Leptocephalus larvae have transparent bodies with tubular intestines that usually lack identifiable food items when they are collected, so mystery has surrounded efforts to determine what they feed on. Artificially spawned and reared first-feeding larvae were found to be highly selective in what they would eat, but they would consume rotifers and eventually ate specially formulated diets that contained shark egg yolk. Gut content studies on wild-caught leptocephali in the Atlantic and Pacific observed marine snow-associated materials such as discarded appendicularian houses, zooplankton fecal pellets, protists, and amorphous materials, and DNA sequencing indicated that the gut contents contain materials originating from a wide range of microorganisms and food web zooplankton species that were likely consumed in marine snow. Isotopic studies found a low trophic position of leptocephali and inter-taxa and geographic signature differences. Behavioral studies with leptocephali and the characteristics and size-scaling of the teeth are also consistent with feeding on marine snow-related particles. The feeding strategy of leptocephali appears to be based on consuming types of marine snow that contain nutritious and easily assimilated carbohydrates, fatty acids, and other materials that facilitate rapid conversion to glycosaminoglycans and tissues for energy storage and growth.

中文翻译：

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小头鱼神秘的摄食生态：一种独特的消耗海洋雪料的策略

Leptocephalus 幼虫具有透明的身体和管状肠，在收集时通常缺乏可识别的食物，因此确定它们以什么为食的努力一直是个谜。人工产卵和饲养的第一次进食的幼虫被发现对它们吃的东西具有高度选择性，但它们会吃轮虫并最终吃含有鲨鱼蛋黄的特殊配方的饮食。对大西洋和太平洋野生捕捞的钩端动物的肠道内容研究观察到海洋积雪相关材料，例如废弃的附肢房屋、浮游动物粪便颗粒、原生生物和无定形材料，DNA 测序表明肠道内容物包含来自广泛范围的材料可能在海洋雪中消耗的微生物和食物网浮游动物物种的数量。同位素研究发现细头动物的低营养位置、分类群间和地理特征差异。对细头虫的行为研究以及牙齿的特征和大小比例也与以海洋雪相关的颗粒为食是一致的。leptocephali 的饲养策略似乎是基于消耗类型的海洋雪，这些海洋雪含有营养丰富且易于吸收的碳水化合物、脂肪酸和其他材料，这些材料有助于快速转化为糖胺聚糖和组织以进行能量储存和生长。