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本工作据1987年3月我国第三次南极考察采集的样品,测定了南极磷虾及其所在海域海水中Pb,Cu,Cd,Zn,Fe和Mn等痕量金属含量,计算出南极磷虾对各重金属的富集系数。 相似文献
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I~IOWFluorine is one of fewer biogenic ndcroelernent, which has two thresholds. In certain extentcontent, fluorine plays an ~ant ace in constructing and growing normally for organisms. Incontrast, too high or too low content is not gabs for living being growing (Chen and Yu, 1988).In general, nuorine in seawater is known as one of conversation elements, and the average contentof nuorine of all world ocean seawater is 1. 3o rug/dln3(Chen et al., 1987).Under high fluorine seawat(lr environmen… 相似文献
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南大洋磷虾富氟机制Ⅰ.氟的化学赋存形态研究 总被引：1，自引：0，他引：1
通过对南极大磷虾（Ｅｕｐｈａｕｓｉａ ｓｕｐｅｒｂａ）进行活体生长培养,对其不同部位及生长过程中不同阶段样品进行了氟的形态赋存分析,研究表明磷虾中９０％的氟集中在甲壳中,在其生长脱壳周期中,甲壳和肌肉中的氟含量呈相对应的周期性变化,在脱壳后最初新甲壳和肌肉中氟含量较低,通过生物主动吸收,海水中氟迅速被有效吸收和转化,而磷虾所吸收的氟最终又以存在于旧甲壳中随磷虾脱壳而丢失．在磷虾的生长周期中甲壳和肌肉中的不同化学形态氟赋存变化充分证明了这一点．最后提出了磷虾富氟机制的一个过程模式． 相似文献
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南大洋磷虾富氟机制Ⅰ.氟的化学赋存形态研究 总被引：5，自引：0，他引：5
通过对南极大磷虾(Euphausia superba)进行活体生长培养,对其不同部位及生长过程中不同阶段样品进行了氟的形态赋存分析,研究表明磷虾中90%的氟集中在甲壳中,在其生长脱壳周期中,甲壳和肌肉中的氟含量呈相对应的周期性变化,在脱壳后最初新甲壳和肌肉中氟含量较低,通过生物主动吸收,海水中氟迅速被有效吸收和转化,而磷虾所吸收的氟最终又以存在于旧甲壳中随磷虾脱壳而丢失。在磷虾的生长周期中甲壳和肌肉中的不同化学形态氟赋存变化充分证明了这一点。最后提出了磷虾富氟机制的一个过程模式。 相似文献
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分布混合分析的深入研究及其在南极磷虾种群结构中的应用 总被引：1，自引：0，他引：1
介绍分布混合分析的理论，并运用分布混合分析估计南极磷虾种群体长分布概率密度函数的参数，首次给出体长取样间有效性和方差ａ＾２下限的数学分析。概率密度函数式为Ｑ（ｘ）＝ｋ∑ｊ＝１ｐｊｑ（ｘ；ｕｊ，ｑｊ），式中ｘ是随机变量体长的取值；Ｋ是年龄组数；ｐｊ是第Ａｊ年龄组的强度；ｑ（ｘ；ｕｊ，ｑｊ）是均值为ｕｊ；方差为ａ＾２ｊ的正态分布。Ｐｊ，ｕｊ，δｊ，ｊ＝１，２，…，Ｋ是待估计的参数。求解这些参数的最大似 相似文献
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The spatial and temporal characteristics of trophic structure of fish communities in the southern Huanghai Sea were examined based on the data sampled from bottom trawl surveys conducted during the autumn of 2000 and the spring of 2001. Hierarchical agglomerative cluster method and bootstrap randomization were used to identify significant trophic groups for each fish assemblage in the southern Huanghai Sea. A total of six major trophic groups were identified within this system, which classified predators based upon location in the water column or prey size （ i. e. , benthic to pelagic predators or fish to small invertebrate prey predators）. The similarity level used to identify significant trophic groups in each assemblage ranged from 24% to 34%. Although planktivores were the dominant trophic group in each assemblage （60% - 79% ）, there were spatial and temporal variations in the trophic structure, which reflected the differences in the abundance and availability of dominant preys. Simplified food webs were constructed to evaluate the most important trophic relationships between the dominant prey taxa and the fishes in each assemblage within this system. Although there were some differences in the key prey species among different food webs, pelagic prey items （mainly euphausiids and copepods） represent the most important energetic link between primary producers and higher trophic level predators. The trophic level for most fishes was between 3 and d, and the weighted mean trophic level for each assemblage ranged from 3.3 to 3.4. Compared with previous study in the mid-1980s, there was an obvious downward trend in the trophic level for most fish species, which resulted mainly from the fluctuation in key prey species in the Huanghai Sea. The decrease in the importance of Japanese anchovy seems to be offset by other abundant prey species such as Euphausia pacifica and copepods （ mainly Calanus sinicus ） . 相似文献
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Multivariate principal components analysis and cluster analysis were performed on data representing presence or absence of 498 species of juvenile and adult fish species in twenty-four coastal marine systems (bays, coastal lagoons, estuaries and coastal zones) distributed from southeast to southern Brazil. Five groups of coastal systems were identified based on fish assemblage similarity: estuaries and bays of the southeast area; an estuary of the southern area; coastal lagoons; rocky coastal zones; and the continental platform. Species assemblages for each zone were identified and used as surrogate habitat indicators to compare and contrast the groups. Stepwise multiple regression of environmental and physical variables as predictors of the number of species indicated that only ‘ area ’ was included in the model as the most important variable explaining the variation of the number of species in these data sets. The total number of fish species increased as surface area increased. 相似文献
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点带石斑鱼亲鱼培育、产卵和孵化的试验研究 总被引：21，自引：2，他引：21
采用经埋植外源激光法诱导所得的点带石斑鱼功能性雄鱼和人工养殖的雌鱼进行亲鱼培育、产卵和孵化的试验研究，在1999-2000年的两年中，繁殖仔鱼7103万尾，结果表明，雌鱼的绝对生死力为535.01万粒卵，相对生殖力为810.21粒/g体重，水泥池中培育的点带石斑鱼能自然产卵与水温相关，水温高于24℃时，产卵呈一定的周期性，即连续产卵5-7天，停产数天后再开始下一个产卵周期；水温低于24℃时，产卵受到抑制，水温对胚胎发育有明显的影响，水温25.5-28.5℃胚胎发育时间为21h53min，仔鱼活力好，盐度为30-33时，胚胎发育正常盐度降低造成孵化率下降。 相似文献