Ecological and evolutionary physiology最新文献

{"title":"Hypoxia and Thermogenesis Constrain Peak V̇o₂ in Exercising Naked Mole Rats.","authors":"Sidney Abar, Maiah E M Deveraux, Vincent Careau, Matthew E Pamenter","doi":"10.1086/736423","DOIUrl":"10.1086/736423","url":null,"abstract":"<p><p>AbstractHypoxia-tolerant naked mole rats (NMRs) depress metabolic rate >85% in severe hypoxia and switch from mixed lipids/carbohydrates to total carbohydrate-fueled metabolism. Previous experiments have studied resting animals, but how exercising NMRs balance hypoxic hypometabolism with thermogenic and activity-related demands is unknown. Therefore, we explored how interactions between hypoxia and intense exercise impact metabolic rate (oxygen consumption rate [V̇o₂]), aerobic scope, and fuel usage in normoxia or hypoxia (7% O₂) and at 22°C or 30°C. We found that hypoxia had the largest impact on both V̇o₂ and peak V̇o₂ in either temperature and both in stationary-wheel conditions and during forced exercise (animals made to run at their maximum sustainable rate). In hypoxia, exercising V̇o₂ and peak V̇o₂ were not elevated from stationary-wheel conditions, indicating that hypoxia constrains the metabolic scope available for intense exercise. Conversely, metabolic rate was not impacted by temperature in hypoxia. Finally, hypoxia, but not exercise or experimental temperature, drove a shift in fuel use toward carbohydrate metabolism. Together, our findings indicate that environmental hypoxia is the primary determinant of metabolic fuel use and the key limiter of V̇o₂ in exercising NMRs. We conclude that hypoxic hypometabolism is prioritized over thermoregulatory and behavioral demands in this species. This relationship likely supports the ecophysiology of this species: NMR burrows are presumed to be warmest and most hypoxic in densely populated nests where animals tend to be sedentary but cooler and less hypoxic in distant burrow regions where animals undertake energetically intense tasks, such as tunnel expansion and foraging behaviors.</p>","PeriodicalId":519900,"journal":{"name":"Ecological and evolutionary physiology","volume":"98 3","pages":"196-206"},"PeriodicalIF":0.0,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144765978","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparison of Sample Extraction and Storage Methods across Time for Fecal Progesterone Metabolite Analysis in Female Verreaux's Sifaka.","authors":"Allison Hays, Madalena Birr, Mateo Peñaherrera-Aguirre, Erica Cook, Rebecca J Lewis, Stacey Tecot","doi":"10.1086/736425","DOIUrl":"https://doi.org/10.1086/736425","url":null,"abstract":"<p><p>AbstractResearchers commonly collect fecal samples from wild animals to monitor steroid metabolites and associate them with ecology and behavior. This method requires that we develop and validate species-specific methods that are appropriate for various field conditions and compatible with laboratory resources. We compared multiple extraction and storage methods for analyzing fecal progesterone metabolites (fPms) in wild female Verreaux's sifaka (<i>Propithecus verreauxi</i>). We created a subset of samples from a single homogenized fecal pool. We preserved samples by freezing, desiccation, and suspension on four different brands of solid-phase extraction (SPE) cartridges and extracted or eluted samples under each condition at 0-, 90-, 180-, and 270-d intervals for subsequent enzyme immunoassay. Mean progesterone metabolite levels varied across conditions (<math><mrow><mn>655.41</mn><mo>±</mo><mn>247.46</mn></mrow></math> to <math><mrow><mn>846.09</mn><mo>±</mo><mn>217.44</mn></mrow></math> ng/g). Frozen samples generally yielded the highest fPm levels; post hoc comparisons, with Bonferroni correction, indicated that samples that were desiccated and samples that were suspended on Alltech Maxi-Clean SPE cartridges were the most similar to frozen samples overall (<math><mrow><mi>P</mi><mo>></mo><mn>0.05</mn></mrow></math>). Alltech SPE cartridges produced the most consistent results within and across time points. We were unable to suspend or elute sample extracts using SPE cartridges from two brands that were not developed for long-term storage. Based on samples from the remaining four conditions, fPm levels did not vary from time point 1, except for an increase in time point 4 (<math><mrow><mi>β</mi><mo>=</mo><mn>0.050</mn></mrow></math>, <math><mrow><mi>SE</mi><mo>=</mo><mn>0.025</mn></mrow></math>, <math><mrow><mi>t</mi><mo>=</mo><mn>2.002</mn></mrow></math>, <math><mrow><mi>P</mi><mo>=</mo><mn>0.046</mn></mrow></math>), suggesting long-term stability to at least 180 d. However, no consistent trend across time was apparent within any condition. Overall, we found that freezing, desiccation, and field extraction using Alltech SPE cartridges are reliable methods for measuring fPms in <i>Propithecus edwardsi</i>. We provide guidance for choosing methods under certain field and laboratory conditions, as well as detailed protocols that can help guide protocol development for analyzing fecal steroid metabolites in other species.</p>","PeriodicalId":519900,"journal":{"name":"Ecological and evolutionary physiology","volume":"98 3","pages":"182-195"},"PeriodicalIF":0.0,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144765977","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Migration and Spawning Affect the Stable Isotope Values of Multiple Tissues in Pacific Salmon.","authors":"Kathryn S Peiman, David A Patterson, Scott G Hinch, Michael Power, Steven J Cooke","doi":"10.1086/736706","DOIUrl":"https://doi.org/10.1086/736706","url":null,"abstract":"<p><p>AbstractMigration can be energetically demanding for animals, especially when individuals have only one chance to reproduce and rely on stored energy to complete both tasks. We investigated whether protein and fat catabolism, measured by stable isotope values, predicted successful migration and reproduction in semelparous sockeye salmon (<i>Oncorhynchus nerka</i>) in the Fraser River, British Columbia. We used stable isotope values of carbon (δ¹³C) and nitrogen (δ¹⁵N) from adipose fins, blood, and scales sampled upon initial capture to assess an individual's oceanic habitat use; used passive integrated transponders to measure migration timing and success; and then collected isotope samples from the same individuals upon death to assess the level of protein and fat catabolism. We also assessed catabolism in pink salmon (<i>Oncorhynchus gorbuscha</i>) using stable isotope values from scales and adipose fins collected at death. We found consistent increases in δ¹³C over time across sockeye salmon tissues, showing that δ¹³C values collected from dead fish no longer represent ocean conditions. In contrast, δ¹⁵N increased only in adipose tissue of sockeye males and was particularly high in large male pink salmon, likely because of their extreme morphological changes for spawning. Migration time through lakes was related to δ¹³C, suggesting that males with lower energy reserves spent less time in lakes before spawning, and successful female sockeye spawners had higher δ¹³C values, suggesting that they catabolized more fat than unsuccessful females. Even though we were unable to link ocean habitat use to migration or reproductive success, we found several patterns of isotopic increases due to protein and lipid catabolism. These findings have implications for reinterpreting past and future studies using stable isotope values collected from migrating or dead salmon and, by extension, other animals.</p>","PeriodicalId":519900,"journal":{"name":"Ecological and evolutionary physiology","volume":"98 3","pages":"161-181"},"PeriodicalIF":0.0,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144765980","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Temporal Patterns, Behavioral Drivers, and Physiological Correlates of West Nile Virus Exposure in American Robins (<i>Turdus migratorius</i>).","authors":"Alex E Jahn, Kyle Koller, Lynn B Martin, Tara M Smiley, Taylor B Verrett, Ellen D Ketterson, Emily J Williams, Daniel J Becker","doi":"10.1086/736501","DOIUrl":"https://doi.org/10.1086/736501","url":null,"abstract":"<p><p>AbstractComplex interactions between animal migration and infection are increasingly recognized as important for shaping when and where wildlife are infectious. Bird migration may facilitate spatial spread of zoonotic pathogens but remains poorly understood, owing in part to limited seasonal sampling. Using serology for immunoglobulin Y antibodies, we evaluated seasonal exposure to West Nile virus (WNV) of American robins (<i>Turdus migratorius</i>) sampled monthly during 2021 and 2022 in Indiana and compared our seroprevalence results to those of robins from previous studies across North America using meta-analysis. Because robins overwintering in Indiana include local breeders and those breeding farther north, we next evaluated how the probability of WNV exposure varied by breeding latitude. We also tagged robins breeding in Indiana with tracking devices to evaluate whether exposure to WNV is related to movement distance. We found that robins in Indiana are exposed to WNV more frequently than robins in previous studies elsewhere in North America and in earlier years, but we found no effects of season, sex, or breeding latitude. However, robins with higher fat scores were more likely to be seropositive, which may indicate that these birds are more likely to survive infection. Our tracking data indicated that robins breeding in Indiana migrate several hundred miles to overwinter in the southeastern United States and that WNV seropositivity had no association with movement distance. The mean durations of spring and fall migration were 13 and 19 d, respectively, nearly the same as or moderately above the maximum WNV infectious period in robins. Although these results suggest that American robins have the capacity to move WNV long distances in spring, further studies are needed across the range of this host species to uncover its role in dispersing WNV.</p>","PeriodicalId":519900,"journal":{"name":"Ecological and evolutionary physiology","volume":"98 3","pages":"133-145"},"PeriodicalIF":0.0,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144765981","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Insensible Evaporative Water Loss Control by an Australian Arid-Habitat Psittacine, the Mulga Parrot (<i>Psephotellus varius</i>).","authors":"Christine Elizabeth Cooper, Philip Carew Withers, Marthe Monique Gagnon","doi":"10.1086/736561","DOIUrl":"https://doi.org/10.1086/736561","url":null,"abstract":"<p><p>AbstractFor terrestrial animals, evaporative water loss (EWL) is a crucial component of osmotic balance and thermoregulation. At high ambient temperatures, augmented EWL for thermoregulation is well recognized, but there is growing evidence that insensible EWL at temperatures within and below thermoneutrality is also regulated and does not just passively conform to Fick's Law. We investigated the capacity of the arid-habitat mulga parrot (<i>Psephotellus varius</i>) to physiologically regulate its insensible EWL within or below thermoneutrality (15°C-30°C) using open-flow respirometry and manipulating two physical parameters, the water vapor pressure deficit (by varying atmospheric relative humidity) and the water diffusion coefficient (using a helox atmosphere). Both experimental approaches provided evidence for physiological control of EWL. There was no significant effect of relative humidity on EWL despite the reduced water vapor pressure deficit at high relative humidity, and EWL did not increase in response to a higher vapor diffusion coefficient in helox despite expected increases in thermal conductance, metabolic rate, and ventilatory parameters. Adjustments of both respiratory and cutaneous EWL contributed to the control of EWL, achieved by modifying a combination of ventilatory parameters, expired air temperature, skin resistance, and, to a lesser extent, skin temperature. These results are important for understanding how animals function in, and respond to, their environment.</p>","PeriodicalId":519900,"journal":{"name":"Ecological and evolutionary physiology","volume":"98 3","pages":"146-160"},"PeriodicalIF":0.0,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144765979","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Diet-Induced Shifts in the Hindgut Microbiome Leads to Subtle Changes in Gut and Liver Function of a Marine Herbivorous Fish.","authors":"Michelle J Herrera, Joseph Heras, Caitlyn Catabay, Michelle Booth, Kwasi M Connor, Donovan P German","doi":"10.1086/736035","DOIUrl":"https://doi.org/10.1086/736035","url":null,"abstract":"<p><p>AbstractThe diet of an organism can influence various biological processes, including digestion. By examining how dietary changes can shift gut physiology in an herbivorous fish, we can gain insight into what that species can tolerate in terms of dietary shifts. Thus, we investigated how gut mass, digestive enzyme activity, hindgut microbial diversity, levels of gastrointestinal fermentation, and hindgut and liver transcriptomics respond to dietary perturbations in the marine herbivorous fish <i>Cebidichthys violaceus</i>. Contrary to our expectations, fish fed an omnivore diet (45% protein) in the laboratory exhibited the most similarity to wild-caught herbivorous fish, sharing a high abundance of taxa in the Bacteroidota and Bacillota phyla (families Ruminococcaceae and Rikenellaceae) and the highest concentrations of short-chain fatty acids. Fish in these groups shared similarities in gene expression patterns too. Fish fed herbivore (~23% protein) or carnivore (~69% protein) diets in the laboratory had a high abundance of taxa from the Pseudomonadota phylum (families Burkholderiaceae and Oxalobacteraceae) and lower short-chain fatty acid concentrations. The hindgut had 519 differentially expressed genes, with wild-caught fish exhibiting a high expression of genes associated with ion transport, lipid metabolism, and glucose metabolism. The liver had 4,650 differentially expressed genes, and wild-caught fish had a high expression of genes related to fatty acid synthesis and proteolysis. Hindgut digestive enzyme activities also varied with diet and microbial diversity. Our integrative study furthers our understanding of the physiology of an herbivorous fish and how it responds to shifting dietary resources, particularly with an eye toward herbivorous fish aquaculture.</p>","PeriodicalId":519900,"journal":{"name":"Ecological and evolutionary physiology","volume":"98 2","pages":"111-131"},"PeriodicalIF":0.0,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144512974","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Proof Is in the Plumage: A Method for Detecting Dietary Ethanol Exposure in Birds by Testing for Ethyl Glucuronide in Feathers.","authors":"Cynthia Y Wang-Claypool, Ammon Corl, Joseph Jones, Jimmy A McGuire, Rauri C K Bowie, Robert Dudley","doi":"10.1086/735669","DOIUrl":"https://doi.org/10.1086/735669","url":null,"abstract":"<p><p>AbstractEthanol is a naturally occurring molecule produced via fermentation of sugar-rich foods by yeast. Ethanol catabolism is followed by production of secondary metabolites such as ethyl glucuronide (EtG), which can be measured to provide a retrospective view of dietary exposure. To date, occurrence of this molecule has not been studied in vertebrates other than humans and several other mammalian taxa. Here, we describe a method of testing for the presence of EtG in bird feathers and livers using mass spectrometry. Birds that regularly consume fruit and nectar may accordingly be ingesting ethanol on a chronic basis. We predicted that avian species with diets rich in fermentable sugars consume physiologically significant amounts of ethanol and therefore accumulate detectable levels of EtG. The suitability of EtG assays was tested across 17 avian species representing a diversity of diets. Assays of avian feathers yielded positive results for 10 of 17 avian species; EtG was also present at substantial levels in the livers of two of five study species. We found that EtG was present in nectarivorous hummingbirds but also in species in other trophic niches (three granivores, one omnivore, three invertivores, and one vertivore). Dietary exposure to ethanol may thus be much more widespread than has previously been recognized, and diverse features of avian nutritional ecology (e.g., secondary consumption via ingestion of prey items) may contribute to its accumulation in tissues.</p>","PeriodicalId":519900,"journal":{"name":"Ecological and evolutionary physiology","volume":"98 2","pages":"70-82"},"PeriodicalIF":0.0,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144513000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Intraspecific Variation in Color and Carotenoids across Environmental Extremes in an African Cichlid.","authors":"Bethany L Williams, Lauren M Pintor, Matthew B Toomey, Suzanne M Gray","doi":"10.1086/735656","DOIUrl":"https://doi.org/10.1086/735656","url":null,"abstract":"<p><p>AbstractHuman activities frequently alter environmental conditions and affect the use of sexually selected traits like color in animals. However, the effects of environmental stressors are unlikely to be uniform across populations that experience different environments or between sexes. We aimed to understand the underlying genetic, environmental, and gene-by-environment contributions to color expression in males and females of a sexually dimorphic fish. <i>Pseudocrenilabrus multicolor</i> is a haplochromine cichlid found in environments that vary dramatically, particularly with respect to oxygen and turbidity levels. We reared fish from one swamp (hypoxic, clear) and one river (normoxic, turbid) population in a split-brood design (hypoxic/normoxic × clear/turbid) and then quantified color and carotenoid concentrations. As expected in this sexually dimorphic species, females were far less colorful than males. In males, hypoxia and turbidity were drivers of traits associated with color, suggesting that color was modified under energetically or visually unfavorable conditions. Males in the hypoxic treatment from both populations were not as bright as males reared under normoxic conditions, which corresponds to results observed in wild fish. Males reared in turbid conditions were also marginally less bright along the ventral surface than males reared in clear water. Rearing under turbid conditions reduced carotenoid concentrations in male skin, but carotenoids were not correlated with spectral characteristics of male color. We did not find effects of population on color traits, suggesting that differences in color between wild populations are due to plastic rather than fixed genetic effects. Overall, we provide evidence that hypoxia and turbidity affect signaling traits, although the consequences for mating success remain to be determined.</p>","PeriodicalId":519900,"journal":{"name":"Ecological and evolutionary physiology","volume":"98 2","pages":"57-69"},"PeriodicalIF":0.0,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144512976","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sexual Dimorphism in Red Blood Cell Mitochondrial Respiration during Breeding Fasts in King Penguins.","authors":"Nina Cossin-Sevrin, Céline Bocquet, Camille Lemonnier, Thomas Faulmann, Natacha Garcin, Mathilde Lejeune, Pierre Bize, Jean-Patrice Robin, Katja Anttila, Suvi Ruuskanen, Vincent A Viblanc","doi":"10.1086/736013","DOIUrl":"https://doi.org/10.1086/736013","url":null,"abstract":"<p><p>AbstractBecause of their extended fasting period on land during breeding, male king penguins have been extensively studied in order to unravel the physiological adaptations that enable them to fast while having to find a partner, defend their territory, or brood their offspring. While the different phases of fasting and the nature of the metabolic fuels used are well characterized in male king penguins, few studies have focused on the efficiency of the conversion of the metabolic resources into energy at a cellular level through mitochondrial respiration. Furthermore, little information is available on females in general while they experience fasting periods. Here, we measured mitochondrial respiration rates of red blood cells (RBCs) at the beginning (3 d) and end (10 d) of a natural egg-incubation fast in male and female king penguins. We tested whether RBC mitochondrial metabolism and its efficiency are modulated by fasting duration in free-living king penguins but also assessed whether this modulation is sex specific. In response to fasting, the respiration allocated to ATP synthesis in RBCs decreased in both sexes. Interestingly, RBC mitochondrial metabolic rates were higher in females at any stage of fasting. Furthermore, RBC mitochondrial metabolism efficiency decreased in males after 10 d of fasting but remained constant in females. Our results demonstrate that RBC mitochondrial metabolism is context and state dependent, differing between sexes and changing with fasting. They underline the importance of taking both sexes into account in physiological studies, where females remain underrepresented.</p>","PeriodicalId":519900,"journal":{"name":"Ecological and evolutionary physiology","volume":"98 2","pages":"96-110"},"PeriodicalIF":0.0,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144512999","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"High-Protein Diets Shorten Female but Not Male Lifespans and Have Minimal Effects on Egg Production in the Migratory Locust.","authors":"Sydney Millerwise, Stav Talal, Phoenix Pulver, Emma Goethe, Geoffrey Osgood, Emily Cossey, Rick Overson, Jon Harrison, Arianne Cease","doi":"10.1086/735836","DOIUrl":"https://doi.org/10.1086/735836","url":null,"abstract":"<p><p>AbstractIn many species, reproduction and lifespan are maximized at different dietary protein-to-carbohydrate (p∶c) ratios. Protein-biased diets tend to favor higher reproduction, while carbohydrate-biased diets tend to favor longer lifespans, but the mechanisms responsible for the apparent survival costs of reproduction remain unclear. Prior studies of this topic for females have primarily measured egg production, which could be an inadequate measure of fitness, and have not assessed the rate and timing of reproduction across lifespan, which can provide insights into fitness costs and benefits. To test how variation in dietary p∶c ratio effects are integrated across whole lifespans, we reared migratory locusts (<i>Locusta migratoria</i>) from fifth instar through adulthood on one of three artificial isocaloric diets varying in p∶c ratios (14p∶28c, 21p∶21c, 35p∶7c). We then put pairs of locusts in cages and each week measured male and female survival, the number of eggs and egg pods laid, and hatchlings per reproductive pair throughout the lifespan. Carbohydrate-biased diets increased female lifespans, but macronutrient content had no effect on male lifespans. Locusts eating a carbohydrate-biased diet incurred the cost of a 1-wk delay in the onset of egg laying; however, macronutrient balance did not affect the total number of hatchlings produced over their entire lifespans. Locusts consuming protein-biased diets laid more eggs per pod but fewer total egg pods, and their eggs were lighter than eggs laid by locusts on other diets. Earlier reproduction did not appear to fully explain the reduced longevity of locusts on high-protein diets, as locusts feeding on a balanced diet had similar reproductive schedules but had longer lifespans. In summary, our data show that reproductively active females are more susceptible to the negative effects of high protein on longevity than males and that macronutrient balance affects some nuances of egg production but does not affect overall hatchling success in lab populations. Macronutrient balance may have a greater impact on reproductive success in field populations, depending on predation pressures (reproducing earlier may be paramount), food availability (hatchlings from larger eggs may be more robust to starvation), or other factors.</p>","PeriodicalId":519900,"journal":{"name":"Ecological and evolutionary physiology","volume":"98 2","pages":"83-95"},"PeriodicalIF":0.0,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144512975","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}