首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 0 毫秒
1.
2006年秋季东海陆架浮游植物群集   总被引:5,自引:0,他引:5  
根据2006年11月19日--12月24日在东海陆架海域(24.0°--32.0°N,120.0°--127.0°E)进行的综合采样调查,对调查海域浮游植物的群集特征进行了研究.本次调查共发现浮游植物4门64属145种(包括未定名种),其中硅藻是该调查海区浮游植物的主要功能群,其次为甲藻.主要的优势种为菱形海线藻、圆海链藻、丹麦细柱藻、斯氏几内亚藻、尖刺伪菱形藻和铁氏束毛藻等.浮游植物细胞丰度为0.09~5.11 cells·ml-1,平均值为4.92 cells·ml-1,秋季东海陆架浮游植物细胞丰度的平面分布主要由浮游硅藻刻画,其高值出现在调查区的北、东部离岸海域,细胞丰度大于30 cells·ml-1.浮游植物及硅藻和甲藻的细胞丰度垂直变化趋势基本上都是随着水深增加,丰度逐渐减小.各个断面细胞丰度密集区主要集中在表层,个别站位的中层和底层也出现浮游植物密集区.调查区浮游植物的多样性指数平均值为2.80,其高值位于调查区东北和东南部,物种均匀度指数平均值为0.81,其高值位于调查区中部,生物多样性的分布与细胞丰度的分布一致.从Pearson相关性指数来看,亚硝酸盐、溶解态有机氮(DON)和温度显著影响调查区浮游植物的生长.  相似文献   

2.
2006年秋季东海陆架浮游植物群集   总被引:3,自引:0,他引:3  
根据2006年11月19日—12月24日在东海陆架海域(24.0°—32.0°N,120.0°—127.0 °E)进行的综合采样调查,对调查海域浮游植物的群集特征进行了研究.本次调查共发现浮游植物4门64属145种(包括未定名种),其中硅藻是该调查海区浮游植物的主要功能群,其次为甲藻.主要的优势种为菱形海线藻、圆海链藻、丹麦细柱藻、斯氏几内亚藻、尖刺伪菱形藻和铁氏束毛藻等.浮游植物细胞丰度为0.09~5.11 cells·ml-1,平均值为4.92 cells·ml-1,秋季东海陆架浮游植物细胞丰度的平面分布主要由浮游硅藻刻画,其高值出现在调查区的北、东部离岸海域,细胞丰度大于30 cells·ml-1.浮游植物及硅藻和甲藻的细胞丰度垂直变化趋势基本上都是随着水深增加,丰度逐渐减小.各个断面细胞丰度密集区主要集中在表层,个别站位的中层和底层也出现浮游植物密集区.调查区浮游植物的多样性指数平均值为2.80,其高值位于调查区东北和东南部,物种均匀度指数平均值为0.81,其高值位于调查区中部,生物多样性的分布与细胞丰度的分布一致.从Pearson相关性指数来看,亚硝酸盐、溶解态有机氮(DON)和温度显著影响调查区浮游植物的生长.  相似文献   

3.
东海大陆架鱼类群落的空间结构   总被引:14,自引:1,他引:14  
李圣法  程家骅  严利平 《生态学报》2007,27(11):4377-4386
根据1997~2000年东海大陆架水深30~200米海域4个航次的底拖网调查资料,运用多元分析(聚类分析和非度量多维标度(NMDS))、SIMPER以及BIO-ENV方法分析了东海鱼类群落的空间格局以及与非生物环境因子之间的关系。结果表明,东海大陆架海域鱼类群落在空间上可分为3个群落类型,分别为东海近海群落、东海大陆架外缘群落以及这两个群落之间的东海大陆架混合群落。东海大陆架鱼类群落的种类组成沿着水深梯度的变化明显,每种鱼类均有一定的水深范围。不同的流系具有不同的温盐特征,影响了鱼类的分布及其洄游,从而控制了不同鱼类群落类型的种类组成。东海大陆架鱼类群落类型中,大陆架外缘群落类型各调查季节在空间分布和种类组成上相对稳定,而东海近海群落类型和东海大陆架混合群落类型在夏季融合在一起,其它季节保持各自的空间结构。同时东海陆架区只在一种群落类型中出现的鱼类相对较少,多数鱼类同时出现在两个群落类型中或3个群落类型中,但是它们相对较集中的区域明显不同,在不同群落类型中的生物量和出现频率有很大的差异,这些鱼类在其不同的生长发育阶段由于对海洋环境的不同需求,它们根据繁殖或摄食需求而在东海陆架区范围内洄游以寻找最适的海洋环境,因此对3个群落类型定义是相对的,很难严格确定一个永久的鱼类群落地理区域,以形成相互隔离的鱼类群落,而且鱼类群落之间的边界随着季节不同发生变化。  相似文献   

4.
Living large benthic foraminifera (LBF) were analyzed from three transects of boxcores taken on a shelf off the coast of East Kalimantan, just north of the Mankalihat Peninsula. The transects were located at different distances to the mouth of the Berau river. In 45 boxcores, of which 28 contained living LBF, 20 species were recognised. They occurred in moderate to high density outside the pro-delta, i.e., outside the area with high clay and silt sedimentation. LBF characteristic of sandy substrates can be divided into two or possibly three assemblages, shallow (15–50 m), deep (50–85 m) and possibly very deep (> 85 m). The latter is poorly developed in the study area. Few LBF were recorded in one of the three transects, possibly because of either sediment instability or physical or chemical parameters of the sediment. Grain-size analysis of samples in the other transects indicates that LBF occurrence strongly modify the habitat. After colonisation, grain-size increases, creating more opportunities for other species and higher densities of LBF.  相似文献   

5.
Phylogenetic relationships among 33 Synechococcus strains isolated from the East China Sea (ECS) and the East Sea (ES) were studied based on 16S rRNA gene sequences and 16S–23S rRNA gene internal transcribed spacer (ITS) sequences. Pigment patterns of the culture strains were also examined. Based on 16S rRNA gene and ITS sequence phylogenies, the Synechococcus isolates were clustered into 10 clades, among which eight were previously identified and two were novel. Half of the culture strains belonged to clade V or VI. All strains that clustered into novel clades exhibited both phycoerythrobilin and phycourobilin. Interestingly, the pigment compositions of isolates belonging to clades V and VI differed from those reported for other oceanic regions. None of the isolates in clade V showed phycourobilin, whereas strains in clade VI exhibited both phycourobilin and phycoerythrobilin, which is in contrast to previous studies. The presence of novel lineages and the different pigment patterns in the ECS and the ES suggests the possibility that some Synechococcus lineages are distributed only in geographically restricted areas and have evolved in these regions. Therefore, further elucidation of the physiological, ecological, and genetic characteristics of the diverse Synechococcus strains is required to understand their spatial and geographical distribution.  相似文献   

6.
春季和秋季东、黄海陆架区大型网采浮游动物群落划分   总被引:7,自引:0,他引:7  
左涛  王荣  陈亚瞿  高尚武  王克 《生态学报》2005,25(7):1531-1640
根据2000年秋季和2001年春季对黄、东海大面调查中浮游生物大网(孔径500μm)采集的浮游动物样品,运用多元分析方法对陆架区内的浮游动物组成、分布、群落进行了研究。结果表明,春、秋两季陆架区浮游动物均可划分为5个群落:i黄海沿岸群落;ii黄海中部群落;iii黄、东海交汇水混合群落;iv东海近岸混合水群落;v东海外陆架高温高盐群落。各群落的种类组成及地理分布存在一定的季节差异。  相似文献   

7.
In vitro antimicrobial screening of nine marine sponges (Porifera) and two seaweeds, collected from south east coast of India, against selected clinical isolates of bacteria and fungi was conducted in this study. Methanolic extracts of all the marine organisms demonstrated activity against one or more of microbes tested. Sigmadocia carnosa was the most active exhibiting a broad spectrum antimicrobial activity against each of the microbe tested with the exception of Fusarium species. Contrary to this, the genus Echinogorgia did not show any detectable bactericidal activity but, Echninogorgia reticulata was weakly fungicidal against Rhodotorula species and E. compecta against Fusarium and Nocardia species. Considerable antibacterial activity was exhibited by Haliclona cribricutis and Chrotella australiensis against Klebsiella species and Vibrio cholerae, respectively. Petrocia testudinaria showed equally good activity against the bacterium V. chlorae and the fungus Cryptococcus neoformans. The sponges Callyspongia fibrosa, Ircinia species and the seaweed Stoecheospermum margilatum are totally inactive against fungi. The extracts showing good antimicrobial activity are undergoing further analysis to identify the active constituents.  相似文献   

8.
9.
于2011年春季(5月)和秋季(11月)在东海陆架区进行浮游纤毛虫丰度和生物量的调查.春季和秋季纤毛虫的平均丰度分别为(614±861)和(934±809) ind·L-1,平均生物量分别为(1.70±3.91)和(0.93±0.99) μg C·L-1.表层纤毛虫丰度和生物量的高值区春季主要分布在近岸及远岸海区,秋季主要分布在远岸海区.春季纤毛虫的丰度和生物量在水体上层较高;秋季纤毛虫主要分布在水体上层,有时在水体底层也会出现丰度和生物量的高值.春季无壳纤毛虫群落的粒级较大,秋季较小.砂壳纤毛虫占纤毛虫丰度的平均比例春季和秋季分别为(26.9±34.3)%和(44.9±25.2)%.两个季节共鉴定出砂壳纤毛虫27属52种,春季丰度较大的种为原始筒壳虫、橄榄领细壳虫及筒状拟铃虫,秋季丰度较大的种为原始筒壳虫、小领细壳虫及矮小拟铃虫.纤毛虫丰度与温度、叶绿素a(Chl a)浓度呈显著正相关.砂壳纤毛虫丰度与盐度呈显著负相关,群落结构变化与温度显著相关.  相似文献   

10.
A Japanese eel Anguilla japonica was collected off Kozushima Island, one of the volcanic Izu Islands in Japan. The external morphology corresponded to a silvering stage (Silvering Index: S1) with a melanized body coloration of the head, and the tip of the lower jaw to the anus. However, the value of the gonado-somatic index of the female eel was low, and the oocytes were not matured (peri-nucleolus stage). Otolith analyses indicated that the individual had exclusively inhabited the sea for five years without entering freshwater. This record is the first collection of silver-phased Japanese eel in the Kuroshio region, which could be on the spawning migration route of the species, although it was not determined if the eel was settling around the Izu Islands or migrating to the spawning ground.  相似文献   

11.
12.
东海具齿原甲藻的扫描电子显微结构   总被引:11,自引:2,他引:11  
在光学显微镜分析鉴定的基础上,通过高分辨率的扫描电子显微镜,对东海赤潮原甲藻标本和美国国家海洋藻种中心(CCMP)的具齿原甲藻(Prorocentrum dentatum)藻株(CCMPl517)的细胞表面结构进行观察和比较,认为两者为同一种类.在分析大量文献资料的基础上,可以认为发生在我国东海水域的赤潮原甲藻种类是具齿原甲藻(Prorocentrum dentatum),而非新种.  相似文献   

13.
A new genus and new species of Scorpaenidae,Ursinoscorpaenopsis kitai, is described based on single specimen, 239.7 mm standard length, collected by bull trawl at the bottom, 132 m deep, in the East China Sea. The specimen had a paranuchal spine, supplemental spine on the last suborbital spine and non-fleshy, polyfurcate pectoral fin rays (all unique to the genus), in addition to an orange-reddish body, toothless palatine, swimbladder, supraneural and five unfused hypurals.Ursinoscorpaenopsis seems to be one of the more primitive genera among the Scorpaenidae.  相似文献   

14.
15.
A cyanophage strain and its host Synechococcus were isolated from the East China Sea. The host Synechococcus sp. SJ01 was characterized by its 16S rRNA, ITS, and psbA gene sequences as well as by its morphological appearance and pigmentation. The cyanophage, strain S-SJ2, was able to cause a lytic infection of the coastal Synechococcus. TEM of negative-stained specimens showed that the phage isolate has an isometric head with a diameter of 68 nm and a long tail with a length of 280 nm. The cyanophage-Synechococcus system from the East China Sea shares many properties with other marine cyanophage-Synechococcus systems worldwide.  相似文献   

16.
As China’s second-largest large marine ecosystem, the East China Sea Shelf has suffered from overfishing, eutrophication, and physical disturbance over the last several decades. A trophic mass-balance model of this ecosystem was developed in order to characterize the structure and functioning of its food web, to identify its keystone species, and to quantify the ecological impacts of fishing that it sustained during the early 2000s. Using a multivariate statistical analysis, we identified 38 functional groups for the trophic model, including fish and invertebrate groups targeted and not targeted by fisheries. Pelagic sharks and rays were identified as the keystone species in the ecosystem. Strong benthic–pelagic coupling was indicated in this ecosystem. In particular, this study highlighted the interdependent relationships that exist among plankton, benthic invertebrates, and detritus. Recent fishing activities were characterized by high exploitation rates for various commercially targeted and non-targeted species, leading to the removal of much of the ecosystem’s fishable production. Overall, our findings give a preliminary explanation of the current problems of eutrophication and fishery depletion and other changes in the East China Sea Shelf, and highlight the need for developing ecosystem-based fisheries management.  相似文献   

17.
东海剧毒卡尔藻的形态特征及其系统进化分析   总被引:2,自引:0,他引:2  
利用光学显微镜、荧光显微镜、扫描电镜及分子生物学等方法, 对分布于我国东海海域的剧毒卡尔藻(Karlodinium veneficum)藻株(LAMB090611)的形态特征和显微结构进行了描述, 并探讨了其分子系统进化关系。该藻株细胞长11.1-18.7 μm, 平均值为(14.2±1.8) μm, 宽8.2-14.7 μm, 平均值为(10.8±1.5) μm。细胞形态结构特征为: 上下锥体积基本相同; 顶沟短而直; 腹孔明显; 纵沟延伸至上锥; 横沟错位距离约占细胞总长的28%-38%; 含有2或4个不规则形态的叶绿体; 细胞核位于中部或下锥。此藻种的暴发可引发有害赤潮(harmful algal bloom)。当前加强有害赤潮的预防和监测工作是减少危害的有效途径, 而对引发赤潮原因种的准确识别和鉴定则是基础和关键。  相似文献   

18.
Typhoons can cause strong disturbance, mixing, and upwelling in the upper layer of the oceans. Rich nutrients from the subsurface layer can be brought to the euphotic layer, which will induce the phytoplankton to breed and grow rapidly. In this paper, we investigate the impact of an intense and fast moving tropical storm, Typhoon Matsa, on phytoplankton chlorophyll-a (Chl-a) concentration off East China. By using satellite remote sensing data, we analyze the changes of Chl-a concentration, Sea Surface Temperature (SST) and wind speed in the pre- and post-typhoon periods. We also give a preliminary discussion on the different responses of the Chl-a concentration between nearshore and offshore waters. In nearshore/coastal regions where nutrients are generally rich, the Chl-a maximum occurs usually at the surface or at the layer close to the surface. And, in offshore tropical oligotrophic oceans, the subsurface maxima of Chl-a exist usually in the stratified water column. In an offshore area east of Taiwan, the Chl-a concentration rose gradually in about two weeks after the typhoon. However, in a coastal area north of Taiwan high Chl-a concentration decreased sharply before landfall, rebounded quickly to some degree after landfall, and restored gradually to the pre-typhoon level in about two weeks. The Chl-a concentration presented a negative correlation with the wind speed in the nearshore area during the typhoon, which is opposite to the response in the offshore waters. The phenomena may be attributable to onshore advection of low Chl-a water, coastal downwelling and intensified mixing, which together bring pre-typhoon surface Chl-a downward in the coastal area. In the offshore area, the typhoon may trigger increase of Chl-a concentration through uptake of nutrients by typhoon-induced upwelling and entrainment mixing.  相似文献   

19.
我国的海参   总被引:37,自引:0,他引:37  
概述了海参的形态、生物学特性、分类、经济意义、养殖和我国常见的食用海参。  相似文献   

20.
Drifting seaweeds plays a major role in areas where they are present. We describe a computer model, JeoSim that clarifies the roles of those seaweeds in relation to their transport using particle-tracking algorithm. The Euler rule with trapezoidal approximation, used to calculate drifting paths, is implemented in JeoSim in discrete events fashion in order to simulate the path and movement of seaweeds. Pre-processing of the ocean currents is done with the Princeton Ocean circulation Model (POM). Simulated current constitutes the data that provides force and directions for the calculations of drifting paths. Along with the implementation of the particle-tracking algorithm in discrete event fashion, the originality of the JeoSim software lies in its Object Oriented architecture which makes it especially suited to perform simulation of living, cross scale systems with complex behavior. Behavior of drifting seaweeds of the Sargasso family has been implemented in JeoSim, and experimented in East China Sea following a drifting seaweed collection campaign in May 2002. Despite a relatively low resolution ocean currents data, simulated results compare well with the observed distribution.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号