Western Baltic spring spawning herring ( L) is a commercially important fish stock currently suffering a strong decline. Larval survival is essential for stock recruitment and can be substantially decreased by predation. The comb jelly A. Agassiz, 1865, is a lobate ctenophore which is invasive to the Baltic Sea and a known ichthyoplankton predator. However, predation on herring larvae in the Baltic Sea by has not been studied since its initial establishment in 2006. To address this knowledge gap, we conducted feeding experiments to investigate (1) the predation capability of on herring yolk-sac larvae, and (2) the influence of larval age, (3) predator size and (4) the presence of alternative prey on the clearance rate of on herring yolk-sac larvae. Our results showed that exhibited the ability to capture and digest herring larvae. The clearance rates of on herring larvae decreased with larval age and increased with predator size, while the presence of alternative prey had no effect on clearance rates. This finding suggests that can efficiently consume herring yolk-sac larvae under laboratory conditions. However, further investigations using mesocosm or field studies are necessary to evaluate the potential impact of on the mortality and recruitment of herring yolk-sac larvae under Baltic Sea field conditions.

中文翻译：

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入侵性栉水母 Mnemiopsis leidyi 对波罗的海卵黄囊鲱鱼幼虫 (Clupea harengus) 的捕食

西波罗的海春季产卵鲱鱼 (L) 是一种重要的商业鱼类资源，目前正遭受严重下降。幼虫的存活率对于种群补充至关重要，并且会因捕食而大大降低。栉水母 A. Agassiz，1865 年，是一种叶状栉水母，入侵波罗的海，是已知的浮游鱼类捕食者。然而，自 2006 年首次建立以来，波罗的海对鲱鱼幼虫的捕食尚未进行过研究。为了解决这一知识空白，我们进行了摄食实验来调查（1）对鲱鱼卵黄囊幼虫的捕食能力，以及（ 2) 幼虫年龄、(3) 捕食者大小和 (4) 替代猎物的存在对鲱鱼卵黄囊幼虫清除率的影响。我们的结果表明，它具有捕获和消化鲱鱼幼虫的能力。鲱鱼幼虫的清除率随着幼虫年龄的增长而降低，并随着捕食者的大小而增加，而替代猎物的存在对清除率没有影响。这一发现表明在实验室条件下可以有效地消耗鲱鱼卵黄囊幼虫。然而，有必要使用中生态系统或实地研究进行进一步调查，以评估波罗的海野外条件下对鲱鱼卵黄囊幼虫死亡率和补充的潜在影响。