Cannibalism in omnivorous calanoid copepods
Cannibalism in omnivorous calanoid copepods
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DOI：
10.3354/meps047045
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发表时间：
1988
影响因子：
2.5
通讯作者：
R. Daan;S. Gonzalez;W. K. Breteler
中科院分区：
文献类型：
--
作者：
R. Daan;S. Gonzalez;W. K. Breteler
在研究北海南部桡足类种群动态的过程中，进行了桡足类成体捕食共生无节幼体的半原位实验。在一个时期内，无节幼体丰度的强烈下降，实验无节幼体死亡率的同类相食占常备库存的35%，每天。同时观察叶绿素a和浓度在原地和产卵的成年女性建议穷人的食物条件。在没有其他食物的情况下，似乎有增加捕食行为的趋势，表明同类相食作为无节幼体死亡率的一个因素可能很重要。显微镜下观察和一系列实验室培养Temora longicornis发现成年女性捕食阶段N-I通过N-V。捕获率下降，上升的发展猎物阶段。猎物特定的捕食率不断增加的猎物密度，但显着抑制M替代藻类食物的存在。基于实验确定的捕食率，估计仅由于同类相食而导致的无节幼体原位死亡率解释了估计的总无节幼体死亡率的5%至超过100%。有人建议，同类相食可能作为一个主要因素，无节幼体死亡率，并可能有助于显着的快速下降，无节幼体密度在藻类食物短缺的时期。
During a study on population dynamics of copepods in the southern North Sea some semiin-situ experiments were performed on predation by adult copepods on CO-occurring nauplii. In a period with a strong decline in naupliar abundance, experimental naupliar mortality by cannibalism amounted to 35% of the standing stock per day. Simultaneous observations on chlorophyll a and concentrations in situ and on egg production by adult females suggested poor food conditions for adults. There appeared to be a tendency for increased predatory behaviour in the absence of other food, indicating the possible importance of cannibalism as a factor in naupliar mortality. Microscopic observations and a series of experiments on laboratory cultured Temora longicornis revealed adult female predation on stages N I through N V. Rates of capture declined with ascending developmental prey stage. Prey-specific predation rates increased continuously with prey density, but were significantly depressed m the presence of alternative algal food. Estimates of naupliar mortality in situ due only to cannibalism, based on experimentally determined predation rates, explained 5 to over 100 % of the estimated total naupliar mortality. It is suggested that cannibalism may act as a major factor in naupliar mortality and may contribute significantly to a rapid fall in naupliar densities in periods of algal food shortage.