Effects of food concentration and diet on chromophoric dissolved organic matter accumulation and fluorescent composition during grazing experiments with the copepod Calanus finmarchicus     

Urban-Rich  Juanita; McCarty  James T; Shailer  Mark 《ICES Journal of Marine Science》2004,61(4):542-551

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Standing Crops of Planktonic Ciliates and Copepod Nauplii in the Subarctic North Pacific and the Bering Sea in Summer     

Hiroshi Ito  Akira Taniguchi 《Journal of Oceanography》2001,57(3):333-339

Abundances and biomasses of planktonic ciliates and copepod nauplii, major components of the microzooplankton community, were investigated in the subarctic North Pacific and the Bering Sea in summer of 1997. Their regional variation was illustrated by demarcating the entire area into five regions. Ciliates always predominated both in abundance (>94%) and biomass (>78%) over nauplii. Regional means of ciliates in the water column were higher in the Alaskan Gyre (120 × 10⁶ cells/m²) and the Western Subarctic Gyre (110 × 10⁶ cells/m²) in terms of abundance, and rich in the Bering Sea Gyre (360 mgC/m²) and the Western Subarctic Gyre (340 mgC/m²) in terms of biomass. By contrast, standing crops of ciliates were poor in the Oyashio Region (67 × 10⁶ cells/m²; 170 mgC/m²) and the Transition Region (64 × 10⁶ cells/m²; 160 mgC/m²). The values of biomass reported here are generally in agreement with the values reported previously from the Bering Sea Gyre and the Alaskan Gyre but are considerably higher than the previous value found in the Western Subarctic Gyre. No significant correlations could be found between chlorophyll a crop and standing crops of ciliates and copepod nauplii over the entire subarctic North Pacific and the Bering Sea during this summer.  相似文献   

台湾北部近岸海域春末浮游动物的组成及分布特征     

陈禾张  黄将修  连光山 《台湾海峡》2004,23(1):62-68

本研究于2003年5月5日至6日对台湾北部近岸海域，具有地区特征的5个测站进行浮游动物数量、组成等调查研究．结果共发现22大类浮游动物，桡足类为此次调查的主要优势大类，约占总浮游动物个体数量的42．57％，其次为桡足幼体(copepodids)。占27．38％，两者在各测站的出现率皆高达100％．根据浮游动物丰度比较、群聚分析与水文状况，可将东北3个测站与西北2个测站分为两个不同的群落．其中，西北部测站可能因沿岸溪流大量有机物的注入，有利浮游动物增生，因此丰度较高，但5个测站的浮游动物多样性皆不高，与台湾其它沿岸海域研究结果相似．  相似文献   

东海精致真刺水蚤(Euchaeta concinna)种群生态特征   总被引：8，自引：2，他引：8  

徐兆礼 《海洋与湖沼》2006,37(2):97-104

根据1997—2000年东海23°30′—33°00′N、118°30′—128°00′E海域4个季节海洋调查资料,采用聚集强度等生态学方法和回归方差贡献等统计分析方法,对东海浮游桡足类精致真刺水蚤自然种群特征进行了研究,并与1979—1980年资料进行比较。结果表明,精致真刺水蚤在东海的优势性主要表现在秋季;其丰度和优势度有显著的季节变化,依次为秋季>冬季>夏季>春季;除夏季东海北部近海丛生指标I为1·34外,冬、春和夏3季I均为负值,秋季I值最高,有明显的聚集现象。与20年前结果相比,东海精致真刺水蚤优势度和占浮游桡足类总丰度的比例有所上升,这种现象可能与全球气候变暖相关。底层水环境的变化和暖流势力的强弱是影响东海精致真刺水蚤数量分布的主要因子。  相似文献   

Copepod growth in detail: pattern similarity to decapod larvae     

Miller  Charles B. 《ICES Journal of Marine Science》2008,65(3):332-338

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Hydrodynamics of Copepods: A Review     

Houshuo Jiang  Thomas R. Osborn 《Surveys in Geophysics》2004,25(3-4):339-370

This paper reviews the hydrodynamics of copepods, guided by results obtained from recent theoretical and numerical studies of this topic to highlight the key concepts. First, we briefly summarize observational studies of the water flows (e.g., the feeding currents) created by copepods at their body scale. It is noticed that the water flows at individual copepod scale not only determine the net currents going around and through a copepods hair-bearing appendages but also set up a laminar flow field around the copepod. This laminar flow field interacts constantly with environmental background flows. Theoretically, we explain the creation of the laminar flow field in terms of the fact that a free-swimming copepod is a self-propelled body. This explanation is able to relate the various flow fields created by copepods to their complex swimming behaviors, and relevant results obtained from numerical simulations are summarized. Finally, we review the role of hydrodynamics in facilitating chemoreception and mechanoreception in copepods. As a conclusion, both past and current research suggests that the fluid mechanical phenomena occurring at copepod body scale play an important role in copepod feeding, sensing, swarming, mating, and predator avoidance.  相似文献   

Seasonal variation in the community and size structure of nano- and microzooplankton in Gyeonggi Bay,Yellow Sea     

Eun Jin Yang  Joong Ki Choi  Jung-Ho Hyun 《Estuarine, Coastal and Shelf Science》2008

To investigate the seasonal variation and community structure of nano- and microzooplankton in Gyeonggi Bay of the Yellow Sea, the abundance and carbon biomass of nano- and microzooplankton were evaluated at 10-day intervals from January 1997 to December 1999. Four major groups of nano- and microzooplankton communities were classified: heterotrophic ciliates, heterotrophic dinoflagellates (HDF), heterotrophic nanoflagellates (HNF), and copepod nauplii. The total carbon biomass of nano- and microzooplankton ranged from 10.2 to 168.8 μg C L⁻¹ and was highest during or after phytoplankton blooms. Nano- and microzooplankton communities were composed of heterotrophic ciliates (7.4–81.4%; average 41.7% of total biomass), HDF (0.1–70.3%; average 26.1% of total biomass), copepod nauplii (1.6–70.6%; average 20.7% of total biomass), and HNF (0.8–59.5%; average 11.5% of total biomass). The relative contribution of individual components in the nano- and microzooplankton communities appeared to differ by seasons. Ciliates accounted for the most major component of nano- and microzooplankton communities, except during summer and phytoplankton blooming seasons, whereas HDF were more dominant during the phytoplankton blooming seasons. The abundance and biomass of nano- and microzooplankton generally followed the seasonal dynamics of phytoplankton. The size and community distribution of nano- and microzooplankton was positively correlated with size-fractionated phytoplankton. The carbon requirement of microzooplankton ranged from 60 to 83% of daily primary production, and was relatively high when phytoplankton biomass was high. Therefore, our result suggests that the seasonal variation in the community and size composition of nano- and microzooplankton appears to be primarily governed by phytoplankton size and concentration as a food source, and their abundance may greatly affect trophic dynamics by controlling the seasonal abundance of phytoplankton.  相似文献   

Primers to block the amplification of symbiotic apostome ciliate 18S rRNA gene in a PCR-based copepod diet study   总被引：1，自引：0，他引：1  

衣晓燕  张寰  刘光兴 《中国海洋湖沼学报》2014,32(3):515-521

Pelagic copepods play an important role in the marine food web. However, a full understanding of the ecological status of this zooplankton group depends on the careful study of their natural diets. In previous PCR-based copepod diet studies, we found many apostome ciliates that live symbiotically under the exoskeleton of the copepods, and their sequences were often over-represented in the 18S rRNA gene （18S rDNA） libraries. As a first step to address this issue, we designed three apostome ciliate 18S rDNA blocking primers, and tested their blocking efficiency against apostome ciliate 18S rDNA under various PCR conditions. Using a semi-quantitative PCR method, we optimized the conditions to efficiently amplify the 18S rDNA of the prey while simultaneously excluding the symbiotic apostome ciliates. This technique will facilitate PCR-based diet studies of copepods and other zooplankton in their natural environments.  相似文献   

Effects of residual chlorine on the mortality, grazing and respiration of Labidocera euchaeta (Copepoda)     

MA Zengling  LIN Hongping  GU Xiaolian  XU Zhaoli 《海洋学报(英文版)》2011,30(2):96-102

In this study,the authors investigated the effects of residual chlorine on mortality,grazing and respiration of Labidocera euchaeta in laboratory.The grazing rate was evaluated by subtraction method of food concentration and respiration rate was measured using oxygen electrode.It was found that the lethal effect of residual chlorine on L.euchaeta increased with enhanced concentration and prolonged duration.The medium lethal concentration (LC 50 ) of chlorine for L.euchaeta in 24 h was about 0.58 mg/L and the safe concentration was about 0.21 mg/L.However,the grazing and respiration of L.euchaeta decreased by 32.6% and 18.9% when exposed to 0.2 mg/L residual chlorine for 4 h.It indicated that the physiological activities of zooplankton could be suppressed by the residual chlorine less than the safety concentration.Therefore,both survival and physiological activities of the organisms living in the thermal (nuclear) power plant discharging waters should be considered when carrying out the ecological risks assessment.  相似文献   

利用脂肪酸标记法对南极罗斯海桡足类优势物种的食性研究     

王延清  张晔  牟文秀  庞志鹏  陈晓丽 《海洋科学》2021,45(12):31-38

脂肪酸标记法是浮游动物食性研究的一种重要方法.将提取的脂质区分为中性脂和极性脂,可以进一步查明不同脂质在浮游动物食性研究中的作用.本研究通过分析不同脂质的脂肪酸构成,对2013年1月中国第29次南极考察期间在罗斯海采集的5种优势种桡足类的食性进行了研究.结果显示:5种桡足类的极性脂脂肪酸具有相似的组成,无法给出桡足类食性差异信息,食性信息主要体现于中性脂脂肪酸组成的差异.通过分析中性脂脂肪酸的组成信息,将5种桡足类的食性分为三类:Cala-noides acutus和Calanus propinquus主要摄食浮游植物,Metridia gerlachei及小型桡足类Oncaea curvata为杂食性种,Paraeuchaeta antarctica为肉食性种.本文的结果说明,在应用脂肪酸作为浮游动物食性标记的研究中,应尽量区分不同脂质种类的脂肪酸信息,从而得到更为精确的浮游动物食性信息.  相似文献