Degradation of discarded appendicularian houses by oncaeid copepods
Degradation of discarded appendicularian houses by oncaeid copepods
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DOI：
10.1002/lno.10061
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发表时间：
2015-05
影响因子：
4.5
通讯作者：
Y. Nishibe;Kazutaka Takahashi;T. Ichikawa;K. Hidaka;H. Kurogi;K. Segawa;H. Saito
中科院分区：
文献类型：
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作者：
Y. Nishibe;Kazutaka Takahashi;T. Ichikawa;K. Hidaka;H. Kurogi;K. Segawa;H. Saito
我们检查了由于黑潮地区地表水中的桡足类动物进食而废弃的阑尾房屋的退化情况。使用视频浮游生物记录仪（VPR）通过光学采样研究了Oncaeid桡足类和废弃房屋的垂直分布。原位 VPR 观测表明，oncaeid 桡足类通常与废弃房屋相关：在房屋浓度超过 2000 m−3 时，附着在废弃房屋上的个体比例达到 25‐39% 的饱和值，这表明 oncaeid 桡足类的摄食不受通常在 50 m 以上的房屋浓度中观察到的遭遇的限制。实验室观察证实，Oncaeid桡足类附着在废弃房屋的表面并摄入房屋膜和粘附颗粒。通过测量粪便颗粒产生和同化效率确定，主要 Oncaea 物种 O. venusta 和 O. media 的个体摄食率从 0.13 μg C ind.−1 d−1 到 1.3 μg C ind.−1 d−1 （10‐37% 身体 C d−1）不等。我们的结果表明，Oncaeid桡足类群落每天在水柱上部100 m消耗多达10%的房屋生物量，并表明通过它们与废弃的阑尾房屋的紧密营养耦合，oncaeids对地表水中的房屋退化做出了重大贡献。
We examined the degradation of discarded appendicularian houses due to feeding by oncaeid copepods in surface waters of the Kuroshio region. Vertical distributions of oncaeid copepods and discarded houses were investigated by optical sampling using a video plankton recorder (VPR). In situ VPR observations revealed that oncaeid copepods were commonly associated with discarded houses: the proportion of individuals attached to discarded houses reached saturated values of 25‐39% at house concentrations above 2000 houses m−3, suggesting that feeding by oncaeids was not limited by encounters at house concentrations typically observed in the upper 50 m. Laboratory observations confirmed that oncaeid copepods attached to the surface of discarded houses and ingested both house membranes and adhering particles. Individual feeding rates of the dominant Oncaea species, O. venusta and O. media, determined by measuring fecal pellet production and assimilation efficiency, varied from 0.13 μg C ind.−1 d−1 to 1.3 μg C ind.−1 d−1 (10‐37% body C d−1). Our results indicate that the oncaeid copepod community consumed up to 10% of house biomass each day in the upper 100 m of the water column, and show that through their close trophic coupling with discarded appendicularian houses, the oncaeids contribute significantly to house degradation in surface waters.