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71.
遗传标记技术在海洋桡足类生物多样性和系统发生研究中的应用 总被引:3,自引:0,他引:3
研究回顾遗传标记技术的发展及其在海洋桡足类分类学、群体遗传学、系统发育和分子进化研究等方面的应用情况。 相似文献
72.
Benthic, viable resting eggs of calanoid copepods were found for the first time in the Seine estuary (France) during July 2008. Vertical distribution of the resting eggs in the sediment was determined up to 10 cm depth. Hatching success of the eggs extracted from different 1-cm thick sediment layers was experimentally tested immediately after extraction and after a long refractory phase (i.e. 11 months) of storage at low temperature (4–5 °C). The hatching success of resting eggs obtained immediately after sediment incubation was lower (0.72%) than the value observed after 11 months (4.50%) with an overall hatching success of 2.37%. The marine, calanoid copepod Temora longicornis was the primary species to hatch from the eggs; however, the estuarine calanoid copepod Eurytemora affinis also hatched from resting eggs. The mean abundance of eggs found in sediment (1.42 × 106 eggs m−2) was comparable to that reported for other marine and estuarine calanoid copepods. The Seine estuary sediment had a high variability of egg abundance (between 0.14 and 8.10 × 107 eggs m−3) suggesting that the hydrodynamics of this macrotidal estuary are likely responsible for this variability. Significant sediment resuspension occurs in the Seine estuary during flood periods and spring tides leading to resting eggs to contribute along the year to the nauplii recruitment of calanoid copepods. On average, around 400,000 nauplii m−3 month−1 of the main calanoid copepods can emerge from the surface layer sediment in the Seine estuary, suggesting that resting eggs could play an important role in the population dynamics of key calanoid copepods in the Seine estuary. 相似文献
73.
洋山港浮游桡足类群落的周年变化特征 总被引:1,自引:0,他引:1
研究了洋山港海域桡足类的周年生态特征。结果显示,洋山港桡足类的优势种为四刺窄腹剑水蚤(Limnoithona tetraspina)、太平洋纺锤水蚤(Acartia pacifica)、真刺唇角水蚤(Labidocera euchaeta)、针刺拟哲水蚤(Paracalanus aculeatus)、双毛纺锤水蚤(Acartia bifilosa)、小毛猛水蚤(Microsetellanorvegica)、瘦拟哲水蚤(Paracalanus gracilis)和小拟哲水蚤(Paracalanus parvus);桡足类丰度季节变化显著(F=2.11,P<0.05),春(28.44个/L±19.16个/L)>夏(18.60个/L±14.81个/L)>冬(10.98个/L±3.65个/L)>秋(10.57个/L±4.45个/L);生物量则为夏(12359.1 mg/L±18438.1 mg/L)>秋(7796.6 mg/L±1348.6 mg/L)>冬(2944.8 mg/L±1680.9 mg/L)>春(1401.0 mg/L±1057.3 mg/L)。桡足类丰度的周年变化呈现双峰型特征,生物量变化呈现单峰型特征。多变量分析显示,优势种的数量变化对洋山港桡足类群落丰度和生物量的季节变化起主要作用。小洋山码头受人类干扰严重,桡足类丰度和多样性与大洋山码头已出现差异,春、冬季小洋山码头的多样性指数(H′)高于大洋山码头,除秋季外,小洋山码头的均匀度指数(J)都高于大洋山码头。 相似文献
74.
B. R. Stanton 《新西兰海洋与淡水研究杂志》2013,47(1):141-163
The results of a hydrological survey of the Karamea Bight, on the west coast of the South Island, are presented and discussed. The hydrology of the region was dominated by the Westland Current, the river outflow and wind‐induced upwelling. The existence of a southwards flowing undercurrent associated with the upwelling is postulated at 150 m depth over the continental slope, and the name of Westland Undercurrent is proposed for this feature. 相似文献
75.
塔西南其木干早二叠世玄武岩的喷发时代及地球化学特征 总被引:4,自引:4,他引:0
塔西南其木干剖面棋盘组玄武岩是塔里木盆地早二叠世大火成岩省西南部的重要组成部分,根据其下伏和上覆砂岩地层的碎屑锆石U-Pb年龄分析可以限定其喷发于~284Ma,相应于柯坪地区开派兹雷克组玄武岩的形成时代。其木干玄武岩的主量元素和Cr、Ni等相容元素含量变化较大,表明其曾经历广泛的橄榄石、辉石和长石结晶分异作用;所研究样品相对富集Th、U和LREE,具有弱-中等程度的Eu负异常 (Eu/Eu*=0.82~0.99),在微量元素蛛网图上显示Nb-Ta负异常;较低的εNd(t) (-4.8~-3.9) 和εHf(t) (-2.4~-1.6) 值、较高的 (87Sr/86Sr)i (0.7078~0.7086)和存在Hf-Nd同位素解耦等特征表明,其木干玄武岩的源区为受远洋沉积物组分交代富集的岩石圈地幔,该富集过程主要与Rodinia超大陆聚合过程有关。总体上,其木干玄武岩的地球化学特征类似于柯坪地区的开派兹雷克组玄武岩,但具有更为富集的Sr-Nd-Hf同位素,暗示了塔里木板块周缘比板内地区可能经受了更强烈的远洋沉积物组分的交代富集。 相似文献
76.
Gyo-Hyuk Byun Hyo-Bang Moon Jung-Hwa Choi Jeomshik Hwang Chang-Keun Kang 《Marine pollution bulletin》2013
Concentrations of polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), and polybrominated diphenyl ethers (PBDEs) were measured in 32 species inhabiting the Yellow Sea to assess their bioaccumulation potentials. The concentrations in these samples were lower than those reported for other countries or locations. Relatively high levels of BDE 209 in biota suggest an ongoing source of deca-BDE technical mixing within the Yellow Sea. The accumulation profiles of PCBs were uniform between species, but the concentrations of OCPs and PBDEs varied widely. Pelagic and benthic food-chain components were separated by their δ13C values. Significant positive correlations between δ15N and PCB 153, PCB 138, p,p′-DDE, oxy-chlordane, and trans-nonachlordane were found only for pelagic consumers, indicating that the pelagic food chain is an important bioaccumulation pathway for selected PCB and OCP compounds. The other compounds did not show any biomagnification through benthic and pelagic food chains, suggesting the lower bioaccumulation potentials of these contaminants. 相似文献
77.
We analyzed long-term (56-year) variations in springtime biomass of the zooplankton of the California Current System from two primary regions sampled by CalCOFI: Southern California (SC) and Central California (CC) waters. All organisms were enumerated from the plankton samples and converted to organic carbon biomass using length-carbon relationships, then aggregated into 19 major taxa. Planktonic copepods dominate the carbon biomass in both SC (59%) and CC (46%), followed by euphausiids (18% and 25% of mean biomass in SC and CC, respectively). Pelagic tunicates, especially salps and doliolids, constituted a higher fraction of the biomass in CC (13%) than in SC (5%). There was no long-term trend detectable in total zooplankton carbon biomass, in marked contrast to a decline in zooplankton displacement volume in both regions. The difference between these biomass metrics is accounted for by a long-term decline in pelagic tunicates (particularly salps), which have a relatively high ratio of biovolume:carbon. The decline in pelagic tunicates was accompanied by a long-term increase in water column density stratification. No other taxa showed a decline over the duration of the study, apart from salps and pyrosomes in SC and doliolids in CC. Some zooplankton taxa showed compensatory increases over the same time period (ostracods, large decapods, and calycophoran siphonophores in both SC and CC; appendicularians and polychaetes in SC). Two tests for ecosystem shifts, a sequential algorithm and the cumulative sum of anomalies (CuSum) approach, failed to detect changes in 1976-1977 in total carbon biomass, displacement volume, or most individual major taxa, suggesting that aggregated biomass is an insensitive indicator of climate forcing. In contrast, both techniques revealed a cluster of step-like changes associated with the La Niña of 1999. The major El Niño’s in the past half century have consistently depressed total zooplankton biomass and biomass of many major taxa in both SC and CC, although such effects are transitory. Much, but not all, of the interannual variability in zooplankton is shared between the Southern and Central California sectors of the California Current System. 相似文献
78.
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80.
海洋桡足类滞育卵在海水养殖业中的应用及其前景 总被引:1,自引:0,他引:1
海洋桡足类作为小型甲壳动物 ,是鱼虾类良好的天然饵料 ,其繁殖和培养将在现代海水养殖业中发挥重要的作用。本文就桡足类滞育卵的产生、控制条件和在养殖业上的潜在价值等进行了综述 相似文献