| 摘要: |
| 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。 |
| 关键词: 浮游动物, 浮游桡足类,精致真刺水蚤,东海 |
| DOI： |
| 分类号: |
| 基金项目:我国近海海洋综合调查与评价专项,908-02-01-03号;国家重点基础研究发展规划(973)项目,2001CB409707号 |
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| ECOLOGICAL CHARACTERS OF EUCHAETA CONCINNA (COPEPOD) IN THE EAST CHINA SEA |
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XU Zhao-Li
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Key and Open Ecological Laboratory of Marine and Estuary, Ministry of Agriculture of China, East China Sea Fisheries Research Institute, Chinese Academy of Fisheries Sciences, Shanghai
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| Abstract: |
| Based on the data from seasonal oceanographic survey in the East China Sea (23°30′–33°N, 118°30′–128°E) during 1997-2000, the authors discussed the ecological characteristics of Euchaeta concinna population in the East China Sea with analytical methods of aggregation indices and regression contribution. Comparison of the observations made between 1979–1980 and this investigation was carried out The abundance of E. concinna showed a clear seasonal change in following order: autumn (14.11 ind/m3)>winter (0.64ind/m3)>summer (0.39 ind/m3)>spring (0.06 ind/m3). E. concinna predominated mainly in pelagic copepods in autumn. In spring, the copepods took only 0.78% of the total pelagic copepods, 1.87% in summer and 5.79% in winter, but 25.12% in autumn. All the clumping indices (I) of the species were negative through the year and peaked in autumn, except for being positive 1.34 along northern offshore in summer. The autumn peak indicated the phenomenon of aggregation. Ambient factors influencing the abundance of E. concinna were selected on the basis of step-wise regression. The results showed that the abundance in autumn and summer were remarkably correlated with bottom salinity, whereas they showed less significant correlation with other ambient factors. The overall abundance in four seasons was clearly related to bottom temperature. Compared with the results obtained in 1979–1980, this study revealed that dominance and abundance of E. concinna in the area have increased, indicating that the ecological importance of E. concinna in pelagic copepods have been developing in the East China Sea. This phenomenon may be related to global warming. Environmental changes in bottom water, especially in warm currents, were the main factors affecting the abundance of E. concinna. However, because they can tolerate in low temperature, for example, 14–16°C in spring and 12–16°C in winter in northern nearshore of East China Sea. The population densities were more than 1.00ind/m3. E. concinna was not a good indicator of warm currents, reflected by the second high occurrence frequency (89.23%) and average abundance (0.64 ind/m3) in winter. The high-abundance area of E. concinna in northern area of East China Sea would provide some clue to local fisheries. |
| Key words: Zooplankton, Pelagic copepod, Euchaeta concinna, The East China Sea |
