon","doi":"10.1093/iob/obaf031","DOIUrl":"10.1093/iob/obaf031","url":null,"abstract":"<p><p>Both sexual and male dimorphism are common in nature, yet we have limited understanding of how different developmental pathways and reproductive strategies of morphs shape energetics. To address this gap, we examined metabolic rates of four species of dung beetle (<i>Onthophagus taurus, Onthophagus hecate, Oxysternon silenus</i>, and <i>Phanaeus vindex</i>) with both sexual and male dimorphism. In these species, males have horn length dimorphism, including larger-horned (\"major\") males and smaller-horned (\"minor\") males. The gene doublesex, <i>dsx</i>, drives both sexual dimorphism and, by mediating nutrition-dependent horn growth in some species, male dimorphism. Because females and minor males share developmental pathways and have greater investment in reproductive organs than major males, we hypothesized energetic costs would be similar and higher in females and minor males compared to major males. To test this hypothesis, we examined metabolic rates of morphs using flow-through respirometry to record CO₂ output. After accounting for body size and activity level, we found that in two species, <i>Onthophagus taurus</i> and <i>Phanaeus vindex</i>, females had higher CO₂ production compared to major males, and in <i>O. taurus</i>, females also had higher CO₂ production than minor males. We detected no differences between sexes for <i>O. hecate</i> and <i>O. silenus</i>. We also found no significant difference in metabolic rates between major and minor males of any species. Our results suggest that, for these species of dung beetles, any energetic tradeoffs due to reproductive strategies occur between females and males, but not between male morphs. The lack of a general trend in metabolic rates suggests energetic costs are decoupled from sex and male morph across dung beetle species, which runs counter to evolutionary explanations for the maintenance of alternative reproductive tactics.</p>","PeriodicalId":13666,"journal":{"name":"Integrative Organismal Biology","volume":"7 1","pages":"obaf031"},"PeriodicalIF":1.9,"publicationDate":"2025-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12392089/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144952908","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Regeneration and Musculature in Halved <i>Cassiopea xamachana</i> Ephyrae.","authors":"K M Muffett, M Mammone, J Puckett, G Martino, Aditi, M P Miglietta","doi":"10.1093/iob/obaf030","DOIUrl":"10.1093/iob/obaf030","url":null,"abstract":"<p><p>Adult <i>Cassiopea</i> medusae and their polyps have been known to regenerate tissue in uncontrolled and controlled conditions; however, the regeneration capabilities of <i>Cassiopea xamachana</i> ephyrae are largely unexplored. Here, we detail the development and regeneration of ephyrae under known laboratory conditions. Ephyrae were cut in two and then followed as they regenerated back to complete individuals. We visually document all the developmental stages of the medusa leading up to the trauma and the complete regeneration process of the two halves. We show how ephyrae of <i>C. xamachana</i>, when cut in halves, undergo both regeneration and re-symmetrization, generating, in about 2 weeks, two functional smaller ephyrae with fewer rhopalia and normal behavior. We also show that regeneration is slower in older ephyra.</p>","PeriodicalId":13666,"journal":{"name":"Integrative Organismal Biology","volume":"7 1","pages":"obaf030"},"PeriodicalIF":1.9,"publicationDate":"2025-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12344487/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144845883","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Twist and Snout: Head and Body Morphologies Determine Feeding Kinematics in Substrate-Biting Fishes.","authors":"Tal Perevolotsky, Jacob M Brotman-Krass, Yarden Ratner, Yael Avigad, Adam P Summers, Cassandra M Donatelli, Roi Holzman","doi":"10.1093/iob/obaf032","DOIUrl":"10.1093/iob/obaf032","url":null,"abstract":"<p><p>Across teleosts, feeding by biting substrate-attached prey has evolved multiple times and is associated with convergent morphologies that include a deep body and an elongated, tapered head. However, the functional role of these morphologies in substrate-biting fish is not established. Here, we tested the hypothesis that these morphologies function as control surfaces that affect feeding kinematics during biting. To test this hypothesis, we used simplified physical models of substrate-biting reef fish and examined the role of head, body, and fin morphology in determining feeding kinematics that facilitate the removal of substrate-attached prey. Models simulated the swift lateral movement of the head, previously documented in species biting substrate-attached algae. Using models that capture the natural morphological variation of biters, we tested (i) how different head morphologies affect the speed of the head and (ii) how different body morphologies affect the stability of the body during head movements. We found that the moment of inertia (MOI) of the head and body explained most of the variation in head speed and body displacement. A decrease in head MOI resulted in faster lateral head movements, known to facilitate removal of attached prey. An increase in body MOI, relative to that of the head, stabilized the lateral displacement of the body during bites. Overall, our results suggest that the laterally compressed bodies and tapered snouts function as control surfaces during feeding in substrate-biting fish. We propose that a selective pressure to extend the lateral surface area underlies the prevailing morphological convergence of biting reef fishes.</p>","PeriodicalId":13666,"journal":{"name":"Integrative Organismal Biology","volume":"7 1","pages":"obaf032"},"PeriodicalIF":1.9,"publicationDate":"2025-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12392097/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144952979","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Toward a Comprehensive Anatomical Matrix for Crown Birds: Phylogenetic Insights from the Pectoral Girdle and Forelimb Skeleton.","authors":"A Chen, E M Steell, R B J Benson, D J Field","doi":"10.1093/iob/obaf029","DOIUrl":"10.1093/iob/obaf029","url":null,"abstract":"<p><p>Phylogenetic analyses of phenotypic characters in crown-group birds often recover results that are strongly incongruous with the findings of recent phylogenomic analyses. Furthermore, existing morphological datasets for crown birds are frequently limited by restricted taxon or character sampling, inconsistent character construction, incorrect scoring, or a combination of several of these factors. As part of an effort to address these limitations, in this study we focus on identifying phylogenetically informative characters of the avian pectoral girdle and forelimb skeleton, elements of which are commonly preserved as avian fossils. We assembled and vetted a dataset of 203 characters, which were then scored for a phylogenetically diverse range of 75 extant avian taxa and incorporated into phylogenetic analyses. Analyses run without topological constraints exhibited notable conflicts with the results of recent phylogenomic studies, possibly due to functional convergence and rapid cladogenesis in the early evolutionary history of crown birds. Qualitative anatomical comparisons and quantitative metrics of homoplasy further highlighted the fact that similar morphologies in pectoral girdle and forelimb elements have evolved repeatedly in distantly related groups of birds, representing a major confounding factor in avian morphological phylogenetics. However, the implementation of molecular scaffolds allowed the identification of diagnostic character combinations for numerous avian clades previously only recognized through molecular data, such as Phaethontimorphae, Aequornithes, and Telluraves. Although large morphological datasets may not guarantee increased congruence with molecular phylogenetic studies, they can nonetheless be valuable tools for identifying anatomical synapomorphies of key clades, placing fossils into phylogenetic context, and studying macroevolutionary patterns within major groups of organisms.</p>","PeriodicalId":13666,"journal":{"name":"Integrative Organismal Biology","volume":"7 1","pages":"obaf029"},"PeriodicalIF":1.9,"publicationDate":"2025-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12409627/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145015202","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Camouflage, conspicuousness, and inducible color change in a polymorphic, sexually dichromatic frog.","authors":"R C Bell, C Irian, P J McLaughlin, K N Thomas, E R Loew, K R Zamudio","doi":"10.1093/iob/obaf028","DOIUrl":"10.1093/iob/obaf028","url":null,"abstract":"<p><p>Sexual dichromatism is prevalent throughout the animal tree of life and can play an important role in visual signaling and mate choice in many species. Some instances of sexual dichromatism, however, result from a combination of mechanisms including sexual niche partitioning and intrasexual signaling to identify competitors. Sexual dichromatism is relatively rare in anuran amphibians (frogs and toads) but is striking and prevalent in the African reed frogs (Hyperoliidae). In sexually dichromatic hyperoliids, males and females exhibit shared coloration post-metamorphosis, but at the onset of maturity, females undergo a change in color and/or color pattern whereas males typically retain the juvenile coloration. Hypothesized functions of dichromatism in reed frogs include sexual niche partitioning such that males and females use different habitats and their different colorations provide more effective camouflage in their respective habitats or alternatively, that color patterns play a role in sex and/or mate recognition in dense breeding choruses. To test these hypotheses, we characterized several aspects of natural history, ecology, and physiology in a population of the sexually dichromatic forest reed frog (<i>Hyperolius tuberculatus</i>) on Bioko Island, Equatorial Guinea. We found that frogs were predominantly observed on green foliage regardless of coloration or sex, providing no support for sex and/or morph differences in habitat use. In addition, our visual modeling analyses demonstrated that both color morphs are likely detectable for typical vertebrate predators in bright light regardless of background foliage coloration. Analyses using a custom reed frog dual-rod photoreceptor visual model do not support the hypothesis that <i>H. tuberculatus</i> perceive chromatic (hue) differences between conspecific color morphs in dim light conditions, but instead suggest that both color morphs may be more conspicuous to conspecifics than to potential predators in dim light conditions. Finally, we documented multiple instances of mature males exhibiting female coloration and our preliminary steroid hormone exposure experiments indicate that exposure to estradiol induces a color change in adult male <i>H. tuberculatus</i>, as demonstrated in other members of the <i>Hyperolius viridiflavus</i> species complex. Collectively, our results demonstrate that the population of <i>H. tuberculatus</i> on Bioko Island is an excellent system for future studies investigating the behavioral, physiological, and molecular mechanisms underlying sexual dichromatism in reed frogs. Furthermore, the foundational data we present set the stage to characterize species discrimination and mate choice among sympatric and closely related species of reed frogs to investigate the roles of intra- or inter-specific female signaling in the evolution of dichromatism.</p>","PeriodicalId":13666,"journal":{"name":"Integrative Organismal Biology","volume":"7 1","pages":"obaf028"},"PeriodicalIF":2.0,"publicationDate":"2025-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12344550/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144855172","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Vision for VenomsBase: An Integrated Knowledgebase for the Study of Venoms and Their Applications.","authors":"T A Castoe, M Daly, F Jungo, K N Kirchhoff, I Koludarov, S Mackessy, J Macrander, S Mehr, M V Modica, E E Sanchez, G Zancolli, M Holford","doi":"10.1093/iob/obaf026","DOIUrl":"10.1093/iob/obaf026","url":null,"abstract":"<p><p>Venoms are complex bioactive mixtures that have independently evolved across diverse animal lineages, including snails, insects, sea anemones, spiders, scorpions, and snakes. Despite the growing interest in venom research, data is fragmented across disparate databases which lack standardization and interoperability. A vision for the proposed VenomsBase platform presented here seeks to address these challenges by using the best practices approach in creating a centralized, open-access platform adhering to FAIR principles (Findable, Accessible, Interoperable, and Reproducible). VenomsBase will unify venom datasets, standardize terminology, and enable comparative analyses across species, facilitating novel toxin discovery and functional annotation. Key features of VenomsBase include user-friendly data submission modules with built-in validation, advanced cross-species analysis tools, and integration of multidisciplinary datasets spanning genomics, transcriptomics, proteomics, functional assays, and ecological metadata. A modular, cloud-based design will ensure scalability, while heuristic scoring systems will guide users toward high-confidence data entries. To promote accessibility, the envisioned VenomsBase will provide tutorials, regular training sessions, case studies, and feedback loops, supporting researchers at all levels. By harmonizing venom research and addressing the limitations of outdated or nonstandardized methods, VenomsBase aims to revolutionize the field, while being continuously improved and refined by venom experts. This initiative will unlock venoms' potential to make groundbreaking discoveries, address global health challenges, and foster collaboration and innovation across the scientific community.</p>","PeriodicalId":13666,"journal":{"name":"Integrative Organismal Biology","volume":"7 1","pages":"obaf026"},"PeriodicalIF":1.9,"publicationDate":"2025-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12259279/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144636948","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impacts of Endogenous Factors and Ontogenetic Stages on the Metabolic Rate of the Mediterranean Spider Crab <i>Maja squinado</i> (Herbst, 1788).","authors":"M-C Raffalli, J-J Filippi, J Bracconi, N Gattacceca, J-B Ronchi-Perfetti, A Crescioni, J-H Lignot, E D H Durieux","doi":"10.1093/iob/obaf027","DOIUrl":"10.1093/iob/obaf027","url":null,"abstract":"<p><p>In the Mediterranean, populations of the spider crab <i>Maja squinado</i> are drastically declining. As a critical step toward restoration efforts, this study investigates ontogenetic metabolic changes from larvae to adults, accounting for size, molt stage, and sex. Routine metabolic rates were measured in reared larvae and juveniles, and wild-caught adults. Zoea 1, the first planktonic stage, showed higher metabolic rates than zoea 2, likely due to a greater proportion of metabolically inactive tissue and differing energy sources (egg reserves vs. exogenous feeding). From megalopa to benthic juvenile stages, metabolic rates increased exponentially, probably reflecting increased organ complexity and activity. However, rates declined significantly from 7-month-old juveniles to adults, potentially due to reduced growth, longer intermolt periods, and behavioral adaptations. Among adults, males exhibited metabolic rates twice as high as females, likely linked to greater territorial and reproductive activity. In 7-month-old juveniles at 14°C, mass-specific metabolic rate is inversely correlated with body size: individuals <20 g consumed oxygen at twice the mass-specific rate of those >80 g. The log₁₀ of oxygen consumption positively correlated with log₁₀ wet mass, with a \"b\" factor of 0.83. Molting also drastically influences metabolic activity, with lower rates observed in postmolt individuals than in individuals in premolt stages. The successful rearing of <i>M. squinado</i> and the significant physiological insights gained into the different developmental stages enhance our understanding of the species' biological processes, and pave the way for further analyses before the implementation of restoration trials.</p>","PeriodicalId":13666,"journal":{"name":"Integrative Organismal Biology","volume":"7 1","pages":"obaf027"},"PeriodicalIF":1.9,"publicationDate":"2025-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12280276/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144690110","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Within and Between-Leg Oil Transfer in an Oil Bee.","authors":"J Homburger, M Pineirua, J Casas, T Speck, F Gallenmüller","doi":"10.1093/iob/obaf025","DOIUrl":"10.1093/iob/obaf025","url":null,"abstract":"<p><p>Oil bees, which gather oil from flowers, transfer the floral oil collected from fore-legs, to middle-legs, and then to hind-legs, where they store the oil until release in the nest's brood cell. The complex leg maneuvers and the specialized hair types according to their location and function on the legs have been described in the past using morphological observations and <i>in vivo</i> behavioral monitoring, sometimes during flight. The aim of this work is to describe the different steps of oil transfer and to infer the role of the different hair types using a manipulative approach on isolated legs, controlled amounts of oil and high speed video recordings. A rapid and uni-directional capillary oil movement from the collecting ventral side of tarsi and/or tibiae to their dorsal side is observed in each fore-, middle-, and hind-legs. This suggests that plumose setae and pluridentate setae present different functionalities, acting either as oil donors or receptors, depending on their location on the legs. In the transfers observed, very little oil remains on the donor surface, so that a bee collecting oil from flower can quickly replenish the donor surface again.</p>","PeriodicalId":13666,"journal":{"name":"Integrative Organismal Biology","volume":"7 1","pages":"obaf025"},"PeriodicalIF":1.9,"publicationDate":"2025-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12215659/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144553458","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Heat-Induced Hatching: Clarifying Effects of Hydration and Heating Rate on Behavioral Thermal Tolerance of Red-Eyed Treefrog Embryos.","authors":"Estefany Caroline Guevara-Molina, Fernando Ribeiro Gomes, Karen M Warkentin","doi":"10.1093/iob/obaf023","DOIUrl":"10.1093/iob/obaf023","url":null,"abstract":"<p><p>Anurans are one of the most diverse groups of vertebrates but also most threatened by current climate change effects such as increasing environmental temperatures and more frequent and prolonged periods without rain. Many tropical anurans lay terrestrial eggs that are particularly vulnerable to drying and warming. In some such species, embryos hatch prematurely to escape from drying eggs. In red-eyed treefrogs, <i>Agalychnis callidryas</i>, embryos hatch early to escape both drying and excessive warming, expressing a behavioral thermal tolerance (i.e., VT_Max). Prior research suggested that drying reduces the VT_Max of embryos. However, because hydrated clutches warmed more slowly, the effect of drying on VT_Max was confounded with that of faster warming. To disentangle these dynamics, we designed a novel apparatus to warm terrestrial frog egg-clutches at controlled rates and minimize evaporative cooling. We independently manipulated clutch hydration and heat input to assess their individual and combined effects on embryo VT_Max. Proportional egg-volume loss was similar across hydration × heat input categories. High heat input resulted in higher clutch warming rates and shorter trial durations, across hydration levels. Within clutches, warming rates differed between back and surface thermocouple positions, generating thermal gradients as warming progressed. Clutch dehydration reduced embryo VT_Max, with no main or interacting effect of heat input. This evidence that egg drying reduces thermal tolerance across testing conditions supports a direct role for hydration in the behavioral decisions of warming embryos, rather than an indirect effect mediated by changes in evaporative cooling. It suggests that embryos assessing risk integrate information about hydration, and perhaps changes in hydration, with information about current and changing temperature. These findings highlight the value of methods to independently manipulate hydration and heating rate, showing the complexity of thermal ecology in embryonic ectotherms. We encourage further research on temperature and hydration effects on embryo hatching to better understand tropical anurans' adaptive strategies under climate change.</p>","PeriodicalId":13666,"journal":{"name":"Integrative Organismal Biology","volume":"7 1","pages":"obaf023"},"PeriodicalIF":1.9,"publicationDate":"2025-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12257936/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144636949","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}