共查询到20条相似文献，搜索用时 109 毫秒
1.
为了检验已记录的3种裸腹溞(发头裸腹溞(Moina irrasa)、短型裸腹溞(Moina brachiata)、微型裸腹溞(Moina micrura))的系统分类,用试剂盒法分别提取3种裸腹溞的基因组DNA.利用特异性引物,通过PCR扩增了3种裸腹溞的16S r DNA部分序列,并与来自Gen Bank中每个种类相似度较高的裸腹溞属序列进行分析.结果表明,3种裸腹溞的平均种间相似度为88.7%,碱基中A+T含量均明显高于G+C含量.本研究的发头裸腹溞的16S r DNA序列与Gen Bank所下载的多刺裸腹溞(Moina macrocopa)的16S r DNA序列相似度为99%,遗传距离(K2P双参考模型)为0.5%,属种内范围;两个地区的短型裸腹溞测得的16S r DNA序列与Gen Bank下载的欧洲短型裸腹溞的16S r DNA序列序列相似度相对较低(88%~90%),遗传距离较大(13.2%~13.5%左右),已达到属内种间分化水平.基于16S r DNA构建的NJ树和贝叶斯树也支持以上结论.结果表明,本研究的发头裸腹溞可能为多刺裸腹溞,本研究用的短型裸腹溞与Gen Bank下载的欧洲短型裸腹溞已经达到种间分化的标准.由于缺乏物种形态资料和其他分子标记的对比,3种裸腹溞的分类地位还需进行更深入的探讨. 相似文献
2.
微囊藻是形成蓝藻水华最普遍的一种,不同枝角类受微囊藻的影响不同.实验从太湖梅梁湾分离天然的微囊藻,研究了其对长刺溞、隆线溞、短尾秀体溞和角突网纹溞四种枝角类存活和生殖的影响.在微囊藻食物浓度为1×106 cells/ml,测得四种枝角类的半致死时间(LT50)分别为长刺溞3.03 d、隆线溞3.79 d、短尾秀体溞8.48 d和角突网纹溞9.25 d,体长较小的短尾秀体溞和角突网纹溞的半致死时间相对较长;实验过程中没有观察到长刺溞和隆线溞有新生幼体,而短尾膊秀体溞和角突网纹溞在少数几天里产出了少量新生幼体.以不同浓度微囊藻(0.5×106-8×106 cells/ml)喂养枝角类,测得四种枝角类的24h半致死浓度(LC50)分别为:4.10×106、4.78×106、6.21×106和7.77×106 cells/ml.参照以栅藻喂养的枝角类生长情况,可知太湖微囊藻对四种枝角类的存活和生殖有很强的负面作用,其中体长较大的长刺溞和隆线溞受的影响相对较大. 相似文献
3.
本文研究了典型的鄱阳湖阻隔湖泊——军山湖沉积物(0~36 cm)中溞属枝角类卵鞍密度的长期变化.1~#和2~#采样点36 cm沉积层对应的年代分别为1839和1857年.1958年前,军山湖沉积物的沉积速率呈现较高的水平,而1959年建坝后的沉积速率明显减小.1958年前,军山湖沉积物中总氮和总磷含量相对稳定,但建坝后总氮含量呈现明显增加的趋势.在军山湖沉积物中,鉴定出中华拟同形溞(Daphnia similoides sinensis)、盔形溞(D.galeata)和蚤状溞(D.pulex)的卵鞍.1~#和2~#沉积柱中3种溞属种类总卵鞍和含休眠卵卵鞍的累积速率和密度呈现较一致的变化.1958年前,3种溞属种类总卵鞍和含休眠卵卵鞍的累积速率和密度均处于较低水平(1~#沉积柱:0~1.51×10~3ind./(m~2·a)和0~0.63 ind./(g·dw);2~#沉积柱:0~0.70×10~3ind./(m~2·a)和0~0.22 ind./(g·dw));1959年建坝后,10~1 cm的沉积层中3种溞属种类总卵鞍和含休眠卵卵鞍的累积速率和密度呈现逐步增加的趋势,尤其是在3~1 cm(2009-2015年)的沉积层.Pearson相关性显示,军山湖1~#沉积柱中的总氮含量与3种溞属种类的总卵鞍和含休眠卵卵鞍的累积速率之间均存在极显著相关性.2~#沉积柱中的总氮和总磷含量均与3种溞属种类总卵鞍的累积速率之间存在显著相关性.2~#沉积柱的总氮和总磷含量还与中华拟同形溞的含休眠卵卵鞍的累积速率之间均存在显著相关性.结果表明,沉积物中营养盐含量和溞属种类卵鞍(或休眠卵)的长期变化能够反映湖泊富营养化和溞属种群的历史演变过程. 相似文献
4.
5.
枝角类作为淡水湖泊生态系统中的初级消费者之一,对生存环境的改变极为敏感.本文分析了太湖西、中和东部等湖区的钻孔沉积物、表层沉积物以及春夏秋季活体枝角类的组成与丰度.结果表明:活体枝角类组成以象鼻溞(Bosmina spp.)为优势种,秋季枝角类属种数量最多.太湖不同生态型湖区表层沉积物枝角类组成均以象鼻溞为优势种,其中西部与中心湖区的枝角类组成与丰度较为相似,种类单一,枝角类绝对丰度高;东部湖区枝角类属种较为丰富,绝对丰度低,优势种由浮游种象鼻溞以及沿岸种圆形盘肠溞(Chydorus sphaericus sl)和西方笔纹溞(Graptoleberis testudinaria)等种属构成.百年以来,太湖枝角类组成与丰度随着营养水平增加而改变,富营养指示种(Bosmina longirostris)丰度的增加与贫营养指示种(Bosmina longispina)丰度的下降,响应了湖区生态环境的演变过程.1970s末期,太湖西部与中心湖区在进入富营养化阶段,枝角类组成单一,象鼻溞占有绝对优势,与东部湖区相比,沿岸种、底栖种稀少.东部湖区在1960s以后,枝角类属种数量增加,但丰度下降,响应了1960s以来该区域营养水平提高、沉水植被生物量增加以及沼泽化加剧的环境过程. 相似文献
6.
沉积物再悬浮对浮游动物群落结构影响的模拟实验 总被引：5，自引：1，他引：4
沉积物再悬浮是浅水湖泊的重要特征之一.通过模拟实验,比较不同再悬浮程度下浮游动物群落结构的变化,以探讨沉积物再悬浮对浮游动物的影响.结果显示,不同处理下总悬浮物与叶绿素a浓度差异显著.再悬浮组中枝角类简弧象鼻溞(Bosmina coregoni)、角突网纹溞(Ceriodaphnia cornuta)和轮虫占优势,而对照组中大型枝角类溞属(Daphniasp.)占优势,再悬浮使浮游动物群落组成趋于小型化.不同再悬浮条件下隆线溞(Daphnia carinata)、简弧象鼻溞(Bosmina coregoni)和轮虫的丰度差异显著,角突网纹溞(Ceriodaphnia cornuta)和桡足类丰度差异不显著.总悬浮物浓度与轮虫和简弧象鼻溞丰度显著正相关,与隆线溞丰度显著负相关,与其它浮游动物种群丰度无显著相关性.本研究显示,沉积物再悬浮是决定浮游动物群落结构变化的重要过程之一. 相似文献
7.
淮北采煤塌陷区小型湖泊浮游甲壳动物群落结构的季节变化 总被引：2，自引：2，他引：0
2005年3月至2007年2月对淮北采煤塌陷区小型湖泊--南湖浮游甲壳动物进行了连续两年的调查.共记录浮游甲壳动物15种,其中枝角类9属9种、桡足类5属6种.透明溞(Daphnia hyalinaLeydig)和汤匙华哲水蚤(Sinocalanus dorrii Brehm)为冬、春季优势种;象鼻溞(Bosmina sp.)、短尾秀体溞(Diaphanosoma brachyurumLiéven)、广布中剑水蚤(Me-socyclops leuckarti Claus)和球状许水蚤(Schmackeria forbesi Poppe et Richard)为夏、秋季优势种.浮游甲壳动物密度和生物量分别为0.4-60.6ind./L和0.01-1.25mg/L,夏、秋季较高,冬、春季较低.枝角类的密度和生物量在2005年和2006年10月均达到最大值,分别为44ind./L和1.01mg/L.哲水蚤的密度最大值(20.0ind./L)出现在2005年4月,而剑水蚤(21.7ind./L)出现在2005年8月.无节幼体在各月份均有较高密度,其最高密度(46.6ind./L)和生物量(0.14mg/L)出现在2006年3月.温度和浮游植物是影响南湖浮游甲壳动物群落结构季节变化的重要因素. 相似文献
8.
南京玄武湖浮游甲壳动物的水平分布及其与环境的关系 总被引：1，自引：1，他引：0
于2010年7月对玄武湖三个区域(荷花区、湖岸区、敞水区)的浮游甲壳动物水平分布进行了分析,并探讨了浮游甲壳动物种类、丰度分布与环境因子的关系.结果显示:荷花区、湖岸区、敞水区的氮磷营养盐浓度无显著差异,三个区域pH逐渐变高.相比其他区域,荷花区叶绿素a浓度最高而总悬浮质浓度最低.荷花区浮游甲壳动物丰度显著高于敞水区和湖岸区.全湖枝角类优势种为模糊秀体溞、微型裸腹溞、尖额溞以及壳纹船卵溞.桡足类的优势种为北碚中剑水蚤和台湾温剑水蚤.与其他湖区相比,荷花区浮游甲壳动物种类最多,且检出缺刺新秀体溞等稀有枝角类.冗余分析(RDA)表明与玄武湖浮游甲壳动物优势种分布相关的重要环境因子为总悬浮质、叶绿素a和总溶解磷浓度.结合浮游甲壳动物种类、丰度分布及环境因子分析得出,模糊秀体溞更倾向于分布在敞水区,而荷花区为其余大部分浮游甲壳动物种类提供了合适的生存条件. 相似文献
9.
比较分析了我国南亚热带湖库7种常见浮游动物,萼花臂尾轮虫(Brachionus calyciflorus)、前节晶囊轮虫(Asplanchna priodonta)、颈沟基合溞(Bosminopsis deitersi)、微型裸腹溞(Moina micrura)、中华拟同型溞(Daphnia similoides sinensis)、温中剑水蚤(Mesocyclops thermocyclopoides)和舌状叶镖水蚤(Phyllodiaptomus tunguidus)在温度15~30℃范围内的氮、磷排泄率以及氮、磷含量.氮、磷含量分别为4.9~24.2μg/mg(DW)和51.2~153.5μg/mg(DW);氮磷原子比为11.5~43.0.磷含量与个体干重呈显著正相关关系,但氮含量和氮磷比与个体干重相关性不显著.溶解态无机磷(DIP)排泄率为0.31~2.05μg/(mg(DW)·h),与个体干重呈显著负相关,与温度和个体氮磷含量比值均呈显著正相关.总溶解态氮(TDN)排泄率为24~256μg/(mg(DW)·h),与温度和个体干重均呈显著相关,但与个体氮磷含量比值相关性不显著.排泄的TDN∶DIP原子比为112~352,与温度呈显著正相关,与个体干重和氮磷含量比值均呈显著负相关.结果表明,在高氮磷比的食物条件下,7种浮游动物营养盐排泄均呈现高的氮磷比特征,磷排泄率和排泄的氮磷比的种间差异受个体干重和个体氮磷比影响. 相似文献
10.
枝角类溞会由于捕食者的存在而发生形态、行为、生活史等的变化.通过为期10 d对太湖春、夏季优势种同形溞(Daphnia similis)在有幽蚊幼虫(CL)、无幽蚊幼虫(CK)及培养过幽蚊幼虫的过滤水(FL)3个环境水平的模拟实验,发现同形溞在有幽蚊幼虫和培养过幽蚊幼虫的过滤水处理下平均体长、累积产仔数及平均产仔数均显著大于无幽蚊幼虫组,表明幽蚊幼虫释放的信息素能改变同形溞的体长、产仔数等生活史参数,这种改变会降低同形溞被捕食的风险.说明在自然环境下,幽蚊幼虫等无脊椎捕食者能通过直接捕食和信息素的间接作用共同影响枝角类种群. 相似文献
11.
于2000年丰水期和枯水期调查了广东省19座典型大中型水库枝角类,随后对其中3座代表性水库进行了4年的枝角类种类定性调查.在鉴定出的枝角类16属24种中有13个广温种、7个嗜暖种、3个嗜寒种和1个特有种;每个水库的平均种类数5-6种.从个体大小来看,水库枝角类以小个体种类为主,有14种的体长小、于1 mm,它们分布广且数量多,其中优势种主要为长额象鼻溞、秀体溞、微型裸腹溞、颈沟基合溞和角突网纹溞等.透明溞和透明薄皮溞是主要的大个体种类,出现在4座贫、中营养水库的水样中.水库枝角类的丰度较低,在丰水期,平均丰度小于10 ind./L和10-20 ind./L的水库分别为14座和5座,在枯水期,为12座和5座,而高州水库和河溪水库中的平均丰度达67ind./L.主要优势种在不同营养类型水库中分布差别不大.枝角类的丰度受水力滞留时间影响,直流型水库的枝角类种群丰度的分布明显受到水流速度的影响,湖泊区枝角类个体及其食物均随水库放水输出而减少.由于采样点主要位于大坝附近,枝角类以敞水区的种类为主.从种类组成和数量来看,广东省水库枝角类具有明显的热带特点,枝角类的生物量小,以个体较小的种类优势种,大型种类的个体数量极低且身体透明. 相似文献
12.
热带水库敞水区轮虫种类组成与数量结构——基于海南7座典型水库的分析 总被引：4，自引：4，他引：0
海南省是我国典型的热带区域,目前对该地区浮游动物的研究和报道极少.为了解该地区轮虫的群落组成,于2006年12月和2007年5月对分布于海南省7座典型的水库敞水区进行了采样调查.共采集到轮虫32种,多为营浮游性生活的广温性和嗜温性种类.在不同时期,水库具体优势种类及其相对优势度有一定差别,主要优势种个体较小且有被甲.在丰水期,剪形臂尾轮虫和镰状臂尾轮虫为主要优势种,在枯水期则以柬隐三肢轮虫为主要优势种.海南省7座水库的平均丰度和生物量分别为66.8ind./L和21.6μg/L,均远低于亚热带和温带地区.总体上,海南省水库敞水区轮虫呈现出种类少、个体小、丰度低的特点.尽管两次采样期间的轮虫优势种的相对丰度存在一定变化,但轮虫的种类组成结构相对一致,反映出该地区水库轮虫的群落结构具有较高稳定性. 相似文献
13.
舌状叶镖水蚤(Phyllodiaptomus tunguidus)是我国特有的大型哲水蚤,主要分布在我国华南地区.根据2000年对广东省19座典型大中型水库的2次采样和2002年对流溪河水库和新丰江水库的5次采样,重点测定了流溪河水库、新丰江水库和鹤地水库等3座大型水库中舌状叶镖水蚤个体体长及形态参数,分析了广东省大中型水库中舌状叶镖水蚤的种群与个体大小的分布特征.在对19座水库的2次采样中,11座水库发现该种成体,其中5座水库在丰水期没有出现该种的成体,6座水库在丰水期和枯水期都有该种类成体的出现.丰水期与枯水期舌状叶镖水蚤的平均丰度分别为0.465ind./L和0.996ind./L.舌状叶镖水蚤主要出现在大型水库中,特别是贫营养的大型水库,其丰度主要由食物数量、质量与捕食压力所决定.2002年,流溪河水库丰度和新丰江水库舌状叶镖水蚤全年的平均值为1.308ind./L和0.294ind./L,丰水期高于枯水期.在个体大小和形态特征上,2座贫营养水体——流溪河水库、新丰江水库的舌状叶镖水蚤的体长与第一触角长度均大于中营养水体——鹤地水库,这种形态上的差异是由鱼类捕食方式(滤食或选择性捕食)所决定. 相似文献
14.
Tadesse Dejenie Steven A.J. Declerck Tsehaye AsmelashSarah Risch Joachim Mergeay Tom De BieLuc De Meester 《Limnologica》2012,42(2):137-143
A field survey of zooplankton communities was carried out in 32 recently established tropical semi-arid reservoirs in the highlands of Northern Ethiopia with the aim to identify to what extent environmental factors determine species composition of the cladoceran community in such isolated and young reservoirs. To address seasonal variation, the survey was carried out both at the beginning and the end of the dry season. A total of 15 species of cladocerans were identified. Daphnia was the most abundant cladoceran genus, and was present in all reservoirs. Using presence-absence data, no association between cladoceran community composition and geographic distance was found. RDA results indicate that the set of environmental variables that explained cladoceran community composition differed among seasons. Depth, altitude and fish biomass showed a significant association with cladoceran community composition during the wet season, whereas variation in cladoceran community structure was associated with phytoplankton biomass in the dry season. The relative abundance of Daphnia was much higher in the pelagic than in the littoral zone of our study systems. Two key groups of pelagic filter-feeding cladocerans, Diaphanosoma and Daphnia, showed a clear pattern, in which one or the other tended to strongly dominate the community. In addition, we observed a negative association between dominance of Daphnia in the zooplankton community and dominance of cyanobacteria in the phytoplankton community. 相似文献
15.
Reproductive seasonality of the fish fauna and limnoecology of semi-arid Brazilian reservoirs 总被引：1，自引：1，他引：0
Sathyabama Chellappa Regina M.X. Bueno Thiago Chellappa Naithirithi T. Chellappa Vera Maria Fonseca Almeida e Val 《Limnologica》2009,39(4):325-329
The native fish fauna commonly found in the drainage basins of rivers and reservoirs of Latin America, including those of the semi-arid Northeastern Brazil, are representatives of the Neotropical region. This work reports on the reproductive ecology of five commercially important and consumable native fish species, in relation to rainfall and hydrological variables of the semi-arid reservoirs in Brazil. Pluviometric precipitation, temperature, pH, dissolved oxygen and electrical conductivity of the water were registered, and maturation of fish gonads was assessed on a monthly basis. This region is characterized with short spells of rain interspersed with long dry season and rainfall seems to be the main environmental factor which modulates the timing of the spawning period of fish. Construction of reservoirs without adequate facilities for fish migration has an adverse impact on the migratory fish species which are of commercial and ecological importance to semi-arid Northeastern Brazil. 相似文献
16.
Species diversity and distribution for phytoplankton of the Pearl River estuary during rainy and dry seasons 总被引：11，自引：0，他引：11
Huang L Jian W Song X Huang X Liu S Qian P Yin K Wu M 《Marine pollution bulletin》2004,49(7-8):588-596
Based on data collected at 31 stations and 1 continuous station in the Pearl River estuary during cruises of July 1999 (rainy season) and January 2001 (dry season), this study examined taxonomic composition, abundance, and spatial distribution of phytoplankton. Results indicated 130 species of phytoplankton in the samples from the rainy season, and 132 species in the dry season. Among them, in the rainy season, 82 species of diatom, 39 fresh-water and half-fresh-water species and 41 species of red tide organisms were found. Within these, there were 54 tropical and sub-tropical species, 47 cosmopolitan species and 17 temperate species. The abundance of phytoplankton in the rainy season was higher than that of the dry season, with an average of 6.3 x 10(5) cells x L(-1) and 1.4 x 10(5) cells x L(-1), respectively. Diversity index (H') and evenness (J) were 2.47 and 0.57 in the rainy season, and 2.01 and 0.54 in the dry season. The dominant phytoplankton species in the rainy season was Skeletonema costatum with an average of 2.8 x 10(5) cells x L(-1) and 45.0% of the total phytoplankton abundance. In the dry season, Eucampia zoodiacus became the key dominant species (5.9 x 10(4) cells x L(-1)) when it was 43.47% of the total phytoplankton abundance. Distribution of the dominant species varied with salinity of sea-water, and their amounts correlated negatively with nutrients and zooplankton. 相似文献
17.
东江流域在广东省政治、经济和社会中占有重要地位,域内新丰江、枫树坝和白盆珠3大水库的来水量直接影响区域生产生活供水.面对水库群联合调度新要求,本文利用Copula函数构建了3大水库入库流量的二维和三维联合分布,分析其丰枯遭遇概率,主要结论如下:(1)3大水库两两间丰枯同步的概率大于丰枯异步的概率,非汛期丰枯同步的概率大于汛期.其中,白盆珠与新丰江、枫树坝丰枯异步的概率相对较大,这为其与另两个水库丰枯互补提供了可能;(2)三维联合分布显示,3大水库丰枯同步的概率在全年、汛期和非汛期均较大,依次为42.29%、41.74%和51.99%,其中同丰和同枯的概率远大于同平的概率.枫树坝与新丰江对下游具有补偿能力的概率分别为29.81%和23.03%,不具有补偿能力的概率分别为32.75%和22.32%;(3)利用3大水库的联合分布,可获得各水库不同入库流量遭遇的概率以及特定概率下各水库入库流量的可能组合,对3大水库联合优化调度具有重要的理论与实践价值. 相似文献
18.
Xinjun Tu Qiang Zhang Vijay P. Singh Xiaohong Chen Chun-Ling Liu Shao-Bo Wang 《Stochastic Environmental Research and Risk Assessment (SERRA)》2012,26(6):823-834
Due to the influence of climate change and human activities, more and more regions around the world are nowadays facing serious water shortages. This is particularly so with the Guangdong province, an economically prosperous region in China. This study aims at understanding the abrupt behavior of hydrological processes by analyzing monthly precipitation series from 257 rain gauging stations and monthly streamflow series from 25 hydrological stations using the likelihood ratio statistic and schwarz information criterion (SIC). The underlying causes of the changing properties of hydrological processes are investigated by analyzing precipitation changes and information of water reservoirs. It is found that (1) streamflow series in dry season seems to exhibit abrupt changes when compared to that in the flood season; (2) abrupt changes in the values of mean and variance of hydrological variables in the dry season are more common than those in the streamflow series in the flood season, which implies that streamflow in the dry season is more sensitive to human activities and climate change than that in the flood season; (3) no change points are identified in the annual precipitation and precipitation series in the flood season. Annual streamflow and streamflow in the flood season exhibit no abrupt changes, showing the influence of precipitation on streamflow changes in the flood season. However, streamflow changes in the dry season seem to be heavily influenced by hydrological regulations of water reservoirs. The results of this study are of practical importance for regional water resource management in the Guangdong province. 相似文献
19.
枯水期咸潮入侵已经严重威胁到了感潮河流区域供水安全.本文通过构建避咸蓄淡供水模型,耦合了咸度预测、河库联合供水调度和供水安全分析模块,为依赖感潮河流为水源地的区域供水安全管理提供了一种整体思路和决策方法.以面向粤港澳大湾区珠海东部及澳门的珠江三角洲磨刀门水道取供水为例,基于潮汐、径流和风等因子及咸度实测数据,较好地拟合了基于BP神经网络的咸度预测模型,及含氯度与超标时间的曲线函数,建立了上游来水和咸度超标时间之间的联系,得到了避咸蓄淡取水时机.咸度预测与当地河库联合供水调度相结合,得到了上游枯水期来水过程的当地区域供需平衡状况.枯水期不考虑水库调蓄的资源性缺水临界需水量为3.22亿m3,水库参与调蓄的工程性缺水临界需水量为3.75亿m3.通过供水安全分析模块,基于设定的风险阈值和临界阈值识别出了不同需水规模的上游来水临界流量特征.对于当地规划的需水规模4.23亿m3,期望上游枯水期临界流量均值约为3372 m3/s.整体上来说,需水规模越大,对上游来水期望的临界流量越大,但同时还与枯水期流量分布有关. 相似文献
20.
Łukasz Wiejaczka Małgorzata Kijowska-Strugała Paweł Pierwoła Mariusz Nowak 《Water Resources》2018,45(6):861-872
The article presents the spatial and temporal dynamics of water temperature in two reservoirs on the upper course of the Dunajec River in the Polish Carpathians. It aims at presenting how spatial patterns and time evolution of water temperature in the reservoirs affect the water temperature in the river. The analysis is based on the results of water temperature measurements in hydrometric verticals in two reservoirs as well as in the river upstream and downstream of the reservoirs. The measurements were carried out in 2012 and 2013, in hydrometeorological conditions typical for each season of the year. Based on the measurements, it has been demonstrated that the complex of reservoirs affects the water temperature in the river over the year and the existence of the smaller lower reservoir may attenuate the cooling or heating effect of the main reservoir on the river. 相似文献