Active prey selection in developing larvae of Atlantic bluefin tuna ( Thunnus thynnus ) in spawning grounds of the Gulf of Mexico
Active prey selection in developing larvae of Atlantic bluefin tuna ( Thunnus thynnus ) in spawning grounds of the Gulf of Mexico
复制标题
墨西哥湾产卵场大西洋蓝鳍金枪鱼幼体发育中的主动猎物选择
DOI：
10.1093/plankt/fbab020
复制
发表时间：
2021
影响因子：
2.1
通讯作者：
Dolan, ed., John
中科院分区：
文献类型：
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作者：
Shiroza, Akihiro;Malca, Estrella;Lamkin, John T.;Gerard, Trika;Landry, Michael R.;Stukel, Michael R.;Laiz-Carrión, Raúl;Swalethorp, Rasmus;Dolan, ed., John
蓝鳍金枪鱼在亚热带贫营养海域的限制区域产卵。在这里，我们调查的浮游动物的猎物和摄食选择性的早期幼虫阶段的大西洋蓝鳍金枪鱼（ABT，Thunnus thynnus）在幼虫饲养栖息地的墨西哥湾。在2017年5月和2018年5月产卵高峰期的两次多日拉格朗日实验中收集了幼虫和浮游动物。根据屈曲阶段和标准长度对喉进行分类。我们确定，列举和大小浮游动物幼虫肠道内容物和周围社区。纤毛虫是定量的重要（高达9%），在碳基饲料的早期幼虫。随着幼虫的生长，饮食组成和猎物的选择从小型桡足类无节幼体和哲水蚤桡足类转移到较大的足类枝角类，占70%的摄入碳。即使在枝角类丰度小于0.2 m−3时，它们也占屈曲后阶段食物的23%。不同发育阶段幼虫的摄食行为更加专业化，当这些类群更丰富时，猎物选择范围缩小到无尾目和主要的枝角类。我们的研究结果表明，ABT幼虫有能力从被动的选择，调节物理因素，主动选择可能精力充沛的最佳猎物。
Bluefin tuna spawn in restricted areas of subtropical oligotrophic seas. Here, we investigate the zooplankton prey and feeding selectivity of early larval stages of Atlantic bluefin tuna (ABT,Thunnus thynnus) in larval rearing habitat of the Gulf of Mexico. Larvae and zooplankton were collected during two multi-day Lagrangian experiments during peak spawning in May 2017 and 2018. Larvae were categorized by flexion stage and standard length. We identified, enumerated and sized zooplankton from larval gut contents and in the ambient community. Ciliates were quantitatively important (up to 9%) in carbon-based diets of early larvae. As larvae grew, diet composition and prey selection shifted from small copepod nauplii and calanoid copepodites to larger podonid cladocerans, which accounted for up to 70% of ingested carbon. Even when cladoceran abundances were <0.2 m−3, they comprised 23% of postflexion stage diet. Feeding behaviors of larvae at different development stages were more specialized, and prey selection narrowed to appendicularians and primarily cladocerans when these taxa were more abundant. Our findings suggest that ABT larvae have the capacity to switch from passive selection, regulated by physical factors, to active selection of presumably energetically optimal prey.