Active prey rejection in the filter-feeding appendicularian Oikopleura dioica
Active prey rejection in the filter-feeding appendicularian Oikopleura dioica
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DOI：
10.4319/lo.2011.56.4.1504
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发表时间：
2011-07-01
影响因子：
4.5
通讯作者：
Kiorboe, T.
中科院分区：
文献类型：
--
作者：
Lombard, F.;Selander, E.;Kiorboe, T.
我们描述了不同的模式的猎物拒绝在滤食性的apapellularian，Oikopleura dioica。非选择性的猎物排斥发生在咽部过滤器过载时，通过所有颗粒的摄食电流的逆转而发生的间歇性排斥，以及当咽部过滤器偶尔破裂时，通过所有进入房屋的颗粒的气孔而发生的意外损失。此外，通过呼吸孔中纤毛电流的逆转，可以在口中发生对单个颗粒的选择性猎物排斥：用少量的水排出不需要的颗粒。每秒最多可发生四次单个粒子的排斥。这种主动截留是基于单个颗粒的尺寸和化学特性。一个显着较高的拒绝率被发现为有毒的甲藻（68%）相比，类似大小的无毒的（34%）;指数增长的藻类被拒绝比衰老的;和营养耗尽的藻类被拒绝比营养丰富的细胞。对于无毒颗粒，相对于浮游动物大小的猎物大小是主要的猎物选择标准，也是O. dioica的颗粒大小在其自身大小的0.4%至2%之间，而它们可以摄取的最小和最大颗粒大小在其自身大小的0.04%至20%之间。这猎物的大小谱是更广泛的，比大多数其他的食虫生物，并表明apapericularians同时microphagous和macrophagous的食草动物。
We describe different modes of prey rejection in a filter-feeding appendicularian, Oikopleura dioica. Nonselective prey rejection occurs by intermittent rejection through reversal of the feeding current of all particles when the pharyngeal filter is overloaded, and by accidental loss through the spiracles of all particles that have entered the house when the pharyngeal filter occasionally breaks. In addition, selective prey rejection of individual particles may occur in the mouth by reversal of the ciliary current in the spiracle: the unwanted particle is expelled with a small amount of water. Up to four rejections of individual particles may occur per second. This active rejection is based on both the size and the chemical characteristics of the individual particle. A significantly higher rejection rate was found for toxic dinoflagelate (68%) compared to similar sized nontoxic ones (34%); exponentially growing algae were less rejected than senescent ones; and nutrient-depleted algae were more rejected than nutrient-replete cells. For nontoxic particles, prey size relative to the size of the appendicularian was the main prey selection criterion and the optimal prey size (> 80% acceptance) for O. dioica is between 0.4% and 2% of their own size, whereas the minimum and maximum particle sizes that they can ingest range from 0.04% to 20% of their own size. This prey size spectrum is much broader than that found in most other planktivorous organisms and demonstrates that appendicularians are simultaneous microphageous and macrophageous planktonic grazers.