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1.
紫霞湖浮游甲壳动物昼夜垂直迁移及其影响因子分析   总被引:1,自引:0,他引:1  
2010年9月19 ~21日,对江苏南京紫霞湖(水深8.5 m)浮游甲壳动物昼夜垂直迁移行为进行了调查,分析了影响昼夜垂直迁移的因素.结果表明,奥氏秀体溞(Diaphanosoma orghidani)、象鼻溞(Bosminasp.)、颈沟基合溞(Bosminopsis deitersi)、台湾温剑水蚤(Thermocyclops taihokuensis)和中华原镖水蚤(Eodiapotomus sinensis)成体均表现出昼夜迁移现象,中华原镖水蚤幼体和无节幼体无明显昼夜迁移.紫霞湖的温度、溶解氧和叶绿素a浓度的垂直变化不是导致浮游甲壳动物昼夜垂直迁移的主导因子,光照强度和鱼类捕食可能是影响浮游甲壳动物昼夜垂直迁移的主要因素.  相似文献   

2.
2010年9月19~21日,对江苏南京紫霞湖(水深8.5m)浮游甲壳动物昼夜垂直迁移行为进行了调查,分析了影响昼夜垂直迁移的因素。结果表明,奥氏秀体溞(Diaphanosoma orghidani)、象鼻溞(Bosmina sp.)、颈沟基合溞(Bosminopsis deitersi)、台湾温剑水蚤(Thermocyclops taihokuensis)和中华原镖水蚤(Eodiapotomus sinensis)成体均表现出昼夜迁移现象,中华原镖水蚤幼体和无节幼体无明显昼夜迁移。紫霞湖的温度、溶解氧和叶绿素a浓度的垂直变化不是导致浮游甲壳动物昼夜垂直迁移的主导因子,光照强度和鱼类捕食可能是影响浮游甲壳动物昼夜垂直迁移的主要因素。  相似文献   

3.
水产养殖     
020662盐度,冷藏和强化对镖水蚤Glnd-iofere,,5 17,IPari娜的影响=Effeets of salini-ty,eold storage and enriChment on theealanoid coPepod Gladioferens imPariPes〔刊,英〕/P ayne MF,Rippingele RJ//Aquae.一2001,201(3/4)一251一262 镖水蚤的集约化培养技术已经建立,尽管通过这种培养,可获得可靠和长期的镖水蚤无节幼体供应,但要使用来投喂仔鱼的无节幼体的数量达到最大,营养价值达到最佳状态,对这种技术还需作进一步的改进。已表明,盐度对挠足类的培养以及延长藻类强化时间对无节幼体的营养成分均有影响。采用冷藏的方法可…  相似文献   

4.
(二)浮游动物 1.浮游动物的种类组成及分布丹江库区的浮动物共检出52种(其中原生动物14种,以砂壳虫为优势种;轮虫计23种,以壶状臂尾轮虫,针簇多肢轮虫占优势;枝角类11种,以秀体藻,小栉蚤为优势;桡足类检索至目主要有镖水蚤,剑水蚤猛水蚤和无节幼体.桡足类在浮游动物中占有较大比重,见表6。  相似文献   

5.
太湖新银鱼幼体在千岛湖中分布特点的初步研究   总被引:1,自引:0,他引:1  
太湖新银鱼(NeosalanxtaihuensisChen)幼体在千岛湖的分布与它所摄取的食料生物群体分布有着明显的依从关系;光照、水流、透明度等影响浮游生物昼夜之间垂直分布,幼银鱼追逐这些食物,故也存在着昼夜迁移现象  相似文献   

6.
水产养殖     
011264培养镖水蚤Glndiofer卿:im扭r-i加:的饵料评价=Evaluation of diets for cu-loure of the calanoid copePed Gladidj计ensimPariPes[刊,英]/P ayre MF,.Rippin-gale RJ// Aquac.一2000,’187(1龙)一85一96 对许多采用标准工艺很难饲养的鱼类,用挠足类无节幼体作为饵料可提高仔鱼的成活率。镖水蚤G.im扭ri娜是一种温水性河口种类,、具有开发的前景。试验采用各种24饵料,旨在探讨大量培养的最佳工艺。投喂5种饵料:球等鞭金藻,牟氏角毛藻,盐藻,微绿球藻和面包酵母。在20℃和25℃条件观测缥水蚤的成活率、成熟期、成熟率、无节幼体…  相似文献   

7.
2013年8月1日19∶00至2日18∶00,通过间隔1 h的定量采样,研究南昌市典型城市湖泊月亮湖中浮游动物(轮虫、枝角类和桡足类)的昼夜垂直分布规律。结果表明,月亮湖共发现浮游动物20种,其中轮虫16种,枝角类1种,桡足类3种;剪形臂尾轮虫(Brachionus forficula)、桡足类无节幼体(Copepoda Nauplii)和迈氏三肢轮虫(Filinia maior)为优势物种,分别占总捕获数量的48.27%、15.75%和11.11%。浮游动物主要类群和优势物种的Morisita指数均大于1,说明月亮湖中的浮游动物群落呈聚集分布。密度垂直分布和平均滞留深度分析结果显示,浮游动物垂直分布昼夜差异明显,夜间(19∶00-05∶00),浮游动物先聚集于月亮湖中层,01∶00后逐渐迁移到表层;白天(06∶00-18∶00),浮游动物逐渐从表层向中层和底层迁移;主要类群中轮虫、枝角类和桡足类的迁移均表现为夜间上升、白天下降、傍晚再上升,轮虫和桡足类的迁移幅度小于枝角类。优势种剪形臂尾轮虫和无节幼体的昼夜垂直迁移表现为夜升昼降,至傍晚再上升;迈氏三肢轮虫昼夜垂直分布差异显著(P0.05),但昼夜垂直迁移活动不明显。相关分析表明,水温、p H值和溶解氧对月亮湖浮游动物的垂直分布和迁移活动有显著影响。  相似文献   

8.
通过对固城湖浮游生物、底栖动物和高等水生植物等渔业生物资源的现状调查和历史资料对比,探讨了固城湖当前渔业生物资源时空分布差异和群落结构变化趋势。研究结果表明,固城湖7月绿藻、蓝藻为优势种,4月时绿藻、硅藻为优势种,群落生物量急剧上升,生物群落趋于小型化。浮游动物群落枝角类以长额象鼻溞、短尾秀体溞、诺氏僧帽溞、蚤状溞为优势种,桡足类除了无节幼体与桡足幼体,以跨立小剑水蚤、中华窄腹剑水蚤为优势种,种类组成显示固城湖处于中富营养状态。底栖动物近年来腹足类种类数量减少,寡毛类和摇蚊幼虫种类和生物量上升。高等水生植物锐减厉害,仅发现少许的菹草和苦草分布,生物量较少。研究结果为加强固城湖生物资源的适度利用和环境资源的合理保护提供数据基础。  相似文献   

9.
白洋淀浮游甲壳动物的生物多样性研究   总被引:2,自引:0,他引:2       下载免费PDF全文
基于2006年4月至2006年12月对白洋淀浮游甲壳动物进行采样调查,分析了白洋淀浮游甲壳动物的群落结构及多样性。本次调查共记录到浮游甲壳动物34种,隶属于9科19属,其中枝角类(Cladocera)19种,桡足类(Copepoda)16种。物种多样性季节性明显:枝角类优势种在春、夏和秋冬季依次为微型裸腹溞(Moina micrura)、长额象鼻溞(Bosmina longirostris)、长肢秀体溞(Diaphanosoma leuch);而桡足类优势种在冬春季为英勇剑水蚤(Cyclopidae strenuus),在夏秋季为锯缘真剑水蚤(Eucyclopinae macruroides)和台湾温剑水蚤(Thermocyclops tsihokurnsis)。物种多样性春秋季较高,夏季和冬季较低。浮游甲壳类个体密度以春季最高,冬季最低。根据生物多样性指数综合判定白洋淀的水质为中营养化水平。  相似文献   

10.
枝角类和桡足类在河蟹育苗中的应用试验   总被引:3,自引:0,他引:3  
枝角类和桡足类广泛分布于淡水、海水及内陆咸水水域,俗称水蚤、鱼虫、虾仔,它隶属于节肢动物门、甲壳纲,尤其是海水种类体内含有大量的不饱和脂肪酸,是鱼、虾、蟹幼体的重要饵料。枝角类主要种类为裸腹蚤;桡足类主要种类为海产猛水蚤和哲水蚤及淡水中的镖水蚤。这些种类中绝大多数均可作为河蟹育苗不同阶段各期幼体的适口饵料。1999~2000年在河蟹人工育苗中,我们用该饵料部分或全部替代代用饵料及卤虫卵,取得了较高的产量及较好的经济效益。1 材料与方法1 1 材料本试验设备采用天然海水人工育苗场进行河蟹育苗的原有设备,枝角类和桡…  相似文献   

11.
To investigate their diel vertical migration (DVM), 599 sablefish (Anoplopoma fimbria) were implanted with electronic archival tags in the Gulf of Alaska, Aleutian Islands, and the eastern Bering Sea. Of these tags, 98 were recovered with usable depth data (7,852,773 recordings representing 81,233 days) that we used to identify DVM and to classify DVM into one of two types: normal DVM (rise from the bottom during nighttime) and reverse DVM (rise from the bottom during daytime). The results of our study highlight three important attributes of DVM for sablefish. First, all tagged sablefish carried out DVM, although the occurrence was intermittent (26% of the days with usable data) and most commonly for short durations (10 days or less). Second, bottom depth for normal DVM was about 78 m shallower than for reverse DVM. Third, normal DVM occurred most often in fall and least often in spring, whereas this high/low pattern was shifted about 3 months later for reverse DVM; reverse DVM occurred most often in winter and least often in summer. Normal DVM likely occurred to increase foraging opportunity (e.g., nightly shift to match depth of prey). Reverse DVM more commonly occurred during winter and may represent an increase in foraging by sablefish during the daytime to compensate for decreased pelagic resources. The default foraging strategy for sablefish may be benthic because of the uncertainty of vertically migrating to a location where the occurrence of prey is not guaranteed; sablefish may invoke DVM when the non‐DVM foraging benefit is reduced.  相似文献   

12.
Abstract –  Seasonal variation in light intensity has strong impacts on invertebrate and vertebrate habitat selection creating trade-offs between foraging gain and risk of death. Diel vertical migration (DVM) has received a particularly interest, but multitrophic level studies in lakes under polar light regime have not been conducted. Here, we examined habitat selection of pelagic zooplankton, planktivores and piscivores in subarctic Lake Muddusjärvi with polymorphic whitefish ( Coregonus lavaretus (L.)). Seasonal change in light was hypothesized to be the most important abiotic factor inducing DVM, whereas predation was considered as an ultimate biotic factor. During period of mid-night sun in June, no DVM was observed at any trophic level, whereas during normal day and night light in September planktivores and zooplankton migrated. DVM was top-down controlled, where piscivorous brown trout ( Salmo trutta L.) used pelagic habitat continuously inducing DVM of its main prey, pelagic whitefish morph, which cascaded to reverse DVM of zooplankton. Top-down control of lower trophic level DVMs by piscivores might be more general pattern in lakes than previously considered.  相似文献   

13.
Diel vertical migration (DVM) is a common zooplankton behavior in which organisms reside in surface or near‐surface waters at night and at deeper depths during the day. In many upwelling regions, DVM reduces the transport of organisms away from the region. It is unclear, however, what role DVM plays in recruitment (the arrival of larvae or juveniles to locations where they will become reproducing adults) to upwelling regions. In this study, we estimate the influence of DVM on zooplankton transport, the level of recruitment of locally produced propagules (self‐recruitment), and sources of recruits in the upwelling region near Monterey Bay, California, by simulating the trajectories of fixed‐depth and vertically migrating organisms with a drifter‐tracking algorithm driven by climatological velocity fields from a three‐dimensional hydrodynamic model. Our simulations suggest that DVM into subsurface poleward and onshore currents during the day does not fully compensate for equatorward and offshore transport in the surface Ekman layer at night and does not retain zooplankton in the Monterey Bay region. Our simulations also suggest that DVM decreases the ability of zooplankton to return to the region after being transported away and shifts source regions for recruits closer to the bay. While DVM does not appear to substantially increase the potential for self‐recruitment to the region, this study indicates that other mechanisms, such as transport during non‐upwelling periods, continuous transport below the surface, increases in mean transport depth over time, or seasonal changes in hydrography, may still enable relatively high levels of self‐recruitment to this highly advective region.  相似文献   

14.
Abstract – We sampled three limnetic fish species: juvenile sockeye salmon (Oncorhynchus nerka), three‐spine stickleback (Gasterosteus aculeatus) and longfin smelt (Spirinchus thaleichthys) in Lake Washington to quantify species‐specific patterns of diel vertical migration (DVM). Catch‐per‐unit‐effort data analysed from 15 years of midwater trawling documented seasonal and diel differences in vertical distributions for each species. These results were consistent with the hypothesis that the patterns of DVM in Lake Washington were affected by life history, size and morphology. Sockeye salmon showed clear DVM in spring but essentially no DVM in fall, remaining in deep water, whereas three‐spine sticklebacks were prevalent at the surface at night in both seasons. In fall, distribution patterns may be explained by differences in thermal performance (e.g., sticklebacks favouring warm water), but the patterns were also consistent with inter‐specific differences in predation risk. Younger sockeye salmon and longfin smelt were present in greater proportions higher in the water column during dusk and night periods than older conspecifics. Compared with sockeye salmon, the greater use by three‐spine sticklebacks of surface waters throughout the diel cycle during weak thermal stratification in spring was consistent with the hypothesis that sticklebacks’ armour reduces predation risk, but use of this warmer, metabolically beneficial stratum may also have promoted growth. This study illustrates variation in the vertical distribution of three sympatric planktivores and offers broader implications for the DVM phenomenon and applied lake ecology.  相似文献   

15.
Many species living in deeper lentic ecosystems exhibit daily movements that cycle through the water column, generally referred to as diel vertical migration (DVM). In this study, we applied bioenergetics modelling to evaluate growth as a hypothesis to explain DVM by bull trout (Salvelinus confluentus) in a thermally stratified reservoir (Ross Lake, WA, USA) during the peak of thermal stratification in July and August. Bioenergetics model parameters were derived from observed vertical distributions of temperature, prey and bull trout. Field sampling confirmed that bull trout prey almost exclusively on recently introduced redside shiner (Richardsonius balteatus). Model predictions revealed that deeper (>25 m) DVMs commonly exhibited by bull trout during peak thermal stratification cannot be explained by maximising growth. Survival, another common explanation for DVM, may have influenced bull trout depth use, but observations suggest there may be additional drivers of DVM. We propose these deeper summertime excursions may be partly explained by an alternative hypothesis: the importance of colder water for gametogenesis. In Ross Lake, reliance of bull trout on warm water prey (redside shiner) for consumption and growth poses a potential trade‐off with the need for colder water for gametogenesis.  相似文献   

16.
Generalized linear models were used to assess the influence of diel vertical migration (DVM) on Continuous Plankton Recorder data for adult (stages V and VI) Calanus finmarchicus . To simplify interpretation, the data were first divided into individual months and modelled using a Generalized Linear Model incorporating factors for long-term trend and daylight. The fitted models reveal that, at certain times of the year and particularly during the spring and autumn, the chances of catching a stage V or VI C. finmarchicus at 7 m depth are greater in darkness than during daylight. The magnitude of DVM was shown to be generally statistically independent of long-term trend, which is a conclusion that fails to support other published results produced from the same data.  相似文献   

17.
朱国平  杨洋  王芮  童剑锋 《水产学报》2018,42(10):1541-1549
近年来,南极磷虾渔业过于集中于布兰斯菲尔德海峡,这也使得该海区磷虾资源状况及其生态学特征日益受到关注。南极磷虾群具有较为明显的昼夜垂直移动特征,开展此方面的研究可为探索其渔场形成机制提供基础数据,并为磷虾渔业反馈式管理提供参考。基于磷虾渔船上Simrad EK80记录的相关声学数据,使用Echoview软件判别声学数据中的磷虾群体,对2016年秋季布兰斯菲尔德海峡南极磷虾群昼夜垂直移动特征进行分析,并进一步分析影响磷虾群昼夜垂直移动的因素。结果显示,3月和4月磷虾群深度基本维持在250 m以浅,虾群最大深度出现在日升时分的频次最高(22.9%),而最浅深度出现在夜间时分的频次最高(36.0%),同时在日升时分,虾群厚度达到最大值;白天磷虾群多集中在较深水层,夜间会上浮到较浅水层。随着月份的推移,磷虾群平均深度总体呈现加深的趋势。光强和海底深度是影响磷虾群深度变化的2个主要因素。  相似文献   

18.
2013年冬季南乔治亚岛南极磷虾群昼夜垂直移动研究   总被引:10,自引:6,他引:4  
关于冬季南极磷虾群昼夜垂直移动方面的研究可为探索其渔场形成机制提供基础数据,并为其越冬策略研究提供参考。基于2013年冬季南乔治亚岛南极磷虾渔业调查期间收集的相关数据,对冬季南乔治亚岛南极磷虾群昼夜垂直移动进行了研究。结果发现,磷虾群平均深度维持在表层以下100~300 m,磷虾群最深出现在日升时分,而最浅则出现在夜间时分;7—9月,随时间的推移,磷虾群所处水层呈加深趋势。夜间、白天和黄昏时段磷虾群平均深度呈现较为明显的月份差异。白天磷虾群多集中在较深水层,夜间会上浮到较浅水层。  相似文献   

19.
A biophysical model of the Irish Sea was produced to predict net horizontal movement of key taxa including small copepods (Acartia, Pseudocalanus), large copepod species (Calanus finmarchicus and C. helgolandicus), the euphausiid Meganyctiphanes norvegica, and the larval stages of commercially important fish and Nephrops. The model coupled biological information on the vertical distribution and diel vertical migration (DVM) of these taxa with temporally resolved flow fields generated by a baroclinic hydrodynamic model. The DVM of Calanus spp. and Meganyctiphanes was parameterized empirically from data provided by a biophysical campaign carried out in the nearby Clyde Sea. Small copepods and larvae remained within the layers above the thermocline. Model organisms, programmed with particular behavioural patterns, were spaced at regular intervals (1/20° longitude × 1/30° latitude) in the model grid, which extended from 53 to 54.5°N and 4.5 to 6.4°W. The model was run over the months of April, May and June. Model simulations showed that the movement of model organisms followed one of four characteristic patterns: containment along the coast, advection to the north or south, stagnation in the centre of the gyre or circulation around the periphery of the gyre. The latter pattern was apparent even in April, when gyral circulation was not expected because of a lack of stratification in the water column. Thirty‐day model runs in April, May and June showed that the number of organisms retained within the model grid varied between 23 and 49%. Those seeded close to the Irish coast had the highest probability of being retained within the model grid at the end of 90 days. DVM increased the probability of retention through improving the chances of organisms becoming entrained within the gyre circulation. This was especially true for Calanus spp., with those performing midnight sinking being the most likely to be retained out of any model organism. Meganyctiphanes showed comparatively lower levels of retention in deep regions, which suggests that they may have to swim against currents during certain phases of their DVM to avoid displacement. Overall, model results supported a number of hypotheses on the origin and fate of various taxa in the Irish Sea, as well as revealing some less expected distribution patterns.  相似文献   

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