High prey-predator size ratios and unselective feeding in copepods: A seasonal comparison of five species with contrasting feeding modes
High prey-predator size ratios and unselective feeding in copepods: A seasonal comparison of five species with contrasting feeding modes
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DOI：
10.1016/j.pocean.2018.04.013
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发表时间：
2018-07-01
影响因子：
4.1
通讯作者：
Mayor, Daniel J.
中科院分区：
文献类型：
--
作者：
Djeghri, Nicolas;Atkinson, Angus;Mayor, Daniel J.
人们对基于特征的浮游动物方法的兴趣激增，对浮游动物摄食模式与浮游植物特征（如大小或运动）的季节性变化进行建模。我们在普利茅斯以南的两个英吉利海峡浮游生物监测站（L4和El）研究了这种联系。在L4有一个一般的过渡，从硅藻在春季到能动的浮游生物在夏季和秋季，但这并没有反映在桡足类的摄食特征的继承，例如伏击Oithona similis占主导地位的春季硅藻水华。在附近的El，我们测量了食物和食草动物的季节性，发现2014年和2015年之间的变化很大，但总体上中等浮游动物生物量较低（中位数为4.5 mg C m（-3））。我们还做了一个季节性放牧研究的5种桡足类（Calculus helgolandicus，Centropages typicus，Acartia clausi，Pseudocalanus elongatus和Oithona similis）的对比喂养模式，计算较大的猎物项目从自然悬浮物。所有种类的桡足类动物喂养的所有食物类型和它们的饮食之间的差异只是微妙的，压倒一切的驱动程序的饮食是猎物场的组成。即使是较小的桡足类饲料桡足类无节幼体在显着的利率，支持以前的建议，公会内捕食的重要性。所有桡足类，包括O. similis能够以与纤毛虫相当的清除率处理极长（> 500 μ m）的硅藻链。最大观测猎物：捕食者长度比范围为0.12（C。helgolandicus）最高达0.52（O. similis）。非选择性的摄食行为和去除高度细长细胞的能力对桡足类摄食在生态和生物地球化学模型中的代表性有影响。
There has been an upsurge of interest in trait-based approaches to zooplankton, modelling the seasonal changes in the feeding modes of zooplankton in relation to phytoplankton traits such as size or motility. We examined this link at two English Channel plankton monitoring sites south of Plymouth (L4 and El). At L4 there was a general transition from diatoms in spring to motile microplankton in summer and autumn, but this was not mirrored in the succession of copepod feeding traits; for example the ambushing Oithona similis dominated during the spring diatom bloom. At nearby El we measured seasonality of food and grazers, finding strong variation between 2014 and 2015 but overall low mesozooplankton biomass (median 4.5 mg C m(-3)). We also made a seasonal grazing study of five copepods with contrasting feeding modes (Calculus helgolandicus, Centropages typicus, Acartia clausi, Pseudocalanus elongatus and Oithona similis), counting the larger prey items from the natural seston. All species of copepod fed on all food types and differences between their diets were only subtle; the overriding driver of diet was the composition of the prey field. Even the smaller copepods fed on copepod nauplii at significant rates, supporting previous suggestions of the importance of intra-guild predation. All copepods, including O. similis, were capable of tackling extremely long ( > 500 mu m) diatom chains at clearance rates comparable to those on ciliates. Maximum observed prey:predator length ratios ranged from 0.12 (C. helgolandicus) up to 0.52 (O. similis). Unselective feeding behaviour and the ability to remove highly elongated cells have implications for how copepod feeding is represented in ecological and biogeochemical models.