Pub Date : 2024-11-20DOI: 10.1016/j.jtherbio.2024.104013
Antonis G. Papadopoulos , Panagiota Koskinioti , Kostas D. Zarpas , Paraschos Prekas , John S. Terblanche , Daniel A. Hahn , Nikos T. Papadopoulos
The highly invasive Mediterranean fruit fly (medfly), Ceratitis capitata (Wiedemann) (Diptera: Tephritidae), is currently expanding its geographic distribution into cooler temperate areas of the Northern Hemisphere. In marginal conditions, the invasion potential of medfly depends in part on innate tolerance to the novel environmental conditions. Physiological tolerances are potentially influenced by interactions among multiple factors, such as organism age or reproductive maturity, sex, and mating status. Furthermore, the relationships between the above factors and tolerances may differ among geographically distinct populations. Here, the effects of age and mating status on thermal tolerance of three geographically distinct medfly populations along a latitudinal gradient ranging from Greece (Crete & Volos) to Croatia (Dubrovnik) were examined. The upper and lower critical thermal limits (scored as loss of neuromuscular function during controlled cooling or heating) of adult males and females (a) at 1-, 6-, 15-, and 35 days old and of (b) both mated and virgin flies were assessed. Results showed that estimates of lower and upper thermal limits (CTmin and CTmax) were both population- and age-dependent. In most age classes tested, CTmin values were lower for the adults obtained from Crete and higher for those from Dubrovnik. CTmax values were lower for the females from Dubrovnik compared to the females from any other population on day one after emergence but not on days 6, 15 and 35. Differences among populations were observed across different age classes both for cold and heat tolerance but mostly in CTmin estimates. Mating status had a little effect on cold and heat tolerance. Complex patterns of thermal limit variation within and among populations suggest a suite of factors determine population-level mortality from thermal extremes under field conditions in medfly. These results contribute towards understanding the invasion dynamics of medfly and its range expansion to northern, more temperate regions of Europe.
{"title":"Age and mating status have complex but modest effects on the critical thermal limits of adult Mediterranean fruit flies from geographically divergent populations","authors":"Antonis G. Papadopoulos , Panagiota Koskinioti , Kostas D. Zarpas , Paraschos Prekas , John S. Terblanche , Daniel A. Hahn , Nikos T. Papadopoulos","doi":"10.1016/j.jtherbio.2024.104013","DOIUrl":"10.1016/j.jtherbio.2024.104013","url":null,"abstract":"<div><div>The highly invasive Mediterranean fruit fly (medfly), <em>Ceratitis capitata</em> (Wiedemann) (Diptera: Tephritidae), is currently expanding its geographic distribution into cooler temperate areas of the Northern Hemisphere. In marginal conditions, the invasion potential of medfly depends in part on innate tolerance to the novel environmental conditions. Physiological tolerances are potentially influenced by interactions among multiple factors, such as organism age or reproductive maturity, sex, and mating status. Furthermore, the relationships between the above factors and tolerances may differ among geographically distinct populations. Here, the effects of age and mating status on thermal tolerance of three geographically distinct medfly populations along a latitudinal gradient ranging from Greece (Crete & Volos) to Croatia (Dubrovnik) were examined. The upper and lower critical thermal limits (scored as loss of neuromuscular function during controlled cooling or heating) of adult males and females (a) at 1-, 6-, 15-, and 35 days old and of (b) both mated and virgin flies were assessed. Results showed that estimates of lower and upper thermal limits (CTmin and CTmax) were both population- and age-dependent. In most age classes tested, CTmin values were lower for the adults obtained from Crete and higher for those from Dubrovnik. CTmax values were lower for the females from Dubrovnik compared to the females from any other population on day one after emergence but not on days 6, 15 and 35. Differences among populations were observed across different age classes both for cold and heat tolerance but mostly in CTmin estimates. Mating status had a little effect on cold and heat tolerance. Complex patterns of thermal limit variation within and among populations suggest a suite of factors determine population-level mortality from thermal extremes under field conditions in medfly. These results contribute towards understanding the invasion dynamics of medfly and its range expansion to northern, more temperate regions of Europe.</div></div>","PeriodicalId":17428,"journal":{"name":"Journal of thermal biology","volume":"126 ","pages":"Article 104013"},"PeriodicalIF":2.9,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142716505","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study examines the impact of Holstein dry cows' prenatal heat tolerance (n = 180) on their calves' thermoregulation and immunity. Holstein cows (body condition score 3.29 ± 0.39, parity 2.64 ± 0.79) were monitored for body temperature (BT), respiratory rate (RR), and microenvironmental temperature and humidity twice daily for seven days during heat stress. Mixed-effects model and cluster method identified heat-tolerant (n = 68) and heat-sensitive (n = 114) dry cows. Once cows gave birth, the RR and BT of 2-day-old calves were recorded every 2 h for two days, totaling five measurements per day, to assess thermoregulatory responses using generalized linear mixed models. Calves in the heat-tolerant group had a better thermoregulatory response than the heat-sensitive group, RR of heat-tolerant calves was significantly higher than the heat-sensitive calves (P = 0.02). Plasma indicators were analyzed to assess calf immunity. Heat-tolerant calves had significantly lower plasma cortisol, tumor necrosis factor-alpha, interleukin 2, interleukin 4, interleukin 6, and interleukin 10 concentrations compared to heat-sensitive calves (P < 0.05). In both cows and calves, plasma cortisol concentrations in the heat-tolerant groups were lower than those in heat-sensitive groups. In comparison, plasma heat shock protein 70 and heat shock protein 90 concentrations were higher (P < 0.05). In conclusion, calves born to heat-tolerant cows had higher thermoregulation and immunity than calves born to heat-sensitive cows when exposed to heat stress.
{"title":"Impact of prenatal heat tolerance in holstein dry cows on their calves' thermoregulation and immunity.","authors":"Xiaoyang Chen, Chenyang Li, Tingting Fang, Junhu Yao, Xianhong Gu","doi":"10.1016/j.jtherbio.2024.104015","DOIUrl":"https://doi.org/10.1016/j.jtherbio.2024.104015","url":null,"abstract":"<p><p>This study examines the impact of Holstein dry cows' prenatal heat tolerance (n = 180) on their calves' thermoregulation and immunity. Holstein cows (body condition score 3.29 ± 0.39, parity 2.64 ± 0.79) were monitored for body temperature (BT), respiratory rate (RR), and microenvironmental temperature and humidity twice daily for seven days during heat stress. Mixed-effects model and cluster method identified heat-tolerant (n = 68) and heat-sensitive (n = 114) dry cows. Once cows gave birth, the RR and BT of 2-day-old calves were recorded every 2 h for two days, totaling five measurements per day, to assess thermoregulatory responses using generalized linear mixed models. Calves in the heat-tolerant group had a better thermoregulatory response than the heat-sensitive group, RR of heat-tolerant calves was significantly higher than the heat-sensitive calves (P = 0.02). Plasma indicators were analyzed to assess calf immunity. Heat-tolerant calves had significantly lower plasma cortisol, tumor necrosis factor-alpha, interleukin 2, interleukin 4, interleukin 6, and interleukin 10 concentrations compared to heat-sensitive calves (P < 0.05). In both cows and calves, plasma cortisol concentrations in the heat-tolerant groups were lower than those in heat-sensitive groups. In comparison, plasma heat shock protein 70 and heat shock protein 90 concentrations were higher (P < 0.05). In conclusion, calves born to heat-tolerant cows had higher thermoregulation and immunity than calves born to heat-sensitive cows when exposed to heat stress.</p>","PeriodicalId":17428,"journal":{"name":"Journal of thermal biology","volume":"127 ","pages":"104015"},"PeriodicalIF":2.9,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142837301","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-28DOI: 10.1016/j.jtherbio.2024.103997
Belén Gallego , José R. Verdú , Yolanda Jiménez-Ruiz , Jorge M. Lobo
The study of cold tolerance is imperative for understanding insect activity across spatial and temporal gradients. Here, we assessed various physiological variables to discern the response to cold stress in Mediterranean earth-boring dung beetles, utilizing an infrared thermography protocol initially developed for detecting heat stress variables.
Subsequently, we conducted a joint analysis of heat and cold stress variables to explore the extent of congruence between their responses. Our findings indicate that the temperatures at which activity ceases and resumes are the most effective variables for distinguishing between the cold thermal strategies of the studied species. Moreover, our analyses revealed a positive association between the variables representing heat and cold tolerances, wherein species with higher upper limits of heat tolerance also exhibit higher temperatures at which they become immobilized by cold.
This result suggest that adaptations to endure heat may compromise resistance to cold in these insects. We hypothesize about the main factors (loss of wings, fusion of the elytra, and accumulation of haemolymph) that could have represented radical modifications in the Mediterranean clades of Geotrupinae. These factors may have reshaped their life history and thermal physiology, potentially impairing thermogenesis, reducing cold hardiness and freezing resistance.
{"title":"Searching for variables representing the response to cold stress in mediterranean Geotrupinae reveals an association between heat and cold tolerances","authors":"Belén Gallego , José R. Verdú , Yolanda Jiménez-Ruiz , Jorge M. Lobo","doi":"10.1016/j.jtherbio.2024.103997","DOIUrl":"10.1016/j.jtherbio.2024.103997","url":null,"abstract":"<div><div>The study of cold tolerance is imperative for understanding insect activity across spatial and temporal gradients. Here, we assessed various physiological variables to discern the response to cold stress in Mediterranean earth-boring dung beetles, utilizing an infrared thermography protocol initially developed for detecting heat stress variables.</div><div>Subsequently, we conducted a joint analysis of heat and cold stress variables to explore the extent of congruence between their responses. Our findings indicate that the temperatures at which activity ceases and resumes are the most effective variables for distinguishing between the cold thermal strategies of the studied species. Moreover, our analyses revealed a positive association between the variables representing heat and cold tolerances, wherein species with higher upper limits of heat tolerance also exhibit higher temperatures at which they become immobilized by cold.</div><div>This result suggest that adaptations to endure heat may compromise resistance to cold in these insects. We hypothesize about the main factors (loss of wings, fusion of the elytra, and accumulation of haemolymph) that could have represented radical modifications in the Mediterranean clades of Geotrupinae. These factors may have reshaped their life history and thermal physiology, potentially impairing thermogenesis, reducing cold hardiness and freezing resistance.</div></div>","PeriodicalId":17428,"journal":{"name":"Journal of thermal biology","volume":"126 ","pages":"Article 103997"},"PeriodicalIF":2.9,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142692928","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-19DOI: 10.1016/j.jtherbio.2024.103994
Hye Ran Kim, Pilnam Seong, Kuk-Hwan Seol, Jong-Eun Park, Hana Kim, Woncheoul Park, Jin Ho Cho, Sung Dae Lee
High environmental temperatures lead to metabolic changes, body weight reduction, and high mortality in chickens, affecting poultry production worldwide. This study aimed to evaluate the effects of heat stress, assessed by the temperature-humidity index (THI), on the growth performance, physiological response, carcasses, and hematological traits of broilers. A total of 200 broilers (between 17 and 31 days old) were kept in thermoneutral conditions (21 °C; 60% relative humidity, RH) for 3 days during the adaptation period, followed by 14 days of exposure to the experimental treatments. The broilers were randomly assigned to 4 groups of equal size and raised in a temperature-humidity controlled chamber with THI ranging from 67 (21 °C; RH 60%) to 84 (33 °C; RH 60%). In boilers subjected to severe heat stress (THI 84), feed intake (-30%) and body weight gain (-51%) were decreased (P < 0.05) in comparison with the performance parameters of broilers under thermoneutral conditions (THI 67). Moreover, under heat stress, the respiration rate and rectal temperature significantly increased (P < 0.05), whereas blood parameters showed reduced levels of red blood cells, hemoglobin, white blood cells, lymphocytes, and electrolytes (K+, Na+). Regarding carcass traits, differences were observed in broilers exposed to severe heat stress, particularly in the reduction of the bursa of Fabricius as an immune organ growth index (P < 0.05). This study shows that severe heat stress, as revealed by the high THI levels, alters the physiological reactions and metabolic processes of broiler chickens, leading to negative effects on their growth.
{"title":"Effects of heat stress on growth performance, physiological responses, and carcass traits in broilers.","authors":"Hye Ran Kim, Pilnam Seong, Kuk-Hwan Seol, Jong-Eun Park, Hana Kim, Woncheoul Park, Jin Ho Cho, Sung Dae Lee","doi":"10.1016/j.jtherbio.2024.103994","DOIUrl":"https://doi.org/10.1016/j.jtherbio.2024.103994","url":null,"abstract":"<p><p>High environmental temperatures lead to metabolic changes, body weight reduction, and high mortality in chickens, affecting poultry production worldwide. This study aimed to evaluate the effects of heat stress, assessed by the temperature-humidity index (THI), on the growth performance, physiological response, carcasses, and hematological traits of broilers. A total of 200 broilers (between 17 and 31 days old) were kept in thermoneutral conditions (21 °C; 60% relative humidity, RH) for 3 days during the adaptation period, followed by 14 days of exposure to the experimental treatments. The broilers were randomly assigned to 4 groups of equal size and raised in a temperature-humidity controlled chamber with THI ranging from 67 (21 °C; RH 60%) to 84 (33 °C; RH 60%). In boilers subjected to severe heat stress (THI 84), feed intake (-30%) and body weight gain (-51%) were decreased (P < 0.05) in comparison with the performance parameters of broilers under thermoneutral conditions (THI 67). Moreover, under heat stress, the respiration rate and rectal temperature significantly increased (P < 0.05), whereas blood parameters showed reduced levels of red blood cells, hemoglobin, white blood cells, lymphocytes, and electrolytes (K+, Na+). Regarding carcass traits, differences were observed in broilers exposed to severe heat stress, particularly in the reduction of the bursa of Fabricius as an immune organ growth index (P < 0.05). This study shows that severe heat stress, as revealed by the high THI levels, alters the physiological reactions and metabolic processes of broiler chickens, leading to negative effects on their growth.</p>","PeriodicalId":17428,"journal":{"name":"Journal of thermal biology","volume":"127 ","pages":"103994"},"PeriodicalIF":2.9,"publicationDate":"2024-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142894914","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-01DOI: 10.1016/j.jtherbio.2024.103983
Jake Shaw , Cole E. , Andrew J. Simpson , Christopher J. Tyler , Andrew T. Garrett
Introduction
There is considerable inter-individual variability in the physiological responses to environmental stressors and so to accurately assess and monitor changes in an individual's ability to cope with exercise-heat stress, a reliable protocol is required. The aim of this study was to examine the repeatability of a 90-min steady-state heat exercise bout with physiological and subjective variables, and performance during an incremental test to exhaustion post 90-min steady-state exercise.
Method
Sixteen mixed ability males (Age: 39 ± 15yrs; Height: 176.5 ± 4.8 cm; BM: 79.7 ± 10.3 kg; O2peak: 46.2 ± 8.6 ml/kg/min; PPO: 309 ± 39W) who trained at least three times a week undertook two 90-min steady-state – followed by an incremental protocol to exhaustion – cycling heat stress tests (HSTs) in a hot-humid environment (35 °C, 60%RH). Heart rate (HR), rectal ( re) and skin temperature (sk), rating of perceived exertion (RPE), thermal sensation (TS), and thermal comfort (TC) were measured throughout. Data was analysed using Intraclass Correlation Coefficients (ICC), technical error of measurement (TEM), Bland-Altman plots, t-tests, and Cohen's d to indicate magnitude of change.
Results
Physiological variables indicated good repeatability evident through moderate to strong ICC ratings, low magnitudes of change (d), lower mean biases compared to their respective calculated TEMs, and statistical non-significance, except HR90, ₸sk90, and ₸sk. Hydration status showed good repeatability except for urine osmolality (osmu90) and resting urine colour (colu). Perceptual variables showed encouraging repeatability apart from resting TS and mean TS. Performance data showed good repeatability overall, however 11 participants progressed to the incremental test to exhaustion in the second visit compared to 7 in the first.
Conclusion
Current data demonstrated favourable physiological, perceptual, and performance repeatability during repeated cycling HSTs in hot-humid conditions. However, given more participants progressed to the incremental trial to exhaustion protocol in the second visit, at least one familiarisation trial may improve the reliability of exercise capacity assessment.
{"title":"The repeatability of a cycling exercise-heat stress test in a male population","authors":"Jake Shaw , Cole E. , Andrew J. Simpson , Christopher J. Tyler , Andrew T. Garrett","doi":"10.1016/j.jtherbio.2024.103983","DOIUrl":"10.1016/j.jtherbio.2024.103983","url":null,"abstract":"<div><h3>Introduction</h3><div>There is considerable inter-individual variability in the physiological responses to environmental stressors and so to accurately assess and monitor changes in an individual's ability to cope with exercise-heat stress, a reliable protocol is required. The aim of this study was to examine the repeatability of a 90-min steady-state heat exercise bout with physiological and subjective variables, and performance during an incremental test to exhaustion post 90-min steady-state exercise.</div></div><div><h3>Method</h3><div>Sixteen mixed ability males (Age: 39 ± 15yrs; Height: 176.5 ± 4.8 cm; BM: 79.7 ± 10.3 kg; <span><math><mrow><mover><mi>V</mi><mo>˙</mo></mover></mrow></math></span>O<sub>2peak</sub>: 46.2 ± 8.6 ml/kg/min; PPO: 309 ± 39W) who trained at least three times a week undertook two 90-min steady-state – followed by an incremental protocol to exhaustion – cycling heat stress tests (HSTs) in a hot-humid environment (35 °C, 60%RH). Heart rate (HR), rectal (<span><math><mrow><mover><mi>T</mi><mo>‾</mo></mover></mrow></math></span> <em>r</em><sub><em>e</em></sub>) and skin temperature (<span><math><mrow><mover><mi>T</mi><mo>‾</mo></mover></mrow></math></span><sub><em>sk</em></sub>), rating of perceived exertion (RPE), thermal sensation (TS), and thermal comfort (TC) were measured throughout<strong>.</strong> Data was analysed using Intraclass Correlation Coefficients (ICC), technical error of measurement (TEM), Bland-Altman plots, <em>t</em>-tests, and Cohen's <em>d</em> to indicate magnitude of change.</div></div><div><h3>Results</h3><div>Physiological variables indicated good repeatability evident through moderate to strong ICC ratings, low magnitudes of change (<em>d</em>), lower mean biases compared to their respective calculated TEMs, and statistical non-significance, except HR90, ₸<sub><em>sk</em></sub>90, and ₸<sub><em>sk</em></sub>. Hydration status showed good repeatability except for urine osmolality (osm<sub>u</sub>90) and resting urine colour (col<sub>u</sub>). Perceptual variables showed encouraging repeatability apart from resting TS and mean TS. Performance data showed good repeatability overall, however 11 participants progressed to the incremental test to exhaustion in the second visit compared to 7 in the first.</div></div><div><h3>Conclusion</h3><div>Current data demonstrated favourable physiological, perceptual, and performance repeatability during repeated cycling HSTs in hot-humid conditions. However, given more participants progressed to the incremental trial to exhaustion protocol in the second visit, at least one familiarisation trial may improve the reliability of exercise capacity assessment.</div></div>","PeriodicalId":17428,"journal":{"name":"Journal of thermal biology","volume":"125 ","pages":"Article 103983"},"PeriodicalIF":2.9,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142577773","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-01DOI: 10.1016/j.jtherbio.2024.103988
Yu-Cheng Wang , Ya-Wen Chang , Fei Yang , Wei-Rong Gong , Jie Hu , Yu-Zhou Du
The invasive pest, Liriomyza trifolii, poses a significant threat to ornamental and vegetable plants. It spreads rapidly and causes large-scale outbreaks with pronounced thermotolerance. In this study, we developed L. trifolii strains adapted to high temperatures (strains designated 35 and 40); these were generated from a susceptible strain (designated S) by long-term thermal acclimation to 35 °C and 40 °C, respectively. Age-stage, two-sex life tables, thermal preferences, critical thermal limits, knockdown behaviors, eclosion and survival rates as well as expression of genes encoding heat shock proteins (Hsps) were compared for the three strains. Our findings indicated that the thermotolerance of L. trifolii was enhanced after long-term thermal acclimation, which suggested an adaptive plastic response to thermal stress. A trade-off between reproduction and thermotolerance was observed under thermal stress, potentially improving survival of the population and fostering adaptionary changes. Acclimation at 35 °C improved reproductive performance and population density of L. trifolii, particularly by enhancing the fecundity of female adults and accelerating the speed of development. Although the 40 strain exhibited the highest developmental speed and greater thermotolerance, it incurred a larger reproductive cost. This study provides a theoretical framework for monitoring and controlling leafminers and understanding their evolutionary adaptation to environmental changes.
{"title":"A potential trade-off between reproduction and enhancement of thermotolerance in Liriomyza trifolii populations driven by thermal acclimation","authors":"Yu-Cheng Wang , Ya-Wen Chang , Fei Yang , Wei-Rong Gong , Jie Hu , Yu-Zhou Du","doi":"10.1016/j.jtherbio.2024.103988","DOIUrl":"10.1016/j.jtherbio.2024.103988","url":null,"abstract":"<div><div>The invasive pest, <em>Liriomyza trifolii</em>, poses a significant threat to ornamental and vegetable plants. It spreads rapidly and causes large-scale outbreaks with pronounced thermotolerance. In this study, we developed <em>L. trifolii</em> strains adapted to high temperatures (strains designated 35 and 40); these were generated from a susceptible strain (designated S) by long-term thermal acclimation to 35 °C and 40 °C, respectively. Age-stage, two-sex life tables, thermal preferences, critical thermal limits, knockdown behaviors, eclosion and survival rates as well as expression of genes encoding heat shock proteins (<em>Hsps</em>) were compared for the three strains. Our findings indicated that the thermotolerance of <em>L. trifolii</em> was enhanced after long-term thermal acclimation, which suggested an adaptive plastic response to thermal stress. A trade-off between reproduction and thermotolerance was observed under thermal stress, potentially improving survival of the population and fostering adaptionary changes. Acclimation at 35 °C improved reproductive performance and population density of <em>L. trifolii</em>, particularly by enhancing the fecundity of female adults and accelerating the speed of development. Although the 40 strain exhibited the highest developmental speed and greater thermotolerance, it incurred a larger reproductive cost. This study provides a theoretical framework for monitoring and controlling leafminers and understanding their evolutionary adaptation to environmental changes.</div></div>","PeriodicalId":17428,"journal":{"name":"Journal of thermal biology","volume":"125 ","pages":"Article 103988"},"PeriodicalIF":2.9,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142375622","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The effect of incubator temperature on sex differentiation in Korat chickens was investigated. The experiments were divided into two sets: temperature applied throughout the entire incubation period and temperature applied during certain periods (days 3–6 of incubation) by either increasing above the standard or decreasing below the standard temperature. In each experiment, 300 Korat chicken eggs were separated into three groups of 5 repetitions, with 20 eggs in each group. This was done using a completely randomized design for each experiment: a group using a temperature below the standard for incubation (36.0 °C), a group using the standard incubation temperature (37.7 °C), and a group using a temperature above the standard for incubation (38.0 °C). W chromosomes were detected at hatch; histology examined reproductive structures after 35 days. Increasing the temperature to 38.0 °C throughout the entire incubation period resulted in no significant difference in hatching rates compared to the standard temperature (P > 0.05). Raising the temperature to 38.0 °C throughout the entire incubation and during certain periods resulted in changes in the reproductive structure of chickens, leading to a mismatch between chromosomal and gonadal sex, observed at 9.7% and 5.9% of individuals with W chromosomes possessed testes, indicating a mismatch between chromosomal and gonadal sex. However, decreasing the temperature to 36.0 °C throughout the incubation period resulted in lower hatching rates compared to the standard temperature (P < 0.05). Incubating eggs at 36.0 °C for specific periods resulted in 19.4% of genetic males developing ovaries instead of testes. The presence of ovaries in individuals without W chromosomes indicated this mismatch. The results of this study provide evidence that temperature plays a role in sex differentiation in Korat chickens, as demonstrated by the detection of W chromosomes and histological studies of testes and ovaries. Moreover, this study presents the first evidence in broilers that temperature can affect sex differentiation.
{"title":"Effect of egg incubator temperature on sex differentiation in Korat chickens","authors":"Chanoknan Khamoun , Sajeera Kupittayanant , Pakanit Kupittayanant","doi":"10.1016/j.jtherbio.2024.103984","DOIUrl":"10.1016/j.jtherbio.2024.103984","url":null,"abstract":"<div><div>The effect of incubator temperature on sex differentiation in Korat chickens was investigated. The experiments were divided into two sets: temperature applied throughout the entire incubation period and temperature applied during certain periods (days 3–6 of incubation) by either increasing above the standard or decreasing below the standard temperature. In each experiment, 300 Korat chicken eggs were separated into three groups of 5 repetitions, with 20 eggs in each group. This was done using a completely randomized design for each experiment: a group using a temperature below the standard for incubation (36.0 °C), a group using the standard incubation temperature (37.7 °C), and a group using a temperature above the standard for incubation (38.0 °C). W chromosomes were detected at hatch; histology examined reproductive structures after 35 days. Increasing the temperature to 38.0 °C throughout the entire incubation period resulted in no significant difference in hatching rates compared to the standard temperature (P > 0.05). Raising the temperature to 38.0 °C throughout the entire incubation and during certain periods resulted in changes in the reproductive structure of chickens, leading to a mismatch between chromosomal and gonadal sex, observed at 9.7% and 5.9% of individuals with W chromosomes possessed testes, indicating a mismatch between chromosomal and gonadal sex. However, decreasing the temperature to 36.0 °C throughout the incubation period resulted in lower hatching rates compared to the standard temperature (P < 0.05). Incubating eggs at 36.0 °C for specific periods resulted in 19.4% of genetic males developing ovaries instead of testes. The presence of ovaries in individuals without W chromosomes indicated this mismatch. The results of this study provide evidence that temperature plays a role in sex differentiation in Korat chickens, as demonstrated by the detection of W chromosomes and histological studies of testes and ovaries. Moreover, this study presents the first evidence in broilers that temperature can affect sex differentiation.</div></div>","PeriodicalId":17428,"journal":{"name":"Journal of thermal biology","volume":"125 ","pages":"Article 103984"},"PeriodicalIF":2.9,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142358132","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-01DOI: 10.1016/j.jtherbio.2024.103993
Bianca Coulson , Marc T. Freeman , Juanita Wessels , Andrew E. McKechnie
Heat loss across the beak is an important thermoregulatory mechanism among birds, particularly in large-beaked taxa such as toucans (Ramphastidae) and hornbills (Bucerotidae). The number of species investigated remains limited, as does our understanding of how the functional significance of this pathway varies with environmental variables such as humidity, with little previous research on species inhabiting humid environments. We used infrared thermography to test the hypothesis that large (600–1300 g) Afrotropical forest hornbills use their beaks and casques as thermal radiators. We collected data over air temperatures (Tair) of 15–34 °C for wild-caught trumpeter hornbills (Bycanistes bucinator) and captive-bred silvery-cheeked hornbills (Bycanistes brevis) and black-casqued hornbills (Ceratogymna atrata). Surface temperatures of the beaks and casques (Tbeak) tracked Tair below 24–25 °C, but at higher Tair, the Tbeak – Tair gradient increased to maximum values of 10–12 °C. Maximum rates of beak heat loss were 2.5–3.8 W, equivalent to 31–83 % of estimated resting metabolic heat production. Facial skin showed also evidence for active regulation of heat loss. We also analysed the scaling of the inflection Tair above which the Tbeak – Tair gradient increases (Tinflection) by combining our data with published and three unpublished values. We found that Tinflection decreases with increasing body mass (Mb), with the relationship best described by the linear regression model Tinflection = −9.134log10Mb + 50.83, with Mb in g.
{"title":"Non-evaporative heat dissipation across the beaks and casques of large forest hornbills","authors":"Bianca Coulson , Marc T. Freeman , Juanita Wessels , Andrew E. McKechnie","doi":"10.1016/j.jtherbio.2024.103993","DOIUrl":"10.1016/j.jtherbio.2024.103993","url":null,"abstract":"<div><div>Heat loss across the beak is an important thermoregulatory mechanism among birds, particularly in large-beaked taxa such as toucans (Ramphastidae) and hornbills (Bucerotidae). The number of species investigated remains limited, as does our understanding of how the functional significance of this pathway varies with environmental variables such as humidity, with little previous research on species inhabiting humid environments. We used infrared thermography to test the hypothesis that large (600–1300 g) Afrotropical forest hornbills use their beaks and casques as thermal radiators. We collected data over air temperatures (<em>T</em><sub>air</sub>) of 15–34 °C for wild-caught trumpeter hornbills (<em>Bycanistes buc</em><em>inator</em>) and captive-bred silvery-cheeked hornbills (<em>Bycanistes brevis</em>) and black-casqued hornbills (<em>Ceratogymna atrata</em>). Surface temperatures of the beaks and casques (<em>T</em><sub>beak</sub>) tracked <em>T</em><sub>air</sub> below 24–25 °C, but at higher <em>T</em><sub>air</sub>, the <em>T</em><sub>beak</sub> – <em>T</em><sub>air</sub> gradient increased to maximum values of 10–12 °C. Maximum rates of beak heat loss were 2.5–3.8 W, equivalent to 31–83 % of estimated resting metabolic heat production. Facial skin showed also evidence for active regulation of heat loss. We also analysed the scaling of the inflection <em>T</em><sub>air</sub> above which the <em>T</em><sub>beak</sub> – <em>T</em><sub>air</sub> gradient increases (<em>T</em><sub>inflection</sub>) by combining our data with published and three unpublished values. We found that <em>T</em><sub>inflection</sub> decreases with increasing body mass (<em>M</em><sub>b</sub>), with the relationship best described by the linear regression model <em>T</em><sub>inflection</sub> = −9.134log<sub>10</sub><em>M</em><sub>b</sub> + 50.83, with <em>M</em><sub>b</sub> in g.</div></div>","PeriodicalId":17428,"journal":{"name":"Journal of thermal biology","volume":"125 ","pages":"Article 103993"},"PeriodicalIF":2.9,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142468719","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-01DOI: 10.1016/j.jtherbio.2024.103987
Erin K. Francispillai, Sixtine M. Dietsch, Lauren J. Chapman
Deforestation can increase light penetration and runoff entering adjacent freshwaters leading to increased average water temperature, stronger diel temperature fluctuations, and increased water turbidity. Changes in temperature extremes (particularly upper peaks) are important for fishes as their body temperature and rate of oxygen consumption varies with environmental temperature. Here, we compare effects of diel-fluctuating versus stable water temperature regimes on the behaviour and upper thermal tolerance (measured as Critical Thermal Maximum, CTmax) of the Bluntnose Minnow, Pimephales notatus. Fish were acclimated to either a static 18°C, static 24°C or a diel-fluctuating treatment of low to high (18-24°C) for a total of 10 weeks. Activity level and aggression were measured for 6 consecutive weeks during the acclimation period. Activity level remained high across treatments and over time. However, fish from the diel-fluctuating treatment exhibited a significant increase in aggression over the day as temperatures increased from 18°C to 24°C. Following acclimation, upper thermal limits of fish from each treatment were measured under two conditions: clear water (<2 NTU) and turbid water (25 NTU). This was to evaluate effects of acute turbidity exposure that might arise with heavy rain on deforested streams. CTmax was lowest in fish acclimated to static 18°C and highest in fish acclimated to static 24°C; fish acclimated to diel 18-24°C showed an intermediate CTmax. Exposure to acute turbidity during CTmax trials significantly lowered CTmax across all treatments, highlighting the importance of multiple-stressor studies in evaluating upper thermal tolerance of fishes.
{"title":"Effects of temperature on fish aggression and the combined impact of temperature and turbidity on thermal tolerance","authors":"Erin K. Francispillai, Sixtine M. Dietsch, Lauren J. Chapman","doi":"10.1016/j.jtherbio.2024.103987","DOIUrl":"10.1016/j.jtherbio.2024.103987","url":null,"abstract":"<div><div>Deforestation can increase light penetration and runoff entering adjacent freshwaters leading to increased average water temperature, stronger diel temperature fluctuations, and increased water turbidity. Changes in temperature extremes (particularly upper peaks) are important for fishes as their body temperature and rate of oxygen consumption varies with environmental temperature. Here, we compare effects of diel-fluctuating versus stable water temperature regimes on the behaviour and upper thermal tolerance (measured as Critical Thermal Maximum, CT<sub>max</sub>) of the Bluntnose Minnow, <em>Pimephales notatus</em>. Fish were acclimated to either a static 18°C, static 24°C or a diel-fluctuating treatment of low to high (18-24°C) for a total of 10 weeks. Activity level and aggression were measured for 6 consecutive weeks during the acclimation period. Activity level remained high across treatments and over time. However, fish from the diel-fluctuating treatment exhibited a significant increase in aggression over the day as temperatures increased from 18°C to 24°C. Following acclimation, upper thermal limits of fish from each treatment were measured under two conditions: clear water (<2 NTU) and turbid water (25 NTU). This was to evaluate effects of acute turbidity exposure that might arise with heavy rain on deforested streams. CT<sub>max</sub> was lowest in fish acclimated to static 18°C and highest in fish acclimated to static 24°C; fish acclimated to diel 18-24°C showed an intermediate CT<sub>max</sub>. Exposure to acute turbidity during CT<sub>max</sub> trials significantly lowered CT<sub>max</sub> across all treatments, highlighting the importance of multiple-stressor studies in evaluating upper thermal tolerance of fishes.</div></div>","PeriodicalId":17428,"journal":{"name":"Journal of thermal biology","volume":"125 ","pages":"Article 103987"},"PeriodicalIF":2.9,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142423327","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-01DOI: 10.1016/j.jtherbio.2024.103977
Julián Cabello-Vergel , Jorge S. Gutiérrez , Erick González-Medina , Juan M. Sánchez-Guzmán , José A. Masero , Auxiliadora Villegas
Discrete populations of widely distributed species may inhabit areas with marked differences in climatic conditions across geographic and seasonal scales, which could result in intraspecific variation in thermal physiology reflecting genetic adaptation, phenotypic plasticity, or both. However, few studies have evaluated inter-population variation in physiological responses to heat. We evaluated within- and inter-population seasonal variation in heat tolerance, cooling efficiency and other key thermoregulatory traits in two Mediterranean populations of Great tit Parus major experiencing contrasting thermal environments: a lowland population subject to hotter summers and a higher annual thermal amplitude than a montane population. Specifically, we measured heat tolerance limits (HTL), body temperature, resting metabolic rate, evaporative water loss, and evaporative cooling efficiency (the ratio between evaporative heat loss to metabolic heat production) within and above the thermoneutral zone during winter and summer. Heat tolerance during summer was greater in lowland than in montane birds; indeed, lowland birds seasonally increased this trait to a significant level, while montane ones did to a lesser extent. Besides, lowland birds showed greater evaporative cooling efficiency during summer (possibly due in part to reductions in total endogenous heat load), while surprisingly montane ones showed the opposite trend. Thus, lowland birds displayed greater seasonal flexibility in HTL, body temperature and resting metabolic rate above thermoneutrality, thus giving some support to the climatic variability hypothesis — that flexibility in thermoregulatory traits should increase with climatic variability. Our results partially support the idea that songbirds’ adaptive thermoregulation in the heat is flexible, highlighting the importance of considering intraspecific variation in thermoregulatory traits when modelling the future distribution and persistence of species under different climate change scenarios.
{"title":"Seasonal and between-population variation in heat tolerance and cooling efficiency in a Mediterranean songbird","authors":"Julián Cabello-Vergel , Jorge S. Gutiérrez , Erick González-Medina , Juan M. Sánchez-Guzmán , José A. Masero , Auxiliadora Villegas","doi":"10.1016/j.jtherbio.2024.103977","DOIUrl":"10.1016/j.jtherbio.2024.103977","url":null,"abstract":"<div><div>Discrete populations of widely distributed species may inhabit areas with marked differences in climatic conditions across geographic and seasonal scales, which could result in intraspecific variation in thermal physiology reflecting genetic adaptation, phenotypic plasticity, or both. However, few studies have evaluated inter-population variation in physiological responses to heat. We evaluated within- and inter-population seasonal variation in heat tolerance, cooling efficiency and other key thermoregulatory traits in two Mediterranean populations of Great tit <em>Parus major</em> experiencing contrasting thermal environments: a lowland population subject to hotter summers and a higher annual thermal amplitude than a montane population. Specifically, we measured heat tolerance limits (HTL), body temperature, resting metabolic rate, evaporative water loss, and evaporative cooling efficiency (the ratio between evaporative heat loss to metabolic heat production) within and above the thermoneutral zone during winter and summer. Heat tolerance during summer was greater in lowland than in montane birds; indeed, lowland birds seasonally increased this trait to a significant level, while montane ones did to a lesser extent. Besides, lowland birds showed greater evaporative cooling efficiency during summer (possibly due in part to reductions in total endogenous heat load), while surprisingly montane ones showed the opposite trend. Thus, lowland birds displayed greater seasonal flexibility in HTL, body temperature and resting metabolic rate above thermoneutrality, thus giving some support to the climatic variability hypothesis — that flexibility in thermoregulatory traits should increase with climatic variability. Our results partially support the idea that songbirds’ adaptive thermoregulation in the heat is flexible, highlighting the importance of considering intraspecific variation in thermoregulatory traits when modelling the future distribution and persistence of species under different climate change scenarios.</div></div>","PeriodicalId":17428,"journal":{"name":"Journal of thermal biology","volume":"125 ","pages":"Article 103977"},"PeriodicalIF":2.9,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142358175","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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