Nocturnal migration reduces exposure to micropredation in a coral reef fish
Nocturnal migration reduces exposure to micropredation in a coral reef fish
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夜间迁徙减少了珊瑚礁鱼遭受微捕食的机会
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发表时间：
2017
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影响因子：
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通讯作者：
Joseph C. Sellers
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作者：
P. Sikkel;R. Welicky;J. Artim;A. McCammon;Joseph C. Sellers
热带大西洋的海鲶科鱼类（海鲶科）白天在珊瑚礁上保持静止，晚上迁移到海草床或沙滩上。这种夜间迁徙的假设优势是增加食物供应和/或降低捕食风险。在这里，我们测试了另一种假设的预测，夜间迁移的法国咕噜，Haemulon flavolineatum（Desmarest，1823年），减少暴露于吸血的颚类等足类动物。石鲈离开珊瑚礁的同时，颚类动物的活动也在增加。在野外实验中，亚成鱼放在笼子里，部署在珊瑚礁上，在晚上窝藏显着更多的gnathiids比那些放在海草栖息地。然而，这是不是在白天的情况下，在所有栖息地的颚活动是低的。在另一个实验中，返回珊瑚礁的时间被确定为与黎明后颚类动物活动减少的时间相一致。在两个地点的累积gnathiid暴露的估计显示，晚上留在珊瑚礁栖息地的咕噜声将经历平均3和44倍的gnathiids比如果他们在海草床过夜，并可以达到300多gnathiids在一条鱼。在最后的野外实验中，即使是最近定居（<2厘米）的幼鱼也会受到颚类动物的侵扰，这支持了之前的实验室实验，即一个第三阶段的颚类动物会侵扰并杀死这种大小的咕噜鱼。结合起来，这些研究结果表明，法国咕噜鱼和生态相似的鱼类的夜间觅食迁移导致减少暴露于吸血的颚类等足类动物。
Tropical Atlantic reef fishes in the family Haemulidae (grunts) remain quiescent on reefs during the day and migrate to seagrass beds or sand flats at night. Hypothesized advantages of such nocturnal migrations are increased food availability and/or decreased predation risk. Here, we tested predictions of an alternative hypothesis that nocturnal migrations of French grunt, Haemulon flavolineatum (Desmarest, 1823), reduce exposure to blood-feeding gnathiid isopods. The departure of grunts from the reef coincides with increasing gnathiid activity. In field experiments, subadult fish placed in cages and deployed on the reef at night harbored significantly more gnathiids than those placed in the seagrass habitat. However, this was not the case during the day when gnathiid activity in all habitats is low. In another experiment, the timing of return to the reef was determined to coincide with the postdawn decrease in gnathiid activity. Estimates of cumulative gnathiid exposure at two sites revealed that grunts remaining in reef habitat at night would experience an average of 3 and 44 times more gnathiids than if they spent the night in the seagrass bed, and could reach more than 300 gnathiids on a single fish. In a final field experiment, even recently-settled (<2 cm) juvenile grunts were infested by gnathiids, supporting previous laboratory experiments showing that a single third-stage gnathiid will infest and kill grunts of this size. Combined, these findings suggest that nocturnal feeding migrations of French grunts and ecologically similar fishes result in reduced exposure to blood-feeding gnathiid isopods.