Integrative Organismal Biology最新文献

{"title":"Sexually Different Parental Inputs in Pheasant-tailed Jacanas and the Correlates with Brood Success.","authors":"Y-M Kuo, Y-F Lee, B-Y Chuang, Y-J Kuo, H-C Hsu, Y-Y Chiang, Y-L Tai, S-L Chang, C-Y Lin, Y-J Huang, W-C Lee","doi":"10.1093/iob/obaf035","DOIUrl":"10.1093/iob/obaf035","url":null,"abstract":"<p><p>Parental care and territoriality are crucial components for the success of avian reproduction. Biparental care with female-biased efforts prevails in avian species, whereas breeding territories in most birds are male- or bisexual-defended. In social-polyandrous birds, however, females trade parental care for mating through sex-role reversal. On the other hand, managing multiple broods or mating events exposes females to physiological/environmental constraints of energetic-nutritional demands, which in turn may result in variations in egg mass and subsequent egg fates. This study assessed sexual differences in parental efforts, including territoriality, time allocation of parental behaviors, and egg-laying (reflected by egg mass) in sex-role-reversed pheasant-tailed jacanas, <i>Hydrophasianus chirurgus</i>, and their relationships with brood success. Females monopolized small ponds but shared larger ones with female neighbors by holding larger territories. In contrast, male territories were within those of their mates, the size was not affected by the presence of male neighbors, and was associated with the total hatchlings and fledglings obtained through multiple clutches. The time allocated in parental behaviors differed between the sexes and across the pre-laying, incubation, and post-hatching stages. The breeding duration, territory size, female breeding order, and male mating order, however, had no effects on parental time allocation. While male time spent chick-attending was positively correlated with brood success, preening negatively correlated with the fledging rate, other behaviors had no effects on reproductive outputs. The egg mass varied slightly, but showed no effect of year, nor the season of laying date until late August. The fourth egg in a clutch was lighter and, among clutches, the egg mass tended to be greater in later clutches and clutches from polyandrous females. We found positive correlations between mean egg mass and the numbers of hatchlings and fledglings gained per clutch. Our results suggest a substantial pre-laying parental input through egg production in polyandrous females. Brood success, however, appears to be determined by the combined effects of multiple factors, including male devotion and environmental conditions.</p>","PeriodicalId":13666,"journal":{"name":"Integrative Organismal Biology","volume":"7 1","pages":"obaf035"},"PeriodicalIF":1.9,"publicationDate":"2025-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12451437/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145130695","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":"Two Decapod Crustaceans, <i>Panopeus herbstii</i> and <i>Petrolisthes armatus</i>, Stabilize Their Gaze Using Achromatic Visual Cues, but Not the Angle of Linearly Polarized Light.","authors":"M Janakis, S Guirges, A C Grant, I Paris, E F LoPresti, D I Speiser","doi":"10.1093/iob/obaf034","DOIUrl":"10.1093/iob/obaf034","url":null,"abstract":"<p><p>Gaze stabilization is important to animals because it allows them to visually differentiate between their own motion relative to their environment and the motion of objects within their environment. Animals can struggle to stabilize their gaze in environments that have a high amount of visual noise. In shallow aquatic environments, such as tidal creeks, the motion of the water's surface can create dynamic spatiotemporal fluctuations in illumination referred to as \"caustic flicker.\" This type of visual noise can create false-motion cues. To overcome this obstacle, shallow-dwelling aquatic animals may use color or polarized cues to stabilize their gaze rather than achromatic cues. Tidal creeks are often spectrally narrow due to light absorption by suspended particles such as algae, making color vision unreliable. Instead of using achromatic or chromatic cues, we hypothesize that crabs in tidal creeks stabilize their gaze using cues that vary in their angle of linear polarization (AoLP). To ask whether crabs from tidal creeks may use AoLP cues in gaze stabilization, we investigated polarization sensitivity in the Atlantic mud crab, <i>Panopeus herbstii</i>, and the green porcelain crab, <i>Petrolisthes armatus</i>. Using optomotor behavioral assays, we found that both porcelain and mud crabs use achromatic cues for gaze stabilization, but neither use AoLP cues across a range of light conditions that varied in spectral width, spectral peak, and total irradiance. Our findings are further evidence that although animals may theoretically benefit from using AoLP cues for gaze stabilization in visually noisy aquatic habitats, decapod crustaceans from tidal creeks seem to rely on achromatic cues for this task.</p>","PeriodicalId":13666,"journal":{"name":"Integrative Organismal Biology","volume":"7 1","pages":"obaf034"},"PeriodicalIF":1.9,"publicationDate":"2025-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12395132/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144952904","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":"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":1.9,"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":1.9,"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}