{"title":"Heatwaves during embryonic development reveal duration-dependent effects in zebrafish","authors":"Náyade Álvarez-Quintero , Livia Pinzoni , Merel C. Breedveld , Clelia Gasparini","doi":"10.1016/j.jtherbio.2025.104195","DOIUrl":null,"url":null,"abstract":"<div><div>Heatwaves, defined as periods of unusually high temperatures are increasingly frequent due to climate change. It is well known that ectotherms are particularly vulnerable to heat stress, especially during sensitive life stages such as embryonic development. However, the consequences of short, ecologically relevant heat stress, remain less investigated. Here, we investigate the effects of short-term heat stress during embryonic development in zebrafish (<em>Danio rerio</em>). For this, 1753 embryos were exposed to simulated heatwaves of different durations (6, 24, or 48 h) and frequencies (one or two events) during development, with a temperature of 35 °C (+7 °C above the standard temperature of 28 °C). Their pre- and post-natal survival, hatching time, larval body size, and locomotor activity once hatched were evaluated. Additionally, the larval locomotor activity was assessed at control and heat-stress temperatures to determine if embryonic heat stress would result in larvae coping better with high temperatures. Our results showed that exposure to high temperatures (35 °C) increased pre-natal mortality, and further effects varied depending on the duration of the heatwave. Longer heatwaves (48 h) accelerated the rate of development but resulted in smaller larvae that swam more under heat stress, while short heatwaves (24 h and two repeated periods of 6 h) did not have any effect. Our results indicate that the embryonic stage is highly sensitive to even brief periods of heat stress, such as those experienced during a heatwave, and that the duration of exposure leads to different responses. These findings offer crucial insights into the extreme sensitivity of embryos to heatwaves and highlight wider consequences for individuals and populations, which are crucial for predicting how species will respond to ongoing climate change.</div></div>","PeriodicalId":17428,"journal":{"name":"Journal of thermal biology","volume":"131 ","pages":"Article 104195"},"PeriodicalIF":2.9000,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of thermal biology","FirstCategoryId":"99","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0306456525001524","RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"BIOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Heatwaves, defined as periods of unusually high temperatures are increasingly frequent due to climate change. It is well known that ectotherms are particularly vulnerable to heat stress, especially during sensitive life stages such as embryonic development. However, the consequences of short, ecologically relevant heat stress, remain less investigated. Here, we investigate the effects of short-term heat stress during embryonic development in zebrafish (Danio rerio). For this, 1753 embryos were exposed to simulated heatwaves of different durations (6, 24, or 48 h) and frequencies (one or two events) during development, with a temperature of 35 °C (+7 °C above the standard temperature of 28 °C). Their pre- and post-natal survival, hatching time, larval body size, and locomotor activity once hatched were evaluated. Additionally, the larval locomotor activity was assessed at control and heat-stress temperatures to determine if embryonic heat stress would result in larvae coping better with high temperatures. Our results showed that exposure to high temperatures (35 °C) increased pre-natal mortality, and further effects varied depending on the duration of the heatwave. Longer heatwaves (48 h) accelerated the rate of development but resulted in smaller larvae that swam more under heat stress, while short heatwaves (24 h and two repeated periods of 6 h) did not have any effect. Our results indicate that the embryonic stage is highly sensitive to even brief periods of heat stress, such as those experienced during a heatwave, and that the duration of exposure leads to different responses. These findings offer crucial insights into the extreme sensitivity of embryos to heatwaves and highlight wider consequences for individuals and populations, which are crucial for predicting how species will respond to ongoing climate change.
期刊介绍:
The Journal of Thermal Biology publishes articles that advance our knowledge on the ways and mechanisms through which temperature affects man and animals. This includes studies of their responses to these effects and on the ecological consequences. Directly relevant to this theme are:
• The mechanisms of thermal limitation, heat and cold injury, and the resistance of organisms to extremes of temperature
• The mechanisms involved in acclimation, acclimatization and evolutionary adaptation to temperature
• Mechanisms underlying the patterns of hibernation, torpor, dormancy, aestivation and diapause
• Effects of temperature on reproduction and development, growth, ageing and life-span
• Studies on modelling heat transfer between organisms and their environment
• The contributions of temperature to effects of climate change on animal species and man
• Studies of conservation biology and physiology related to temperature
• Behavioural and physiological regulation of body temperature including its pathophysiology and fever
• Medical applications of hypo- and hyperthermia
Article types:
• Original articles
• Review articles