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1.
本文以春季大鹏湾夜光藻种群等间隔采样序列作为随机过程变量,运用随机过程理论,构造了夜光藻种群超阈值风险的成丛随机点过程复合模型,对夜光藻赤潮风险率的随机过程进行分析,得到夜光藻赤潮的风险估算,并进行拟优合度检验.认为研究结果对预测夜光藻赤潮发生具有一定的指导意义.  相似文献   

2.
周静韵  张磊  安民  段舜山 《生态科学》2012,31(4):396-400
以我国典型赤潮藻赤潮异弯藻(Heterosigma akashiwo)为研究对象,设置了6个浓度梯度(0 mg·L-1、0.001mg·L-1、0.01 mg·L-1、0.1 mg·L-1、1 mg·L-1和10 mg·L-1)的草甘膦异丙胺盐处理,研究了草甘膦异丙胺盐暴露对赤潮异弯藻的生长、叶绿素a含量和可溶性蛋白含量等指标的影响.结果表明,草甘膦异丙胺盐对赤潮异弯藻具有明显的毒性效应,10 mg·L-1浓度处理下,赤潮异弯藻细胞大量死亡,藻细胞密度以及叶绿素a、可溶性蛋白的含量显著降低(p<0.05);当草甘膦异丙胺盐浓度在0.001~1 mg·L-1范围内,在培养的第3 d草甘膦异丙胺盐能够显著促进赤潮异弯藻的细胞密度增加,叶绿素a含量也明显高于对照组(p<0.05),表现出毒物刺激效应;在暴露实验的中后期(第7 d、第9 d和第11 d),赤潮异弯藻的各生长指标均与对照无显著差异,可能是随着培养时间的延长,农药的降解、生物体对农药的适应、进入细胞的农药减少等原因,藻细胞生理状态逐渐恢复到正常水平.  相似文献   

3.
粤东柘林湾中肋骨条藻(Skeletonema costatum)种群生态学   总被引:2,自引:0,他引:2  
于2000年5月~2004年12月对粤东大规模养殖区柘林湾的赤潮藻中肋骨条藻(Skeletonema costatum)种群的时空分布进行了长达5a的调查。结果表明,中肋骨条藻种群密度的周年变动模式基本为双峰型,平面分布没有显著的空间差异。调查期间,中肋骨条藻种群密度的站位实测值为0~1.4×10^7cells/dm^3,总均值为3.3×10^5cells/dm^3,占浮游植物总细胞数的67.1%,为调查海区第1优势种。在总共1045份样品中,有中肋骨条藻出现的样品数为1020份。其中,种群密度大于10^6cells/dm^3的样品有65份,大于10^7cells/dm。则有4份。以大于10^6cells/dm^3为中肋骨条藻的赤潮密度标准,在调查期间至少于2000年、2003年发生4次赤潮。运用灰关联理论对中肋骨条藻种群密度与13个环境因子的关系进行排序分析发现,水温、pH值和浮游动物是影响柘林湾中肋骨条藻种群时空分布的关键因子。水温还与中肋骨条藻种群密度的对数值具极显著意义的线性关系,而达到赤潮密度的样品均落在24.5~32.0℃区间,即每年的5~9月份高温季节。由于柘林湾浮游动物的年高峰期也出现在高温季节,说明浮游动物摄食压力的存在可能是柘林湾中肋骨条藻赤潮发生的重要抑制因子。2004年调查海区中肋骨条藻种群密度和在浮游植物群落中的优势度骤然降低,可能与水体营养盐结构和Fe含量的变化有关。因此,长期调查与监测对于研究海湾生态学和赤潮发生机制是极为重要的。  相似文献   

4.
南海北部沿海夜光藻赤潮的生态模式研究   总被引:3,自引:2,他引:3  
本文根据1980~1991年南海北部沿海发生的夜光藻赤潮资料,介绍了夜光藻的生物学特征.生态学特征,从夜光藻发生赤潮的起始、发展、维持和消亡四个阶段分析和探讨其发生机制,提出了夜光藻赤潮的生态模式。研究表明:夜光藻赤潮各阶段的消长过程受到物理、化学和生物因素的制约.这些因素在夜光藻赤潮发生的不同阶段所起的作用是不一样的,其发生机制仍然存在着生物地理学的差异等。  相似文献   

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为探究不同食物及食物密度对盐蚕豆虫(Fabrea salina)种群动力学的影响。本文采用商业酵母和杜氏藻(Dunaliella salina)两种不同类型的饲料喂食盐蚕豆虫,探究其种群动力学特征。结果表明,杜氏藻组的盐蚕豆虫具有较高的生长率[(0.78 ± 0.019)/d]、较低的世代时间[(0.89 ± 0.021)d],内禀生长率为1.49/d,米氏常数值为1 121.32;商业酵母组生长率较低[(0.36 ± 0.001)/d],世代时间较长[(1.93 ± 0.007)d],内禀生长率为0.51/d,米氏常数值为2.68。One-way ANOVA检验结果表明,食物及食物密度对盐蚕豆虫的种群生长均有极显著影响(P < 0.01)。以密度为10 × 109 cells/L的杜氏藻投喂,可在短时间内实现盐蚕豆虫的高密度培养和利用,而酵母适用于实验室中盐蚕豆虫的保种工作。  相似文献   

6.
大鹏湾生态因子灰关联分析   总被引:8,自引:0,他引:8  
研究大鹏湾夜光藻、反曲原甲藻、浮游动物种群增殖与浮游动物和海水理化因子之间的关系,采用的方法是根据它们的种群增殖态势与浮游动物和理化因子的比较,依据空间理论的数学基础,按照规范性、偶对称性、整体性和接近性这四条原则,确定参考数列(母序列:夜光藻和反曲原甲藻、浮游动物)和若干比较数列(子序列:浮游动物和海水理化因子)之间的关联度.给出各因子对母序列影响的排列次序.其结果是,对大鹏湾生态环境起主要影响的因子有浮游动物、锰、铁和溶解氧  相似文献   

7.
大鹏湾沙头角海域富营养化与赤潮发生的初步研究   总被引:1,自引:1,他引:0  
报道南海大鹏湾沙头角海域由于工业废水和生活污水的大量流入,使该海域氮、磷和化学需氧量逐年升高,使其富营养化程度值达1.497~11.773,因而近年来冬春季节赤潮发生频繁。主要的赤潮生物有夜光藻NoclilucaSctutllams、裸甲藻Gymnodiniumsp.,中肋骨条藻Skele-tonemaCostatum、海洋原甲藻Prorocentrummicans、海链藻Thalssiosirasp.和角毛藻Chaelocerassp.等。由于该海湾是半封闭性海域,因而赤潮发生的强度较大,其数量为2.7×10 ̄6~8.4×10 ̄4个/m ̄3,生物多样性指数为0.146~0.250.其毒性较大,危害沿岸渔业生产。  相似文献   

8.
于2000年5月~2004年12月对粤东大规模养殖区柘林湾的赤潮藻中肋骨条藻(Skeletonema costatum)种群的时空分布进行了长达5a的调查。结果表明,中肋骨条藻种群密度的周年变动模式基本为双峰型,平面分布没有显著的空间差异。调查期间,中肋骨条藻种群密度的站位实测值为0~1.4×107 cells/dm3,总均值为3.3×10cells/dm3,占浮游植物总细胞数的67.1%,为调查海区第1优势种。在总共1045份样品中,有中肋骨条藻出现的样品数为1020份。其中,种群密度大于106 cells/dm3的样品有65份,大于107 cells/dm3则有4份。以大于106 cells/dm3为中肋骨条藻的赤潮密度标准,在调查期间至少于2000年、2003年发生4次赤潮。运用灰关联理论对中肋骨条藻种群密度与13个环境因子的关系进行排序分析发现,水温、pH值和浮游动物是影响柘林湾中肋骨条藻种群时空分布的关键因子。水温还与中肋骨条藻种群密度的对数值具极显著意义的线性关系,而达到赤潮密度的样品均落在24.5~32.0℃区间,即每年的5~9月份高温季节。由于柘林湾浮游动物的年高峰期也出现在高温季节,说明浮游动物摄食压力的存在可能是柘林湾中肋骨条藻赤潮发生的重要抑制因子。2004年调查海区中肋骨条藻种群密度和在浮游植物群落中的优势度骤然降低,可能与水体营养盐结构和Fe含量的变化有关。因此,长期调查与监测对于研究海湾生态学和赤潮发生机制是极为重要的。  相似文献   

9.
杨家新  黄祥飞 《生态学报》2000,20(5):728-732
分别利用泥鳅-藻-轮虫和罗非鱼-藻-轮虫共生隔离培养的方法,研究萼花臂尾轮虫(Brachionus calyciflorus)的种群密度和主要环境因子的变化。研究结果表明:加入泥鳅的培养缸中,有11d轮虫数量超过100ind/ml,其中有5d超过200ind/ml,最高密度达250ind/ml;在罗非鱼的培养缸中,在整个实验过程中,种群密度超过100ind/ml以上的时间有6d(第5-10天);单  相似文献   

10.
山东海域赤潮灾害特征及预警报管理   总被引:2,自引:0,他引:2  
掌握赤潮灾害时空分布规律是科学设计赤潮监控方案、提高防灾管理效率的基础和依据。本文统计分析了1990—2010年间山东海域的76次赤潮灾害事件数据。结果表明:赤潮灾害频率显著地分为4个波段,且峰值呈递增趋势;灾害面积呈现周期性倒U型曲线变化;每年的5—10月是赤潮灾害的多发期,其中,8月的灾害次数和灾害面积均占全年总数的30%以上;灾害空间分布集中在莱州湾海域、青岛近海、庙岛群岛的北隍城海域,烟台四十里湾的赤潮灾害最频繁;夜光藻(Noctiluca scintillans)和球型棕囊藻(Phaeocystis globosa)引发的赤潮灾害面积最高,夜光藻和红色裸甲藻(Gymnodinium sanguineum)致灾次数最多。本文从赤潮监测与信息采集、赤潮预报方法以及赤潮灾害预警报管理机制3个方面分析总结了山东海域赤潮灾害预警报业务化管理现状,结合山东海域赤潮灾害特征和预警报管理实践,提出了以控制污染和修复生态环境为根本的赤潮防控建议。  相似文献   

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The distribution of the endangered species Boros schneideri was studied by checking the presence of larvae and adults under the bark of dead Pinus sylvestris trees in 13 pine forests in Lithuania. B. schneideri was found in 10 biggest pine forests, the area of which exceeded 20,000 ha. However, it was not detected in smaller isolated forests. In Kazlų Rūda, Šimonys, Pabradė and Rūdiškės forests this species was recorded for the first time. The part of localities in which B. schneideri was found and the percentage of trees with B. schneideri were significantly higher in the main parts of the biggest forests than in satellite or smaller forests. Both these parameters were significantly lower in forests located in the close vicinity of urban territories than in forests further from them. Consequently, the forest size and the distance of the forest from urban territories were found to be of critical importance for the survival and density of the B. schneideri population. These distribution regularities are important for the establishment of protected areas for this species conservation.  相似文献   

14.
This study aimed to analyze the reproductive cycle of the crab Hepatus pudibundus (Herbst, 1785). The crabs were collected in Ubatuba, SP (23 degrees 26'S and 45 degrees 02'W) monthly from the July, 1992 to June, 1993. Samplings were performed with an "otter trawl". In the laboratory the crabs were numbered, sexed and measured for their maximum carapace width. The gonad developmental stage and the moult stage were also macroscopically registered. In all sampled months ovigerous females and crabs in both sexes with developed gonad were observed. Moult activity in all size classes was verified. Such fact indicates that this species can suffer moult process after their maturity. In despite of temperature being pointed a one of the most important ecological factor in the reproductive biology of aquatic animals, it was verified any relation between water temperature and ovigerous ratio. The oscillations of the environmental factors in the Ubatuba region sea probably were not enough to alter the continuity of the physiological processes related to H. pudibundus reproduction.  相似文献   

15.
ABO, rhesus and Kell blood group data on 1327 donors in Kabul are analysed by ethnic affinity and compared with existing data on Afghanistan peoples. Blood group frequencies are very similar in Pushtu and Tadjik, despite their different historical, linguistic, and cultural backgrounds. Inclusion of the small sample of Hazara in the analysis shows overall heterogeneity in rhesus D, E, and e frequencies, suggesting the existence of a broader pattern of genetic variation among the peoples of Afghanistan.  相似文献   

16.

The net-wing beetle Lopheros lineatus (Gorham, 1883), previously known in the western Palaearctic only from Poland, and in the eastern Palaearctic, from the southern Russian Far East and from Japan, is discovered in Mordovia, Central Russia.

  相似文献   

17.
Armendáriz  Laura C. 《Hydrobiologia》2000,438(1-3):217-226
Population dynamics of Stylaria lacustris were analyzed over 2 years in a pond located at Los Talas, Argentina. In both years, the peak in abundance, due to intense asexual reproduction, fell at the end of winter, and was followed by mature individuals. The species was not collected during summer. Temperature was the main factor regulating the population through both sexual and asexual reproduction. In the second year, density was lower and correlated with a lower water level and a reduced vegetation development. Individuals were randomly distributed in periods of high abundance and contagious when density was low. Generation time was 15 days.  相似文献   

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Spermiogenesis of the syncarid Anaspides tasmaniae (subclass Eumalacostraca) was investigated by transmission electron microscopy. The spermatozoan of Anaspides is an ovoid cell with an acrosome covering the anterior pole and a lobulated nucleus and mitochondria occupying the rest of the cell. A long subacrosomal filament bypasses the nucleus and forms a spiral that supports a thin extension of the posterior cytoplasm, giving the spermatozoan a bell-shaped appearance. No flagellum is present at any stage. The immobile spermatozoans are embedded in a hard capsule, secreted by the cells of the wall of the vas deferens.  相似文献   

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