Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology最新文献

{"title":"Physiological responses of the invasive blue crabs Callinectes sapidus to salinity variations: Implications for adaptability and invasive success","authors":"Inma Herrera ,&nbsp;Gustavo F. de Carvalho-Souza ,&nbsp;Enrique González-Ortegón","doi":"10.1016/j.cbpa.2024.111709","DOIUrl":"10.1016/j.cbpa.2024.111709","url":null,"abstract":"<div><p>This study provides a comprehensive analysis of the eco-physiological responses of the blue crab (<em>Callinectes sapidus</em>) to variations in salinity, shedding light on its adaptability and invasive success in aquatic environments. Gender-specific differences in osmoregulation and Electron Transport System (ETS) activity highlight the importance of considering sex-specific aspects when understanding the physiological responses of invasive species. Females exhibited increased ETS activity at lower salinities, potentially indicative of metabolic stress, while males displayed constant ETS activity across a range of salinities. Osmoregulatory capacity which depended on gender and salinity, was efficient within meso-polyhaline waters but decreased at higher salinities, particularly in males. These findings provide valuable understandings into how <em>C. sapidus</em> specimens in an invaded area responds to salinity changes, important for considerate its distribution through saline pathways during tidal cycle fluctuations. This study shows the importance of interdisciplinary research for effective management of invasive species and conservation of affected aquatic ecosystems.</p></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1095643324001363/pdfft?md5=85adfaabc34fc29b3c94822c81d0d877&pid=1-s2.0-S1095643324001363-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141762780","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"High levels of mitochondrial dynamics, autophagy, and apoptosis contribute to stable testicular status in hibernating Daurian ground squirrels","authors":"Zhe Wang ,&nbsp;Ming-Di Wang ,&nbsp;Xing-Chen Wang ,&nbsp;Le Chen ,&nbsp;Lu-Fan Li ,&nbsp;Li-Na Jiang ,&nbsp;Jin-Hui Xu ,&nbsp;Kai Dang","doi":"10.1016/j.cbpa.2024.111705","DOIUrl":"10.1016/j.cbpa.2024.111705","url":null,"abstract":"<div><p>Daurian ground squirrels (<em>Spermophilus dauricus</em>) experience various stress states during winter hibernation, but the impact on testicular function remains unclear. This study focused on the effects of changes in testicular autophagy, apoptosis, and mitochondrial homeostasis signaling pathways at various stages on the testes of Daurian ground squirrels. Results indicated that: (1) During winter hibernation, there was a significant increase in seminiferous tubule diameter and seminiferous epithelium thickness compared to summer. Spermatogonia number and testosterone, follicle-stimulating hormone (FSH), and luteinizing hormone (LH) levels were higher during inter-bout arousal, suggesting that the testes remained stable during hibernation. (2) An increased number of mitochondria with intact morphology were observed during hibernation, indicating that mitochondrial homeostasis may contribute to testicular stability. (3) DNA fragmentation was evident in the testes during the hibernation and inter-bout arousal stages, with the highest level of caspase3 enzyme activity detected during inter-bout arousal, together with elevated levels of Bax/Bcl-2 and Lc3 II/Lc3 I, indicating an up-regulation of apoptosis and autophagy signaling pathways during hibernation. (4) The abundance of DRP1, MFF, OPA1, and MFN2 proteins was increased, suggesting an up-regulation of mitochondrial dynamics-related pathways. Overall, testicular autophagy, apoptosis, and mitochondrial homeostasis-related signaling pathways were notably active in the extreme winter environment. The well-maintained mitochondrial morphology may favor the production of reproductive hormones and support stable testicular morphology.</p></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141735739","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of procedural handling on the physiological effects of alfaxalone anaesthesia in the ball python (Python regius)","authors":"Lauren E. James ,&nbsp;Mads F. Bertelsen ,&nbsp;Tobias Wang ,&nbsp;Catherine J.A. Williams","doi":"10.1016/j.cbpa.2024.111704","DOIUrl":"10.1016/j.cbpa.2024.111704","url":null,"abstract":"<div><p>To describe the cardiovascular changes following intramuscular (handled) and intravascular (undisturbed, via intraarterial catheter) alfaxalone administration, we studied 20 healthy ball pythons (<em>Python regius</em>) in a randomised, prospective study. The pythons were instrumented with occlusive arterial catheters to facilitate undisturbed, continuous monitoring of heart rate and blood pressure. Six pythons were administered intramuscular (IM) saline, followed by 20 mg/kg IM alfaxalone, and were manually restrained for both injections. Six pythons received intraarterial (IA) saline, followed by 10 mg/kg IA alfaxalone, and remained undisturbed for both injections. Arterial blood samples were taken at 0, 12 and 60 min post-injection, and heart rate and blood pressure were recorded for 60 min. The remaining eight snakes received 20 mg/kg IM or 10 mg/kg IA alfaxalone (<em>n</em> = 4 per treatment) and were not handled for intubation 10 min post-injection, to examine the effects of handling during anaesthesia. IM administration of 20 mg/kg alfaxalone or an equivalent volume of saline elicited a profound tachycardia and hypertension, which recovered to resting values after 20 min. However, when 10 mg/kg alfaxalone or saline were injected IA, mild hypotension and a lower magnitude tachycardia occurred. Arterial PCO₂ and PO₂, pH and lactate concentrations did not change following IA alfaxalone, but an acidosis was observed during IM alfaxalone anaesthesia. There were no significant changes in plasma catecholamines and corticosterone among treatments. Handling for injection and during anaesthesia associated with intubation significantly affects cardiovascular parameters, whereas alfaxalone per se only elicits minor changes in cardiovascular physiology.</p></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141749806","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The effects of acute ammonia stress on liver antioxidant, immune and metabolic responses of juvenile yellowfin tuna (Thunnus albacares)","authors":"Yongyue Sun ,&nbsp;Zhengyi Fu ,&nbsp;Zhenhua Ma","doi":"10.1016/j.cbpa.2024.111707","DOIUrl":"10.1016/j.cbpa.2024.111707","url":null,"abstract":"<div><p>The impact of acute ammonia nitrogen (NH₃−N) stress on the antioxidant, immune, and metabolic capabilities of the liver in juvenile yellowfin tuna (<em>Thunnus albacares</em>) is not yet fully understood. This study set NH₃-N concentrations at 0 (natural seawater, control group), 5, and 10 mg/L, and sampled the liver at 6, 24, and 36 h for analysis. As time progresses, NH₃-N exposure leads to an increase in malondialdehyde (MDA) concentrations. The activity of superoxide dismutase (SOD) and the relative expression levels of related genes, as well as the activity of immune enzymes and ATPase, decrease. The levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and interleukin-10 (IL-10) exhibit different fluctuation patterns. Low concentrations of NH₃-N increase the activity of catalase (CAT) and glutathione peroxidase (GHS-PX) and the relative expression levels of the Na⁺K⁺-ATPase gene. The relative expression levels of the interleukin-6 receptor (IL-6r) gene show a decreasing trend. High concentrations of NH₃-N decrease the activity of CAT, GSH-PX, and the relative expression levels of related genes. When the NH₃-N concentration is below 5 mg/L, the stress duration should not exceed 36 h. When the NH₃-N concentration is between 5 and 10 mg/L, the stress duration should not exceed 24 h, otherwise, it will have a negative impact on the liver of the juvenile yellowfin tuna. This study provides scientific data for the artificial breeding and recirculating aquaculture of juvenile yellowfin tuna.</p></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141735740","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tissue-specific effects of temperature and salinity on the cell cycle and apoptosis in the Nile Tilapia (Oreochromis niloticus)","authors":"Rachel M. Palmer,&nbsp;Arika Sandbach,&nbsp;Bradley A. Buckley","doi":"10.1016/j.cbpa.2024.111706","DOIUrl":"10.1016/j.cbpa.2024.111706","url":null,"abstract":"<div><p>The Nile Tilapia (<em>Oreochromis niloticus</em>) evolved in warm, freshwater rivers, but possesses a broad physiological tolerance to a range of environmental conditions. Due to this hardiness and resilience, this species has been successfully introduced to regions widely outside of its native range. Here, we examine the impact of temperature and salinity variation on this species at the sub-lethal level. Specifically, Nile Tilapia were exposed to two temperatures (21 °C or 14 °C) and three salinities (0, 16, 34 ppt) for 1-h. Given their native habitat, the 21 °C / 0 ppt exposure was considered the control condition. Both cell cycle arrest and apoptosis represent sub-lethal but deleterious responses to environmental stress. Flow cytometry was used to assess the percentage of cells in a given stage of the cell cycle as a metric of cell cycle arrest in spleen and liver. Percentage of apoptotic cells were also quantified. Spleen was more sensitive to cold stress, demonstrating an increase in cells in the G2/M phase after experimental treatment. Liver, however, was more sensitive to salinity stress, with a significant increase in cells stalled in G2/M phase at higher salinities, which is in keeping with the freshwater evolutionary history of the species. A modest apoptotic signal was observed in liver but not in spleen. Together, these findings demonstrate that even short, acute exposures to cold temperatures and elevated salinity can cause sub-lethal damage in a species that is otherwise tolerant of environmental stress at the whole organism level.</p></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141735741","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of feeding status and water temperature on swimming performance in juvenile chum salmon (Oncorhynchus keta)","authors":"Mitsuru Torao ,&nbsp;Wenda Cui ,&nbsp;Munetaka Shimizu","doi":"10.1016/j.cbpa.2024.111702","DOIUrl":"10.1016/j.cbpa.2024.111702","url":null,"abstract":"<div><p>We examined the effects of feeding status in freshwater and then subsequent seawater rearing temperature on growth, critical swimming speed (<em>U</em>_crit), and circulating insulin-like growth factor (IGF)-1 in juvenile chum salmon. Chum salmon fry weighing about 1.0 g were fed at 0, 1 or 3% body weight (BW) for 5 days in freshwater, acclimated to seawater at 4, 7 or 10 °C and then reared for 8 days with satiation feeding. Both freshwater feeding history and seawater rearing temperature affected fork length (FL), BW, IGF-1 levels and relative <em>U</em>_crit (FL/s) 8 days after seawater transfer. Relative <em>U</em>_crit positively correlated with FL and IGF-1 levels, suggesting an improvement in swimming ability attributed to growth. In a second experiment, we examined the effects of body size and growth on serum IGF-1, IGF-binding proteins (IGFBPs), and <em>U</em>_crit. The chum salmon fry were sorted into large (1.5 g) or small (1.2 g) groups. They were acclimated to seawater at 10 °C and fed at 1 or 4% BW for two months. Despite the differences in serum IGF-1 levels, there were no differences in relative <em>U</em>_crit among the groups. In contrast, absolute <em>U</em>_crit (cm/s) was correlated with body size/condition and IGF-1 levels. Absolute <em>U</em>_crit negatively correlated with serum IGFBP-1b levels. The present study showed that poor feeding in freshwater followed by transfer to seawater at low temperature has profound effects on the growth and swimming ability of juvenile chum salmon, which may be linked to alterations in circulating IGF-1 and IGFBPs.</p></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141728362","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Knock down to level up: Reframing RNAi for invertebrate ecophysiology","authors":"Jacqueline E. Lebenzon ,&nbsp;Jantina Toxopeus","doi":"10.1016/j.cbpa.2024.111703","DOIUrl":"10.1016/j.cbpa.2024.111703","url":null,"abstract":"<div><p>Comparative ecophysiologists strive to understand physiological problems in non-model organisms, but molecular tools such as RNA interference (RNAi) are under-used in our field. Here, we provide a framework for invertebrate ecophysiologists to use RNAi to answer questions focused on physiological processes, rather than as a tool to investigate gene function. We specifically focus on non-model invertebrates, in which the use of other genetic tools (<em>e.g.</em>, genetic knockout lines) is less likely. We argue that because RNAi elicits a temporary manipulation of gene expression, and resources to carry out RNAi are technically and financially accessible, it is an effective tool for invertebrate ecophysiologists. We cover the terminology and basic mechanisms of RNA interference as an accessible introduction for “non-molecular” physiologists, include a suggested workflow for identifying RNAi gene targets and validating biologically relevant gene knockdowns, and present a hypothesis-testing framework for using RNAi to answer common questions in the realm of invertebrate ecophysiology. This review encourages invertebrate ecophysiologists to use these tools and workflows to explore physiological processes and bridge genotypes to phenotypes in their animal(s) of interest.</p></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141728363","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Baseline and stress-induced changes in plasma bacterial killing ability against gram-negative bacteria are partially mediated by the complement system in Rhinella diptycha toads","authors":"Stefany Antunes de Oliveira Rosa,&nbsp;Braz Titon Junior,&nbsp;Aymam Cobo de Figueiredo,&nbsp;Alan Siqueira Lima,&nbsp;Fernando Ribeiro Gomes,&nbsp;Stefanny Christie Monteiro Titon","doi":"10.1016/j.cbpa.2024.111701","DOIUrl":"10.1016/j.cbpa.2024.111701","url":null,"abstract":"<div><p>The plasma bacterial killing ability (BKA) is modulated by the stress response in vertebrates, including amphibians. The complement system is an effector mechanism comprised of a set of proteins present in the plasma that once activated can promote bacterial lysis. Herein, we investigated whether changes in plasma BKA as a result of the acute stress response and an immune challenge are mediated by the complement system in <em>Rhinella diptycha</em> toads. Additionally, we investigated whether the observed changes in plasma BKA are associated with changes in plasma corticosterone levels (CORT). We subjected adult male toads to a restraint or an immune challenge (with three concentrations of <em>Aeromonas hydrophila</em> heat inactivated), and then evaluated the plasma BKA against <em>A. hydrophila, in vitro</em>. We determined the complement system activity on plasma BKA, by treating the plasma (baseline, 1 h and 24 h post-restraint, and after the immune challenge) with ethylenediaminetetraacetic acid, heat, or protease. Our results showed increased CORT 1 h and 24 h after restraint and decreased plasma BKA 24 h post-restraint. The inhibitors of the complement system decreased the plasma BKA compared with untreated plasma at all times (baseline, 1 h, and 24 h after restraint), demonstrating that the plasma BKA activity is partially mediated by the complement system. The immune challenge increased CORT, with the highest values being observed in the highest bacterial concentration, compared with control. The plasma BKA was not affected by the immune challenge but was demonstrated to be partially mediated by the complement system. Our results demonstrated that restraint and the immune challenge activated the hypothalamus-pituitary-interrenal axis, by increasing plasma CORT levels in <em>R. diptycha</em>. Also, our results demonstrated the complement system is participative in the plasma BKA for baseline and post-stress situations in these toads.</p></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141728361","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Two faces of one coin: Beneficial and deleterious effects of reactive oxygen species during short-term acclimation to hypo-osmotic stress in a decapod crab","authors":"Georgina A. Rivera-Ingraham ,&nbsp;Diana Martínez-Alarcón ,&nbsp;Dimitri Theuerkauff ,&nbsp;Aude Nommick ,&nbsp;Jehan-Hervé Lignot","doi":"10.1016/j.cbpa.2024.111700","DOIUrl":"10.1016/j.cbpa.2024.111700","url":null,"abstract":"<div><p>Exposure to environmental changes often results in the production of reactive oxygen species (ROS), which, if uncontrolled, leads to loss of cellular homeostasis and oxidative distress. However, at physiological levels these same ROS are known to be key players in cellular signaling and the regulation of key biological activities (oxidative eustress). While ROS are known to mediate salinity tolerance in plants, little is known for the animal kingdom. In this study, we use the Mediterranean crab <em>Carcinus aestuarii,</em> highly tolerant to salinity changes in its environment, as a model to test the healthy or pathological role of ROS due to exposure to diluted seawater (dSW). Crabs were injected either with an antioxidant [<em>N</em>-acetylcysteine (NAC), 150 mg·kg⁻¹] or phosphate buffered saline (PBS). One hour after the first injection, animals were either maintained in seawater (SW) or transferred to dSW and injections were carried out at 12-h intervals. After ≈48 h of salinity change, all animals were sacrificed and gills dissected for analysis. NAC injections successfully inhibited ROS formation occurring due to dSW transfer. However, this induced 55% crab mortality, as well as an inhibition of the enhanced catalase defenses and mitochondrial biogenesis that occur with decreased salinity. Crab osmoregulatory capacity under dSW condition was not affected by NAC, although it induced in anterior (non-osmoregulatory) gills a 146-fold increase in Na⁺/K⁺/2Cl⁻ expression levels, reaching values typically observed in osmoregulatory tissues. We discuss how ROS influences the physiology of anterior and posterior gills, which have two different physiological functions and strategies during hyper-osmoregulation in dSW.</p></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1095643324001272/pdfft?md5=5a8fadf0ae55d186dfc011fdc3f2c0bd&pid=1-s2.0-S1095643324001272-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141635939","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hormonal dynamics of matrotrophy vs. lecithotrophy in live-bearing fish reproduction","authors":"Saeid Panahi Hassan Barough ,&nbsp;Monserrat Suárez-Rodríguez ,&nbsp;Andrea S. Aspbury ,&nbsp;José Jaime Zúñiga-Vega ,&nbsp;Caitlin R. Gabor","doi":"10.1016/j.cbpa.2024.111699","DOIUrl":"10.1016/j.cbpa.2024.111699","url":null,"abstract":"<div><p>We explored the relationship between gestational states, fecundity, and steroid hormone levels in three species of live-bearing fish with different maternal provisioning strategies. We studied two lecithotrophic species, <em>Gambusia affinis</em> and <em>Xiphophorus couchianus</em>, where embryos feed exclusively on yolk stored in the eggs, and one matrotrophic species, <em>Heterandria formosa</em>, which actively transfers nutrients to embryos through a follicular placenta. We measured water-borne cortisol, estradiol, and progesterone along with brood size (fecundity) and gestational stage(s). We examined the physiological costs of both maternal provisioning modes. Matrotrophy likely imposes energetic demands due to active nutrient transfer, while lecithotrophy may incur costs from carrying many large embryos. We hypothesized that fecundity, gestational stage, and hormones would covary differently in lecithotrophic vs. matrotrophic species. We found no relationships between hormones and fecundity or gestational stage in any species. However, in <em>H. formosa</em>, we found a positive relationship between estradiol levels and female mass, and a negative relationship between progesterone levels and female mass indicating a change in the circulating levels of both hormones as females grow. We observed differences in average hormone levels among species: the matrotrophic species had higher progesterone and lower estradiol compared to lecithotrophic species. Higher estradiol in lecithotrophic species may relate to egg yolk formation, while placental structures could play a role in progesterone production in matrotrophic species. Elevated cortisol in <em>H. formosa</em> suggests either higher energetic costs or a preparative role for reproduction. Our findings highlight progesterone's importance in maintaining gestation in matrotrophic species, like other placental species.</p></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141617703","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}