Temperature fluctuations and climate change impacts may substantially affect spawning success of fish, especially migratory species with a limited spawning window. Factors affecting American shad (Alosa sapidissima) spawning success and survival were investigated at different temperatures and periods (peak- and late-spawning periods) during the Connecticut River, USA, spawning migration in 2017. Wild caught American shad were exposed to constant temperatures regimes of 15, 18, 21, 24 and 27 °C for 2 weeks. During the peak-spawning period, an increase in temperature (15–24 °C) was shown to increase spawning success factors, including spawning probability, number of eggs, and fertilization success, but decreased egg size. Temperatures between 18 and 27 °C did not affect these factors during the late-spawning period. Glochidia infection by the alewife floater (Anodonta implicata) was much higher in the late-spawning period and significantly decreased the survival of American shad. Further research should investigate the parasite-host relationship between the alewife floater and American shad to determine annual variability of glochidia infections and how they affect American shad from physiological and passage perspectives. Higher temperatures were shown to increase spawning success of American shad during the peak-spawning period, but temperature had no effect during the late-spawning period. However, any effect during the late-spawning period may have been masked by a high level of glochidia infection.

温度波动和气候变化影响可能会严重影响鱼类的产卵成功率，尤其是产卵窗口有限的洄游物种。影响美洲鲱（Alosa sapidissima ）的因素) 在美国康涅狄格河的不同温度和时期（产卵高峰期和后期产卵期）调查了产卵成功率和存活率，2017 年产卵迁徙。野生捕获的美洲鲱暴露于 15、18、21、 24 和 27 °C 持续 2 周。在产卵高峰期，温度升高（15-24°C）显示会增加产卵成功因素，包括产卵概率、卵数和受精成功率，但会降低卵的大小。在产卵后期，18 至 27 °C 之间的温度不会影响这些因素。飞蚊 ( Anodonta implica ) 感染 Glochidia) 在产卵后期要高得多，并且显着降低了美洲鲱的存活率。进一步的研究应该调查 alewife floater 和美洲鲱之间的寄生虫 - 宿主关系，以确定 glochidia 感染的年度变异性以及它们如何从生理和通道角度影响美洲鲱。较高的温度被证明可以增加美洲鲱在产卵高峰期的产卵成功率，但在产卵后期温度没有影响。然而，在后期产卵期间的任何影响都可能被高水平的 glochidia 感染所掩盖。