Predicted effects of anthropogenic climate change on estuarine and coastal organisms are complex, and early life history stages of calcified ectotherms are amongst the most sensitive groups. Despite the importance of understanding their vulnerability, we lack information on the effects of multiple stressors on the embryonic development of estuarine and burrowing organisms, mainly mangrove-associated species. Here, we determined the combined effects of elevated temperature and decreased pH on the embryonic development of the estuarine fiddler crab . Initially, the microhabitat (burrow) of ovigerous (egg-bearing) females was measured for temperature, pH, and salinity, which provided control values in our laboratory experiment. Embryos at the early stage of development were subjected to cross-factored treatments of predicted temperature and pH and evaluated for development rate, survivorship, and volume until their later embryonic stage. Embryo development was faster at early and later stages of development, and survivorship was lower under elevated temperature. Embryos under reduced pH showed advanced embryonic stages at their late development stage. Higher egg volume was observed in a warmer and acidified environment, and lower volume in warmer and non-acidified conditions, indicating that embryo development is synergistically affected by warming and acidification. More than 70% of embryos developed until late stages under the multiple-stressors treatment, giving insights on the effects of a warm and acidified environment on burrowing estuarine organisms and their early stages of development.

中文翻译：

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变暖和酸化对河口招潮蟹胚胎发育的多重应激影响

人为气候变化对河口和沿海生物的预测影响是复杂的，钙化变温动物的早期生活史阶段是最敏感的群体之一。尽管了解它们的脆弱性很重要，但我们缺乏关于多种压力因素对河口和穴居生物（主要是红树林相关物种）胚胎发育影响的信息。在这里，我们确定了温度升高和 pH 值降低对河口招潮蟹胚胎发育的综合影响。最初，测量了产卵（产卵）雌性的微生境（洞穴）的温度、pH 值和盐度，这为我们的实验室实验提供了控制值。对发育早期的胚胎进行预测温度和 pH 值的交叉因素处理，并评估发育率、存活率和体积，直到胚胎后期。胚胎在发育早期和后期发育更快，在高温下存活率更低。pH 值降低的胚胎在发育后期表现出较高的胚胎阶段。在较温暖和酸化的环境中观察到较高的卵体积，在较温暖和非酸化的条件下观察到较低的体积，这表明胚胎发育受到变暖和酸化的协同影响。在多重应激源处理下，超过 70% 的胚胎发育至晚期，这让我们深入了解温暖和酸化的环境对穴居河口生物及其早期发育阶段的影响。