The mysid Neomysis americana (Smith, 1873) is native to shallow shelf waters and estuaries of the western Atlantic coast of North America. Despite the important role mysids such as N. americana play in estuarine ecosystems as both consumers and as prey for higher trophic levels, there is limited information on how metabolism influences their spatial ecology and habitat requirements. In tributaries of Chesapeake Bay, MD, USA, previous research has shown that summer water temperatures can approach the lethal upper tolerance limit for N. americana. We measured the per capita metabolic rate (µgO₂ min^–1) of N. americana from the upper Patuxent River near Benedict, MD, a tributary of Chesapeake Bay in the laboratory to evaluate the metabolic response to salinity and temperature conditions that mysids experience in natural habitats. Sex-specific and diel patterns in metabolic rate were quantified. Metabolic rates did not differ between night and day and there was no significant difference in metabolic rate between males and females, exclusive of gravid females. Metabolic rates were lowest in salinity treatments of 2 and 8 at 29 °C, and highest in the salinity 2 treatment at 22 °C. Only temperature had a statistically significant, albeit unexpected, effect. This study shows that the metabolic response of N. americana to temperature and salinity conditions is complex and plastic, and that metabolic rates can vary 3–4 fold within realistic summer temperature and salinity conditions. As environmental conditions continue to change, understanding metabolic response of mysids to realistic salinity and temperature conditions is necessary for understanding their distributions in temperate estuaries.

中文翻译：

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温带河口的美洲Neomysis americana（Smith，1873）（Mysida：Mysidae）的代谢率随夏季温度和盐度条件的变化而变化

Mysid American Neomysis americana（史密斯，1873年）原产于北美西部大西洋沿岸浅水区和河口。尽管诸如美国猪笼草之类的类象素在河口生态系统中既扮演着消费者的角色，又是更高营养级别的猎物，但它们对新陈代谢如何影响其空间生态和栖息地需求的信息仍然有限。在美国马里兰州切萨皮克湾的支流中，先前的研究表明，夏季水温可能接近美国猪笼草的致死上限。我们测量了美国猪笼草的人均代谢率（µgO ₂ min ^–1）来自马里兰州本尼迪克特市附近的Patuxent河上游，该实验室是切萨皮克湾的支流，用于评估my类在自然栖息地中经历的盐度和温度条件的代谢反应。定量分析代谢率的性别特异性和迪尔模式。白天和黑夜之间的代谢率没有差异，并且男性和女性（妊娠女性除外）的代谢率没有显着差异。在29°C下，盐度2和8处理的代谢率最低，在22°C下，盐度2处理的代谢率最高。尽管有意想不到的影响，但只有温度具有统计学上的显着影响。这项研究表明美洲猪笼草的代谢反应温度和盐度条件的复杂性和可塑性，在现实的夏季温度和盐度条件下，新陈代谢率可以变化3-4倍。随着环境条件的不断变化，了解类固醇对实际盐度和温度条件的代谢反应对于了解它们在温带河口的分布非常必要。