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1.
闫云君  李晓宇 《生态科学》2006,25(2):97-101
大型底栖动物在河流生态系统中发挥着重要作用。2003年6月至2004年6月间对汉江流域2级河流--黑竹冲河大型底栖动物群落优势种类的生产力进行了为期一周年的调查研究。结果表明,主要优势种小裳蜉(Leptophlebia sp.)和蜉蝣(Ephemera sp.)的生活史均为一年两代,蜉蝣的两个代之间界限比较明显;小裳蜉成虫羽化主要发生在秋季和冬季,而蜉蝣成虫羽化主要发生在夏季和冬季。小裳蜉和蜉蝣种群的生物量和多度均出现两次峰值。采用体长频率法(size-frequencymethod)测算的周年生产量分别为:小裳蜉,38.0362g·m-2·a-1,P/B为11.4;蜉蝣,76.0318g·m-2·a-1,P/B为11.8。  相似文献   

2.
闫云君  李晓宇 《生态科学》2006,25(4):308-311
大型底栖动物在河流生态系统中发挥着重要作用,2003年6月至2004年6月间对汉江流域2级河流--黑竹冲河大型底栖动物群落优势种类的生产力进行为期一周年的调查研究,并对其生产量的营养基础进行了初步分析,结果表明,主要优势种蚋(Simuliumsp.)的生活史为一年一代,成虫羽化主要发生在冬季;种群生物量和多度在12月到峰值,分别为115ind·m-2,250.9mg·m-2;采用龄期频率分布法(size-frequencymethod)测算的周年生产量为3.9216g·m-2·a-1,P/B为4.6.在其前肠内含物中,无形态碎屑、真菌和硅藻所占比例分别为60.40%、3.91%和35.96%,对生产量的贡献率分别为:32.2%、10.4%和57.4%.  相似文献   

3.
胜利河连续系统中蜉蝣优势种的生产量动态和营养基础   总被引:1,自引:0,他引:1  
大型底栖动物在河流生态系统中发挥着重要作用, 2009 年3月至2010 年3月间对长江中游支流巴河流域的胜利河大型底栖动物群落优势种类的生产力进行为期1 周年的调查研究, 结果表明, 主要蜉蝣优势种扁蜉、等蜉和红斑蜉的生活史为3代/年、3代/年和 2代/年。现存量呈现出1-3级河流增加,而4级又较3级有所下降的趋势。采用龄期频率法( instar-frequency method) 测算的平均周年生产量分别为扁蜉, 200.13 g/(m2.a) , P/B 为23.69; 等蜉, 82.06 g/(m2.a), P/B 为18.12;红斑蜉, 12.30 g/(m2.a), P/B 为8.78。三种蜉蝣的生产量动态在时间上与现存量动态较一致,但彼此各不相同。扁蜉的日均产量于2009年3月在二级河流中达到最大(363.56 mg/m2.d),等蜉于2010年3月在三级河流中到达最大(282.76 mg/m2.d),而红斑蜉于2009年3月在一级河流中到达最大(33.36 mg/m2.d)。生产量的营养基础分析结果表明,扁蜉前肠内含物中无形态碎屑、动物组织、植物纤维、丝状藻类、硅藻所占平均比例为74.37%,4.19%,17.11%,4.29%,0.04%,对生产量的贡献率分别为77.15%,11.27%,6.57%,4.95% ,0.04%;等蜉前肠内含物中无形态碎屑、动物组织、植物纤维、真菌、丝状藻类和硅藻所占平均比例为65.64%,6.17%,23.04%,0.54%,4.53%,对生产量的贡献率分别为: 68.16%,16.61%,8.86%,1.03%,5.23%,0.09%,0.10%;红斑蜉前肠内含物中,无形态碎屑、动物组织、植物纤维、真菌、丝状藻类和硅藻所占平均比例为41.14%,5.96%,38.04%,1.34%,11.21%,2.31%,对生产量的贡献率分别为46.67%,17.52%,15.98%,2.81%,14.13%,2.91%。这与我们在黑竹冲和叹气沟的研究结果存在一定差异,可能与这些溪流自身环境和地区分布有关。  相似文献   

4.
汉江流域黑竹冲河部分优势大型底栖动物的周年生产量   总被引:3,自引:1,他引:2  
大型底栖动物在河流生态系统中发挥着重要作用,2003年6月至2004年6月间对汉江流域2级河流——黑竹冲河大型底栖动物群落优势种类的生产力进行为期一周年的调查研究,结果表明,主要优势种纹石蛾(Hydropsyche sp.)、扁蜉(Ecdyrus sp.)和细蜉(Caenissp.)生活史均为一年两代,河蚬(Corbicula fluminea)基本为三年一代。纹石蛾种群现存量在1月达到峰值,河蚬种群多度在3月、6—9月保持较高水平,生物量在10月达到峰值,而扁蜉种群的生物量和多度分别在4月和6月达到峰值,细蜉的生物量和多度则分别2月和6月达到峰值。采用龄期频率分布法(size-frequency method)测算的周年生产量(湿重或带壳湿重)和P/B系数分别为:纹石蛾,267.464g/m^2.a,P/B为9.8;河蚬,783.1g/m^2.a,P/B系数为2.3;扁蜉,267.46g/m^2.a,P/B为15.4;细蜉,53.60g/m^2.a,P/B为9.4。  相似文献   

5.
闫云君  李晓宇 《生态学报》2005,25(12):3127-3132
大型底栖动物在河流生态系统中发挥着重要作用,2003年6月至2004年6月间对汉江流域2级河流--黑竹冲河大型底栖动物群落优势种类的生产力进行为期1周年的调查研究,结果表明,主要优势种杂色特维摇蚊(Tvetenia discoloripes Goetghebuer)和波特真开氏摇蚊(Eukiefferiella potthasti Lehmann)的生活史均为1年1代.杂色特维摇蚊种群现存量在1年中出现1次峰值,波特真开氏摇蚊则出现3次.采用龄期频率法(1nstar-frequency method)测算的周年生产量分别为杂色特维摇蚊,120.3058g/(m2·a),P/B为10.5;波特真开氏摇蚊,17.7554g/(m2·a),P/B为11.4.两种摇蚊的生产量动态在时间上重叠程度较大,比例相似性系数达0.63,重叠现象主要发生在冬春季节.杂色特维摇蚊前肠内含物中,无形态碎屑、真菌和硅藻所占平均比例为95.81%,0.52%和3.67%;对生产量的贡献率分别为87.56%,2.38%和10.06%;波特真开氏摇蚊前肠内含物中,无形态碎屑、真菌和硅藻所占比例分别为93.48%,0.68%和5.84%,对生产量的贡献率分别为81.71%,2.97%和15.32%.  相似文献   

6.
叹气沟河优势摇蚊种群动态、周年生产量及营养基础   总被引:3,自引:0,他引:3  
2006年4月-2007年3月对清江流域二级河流叹气沟河大型底栖动物群落中摇蚊优势种进行了为期1周年的调查。结果表明:主要优势摇蚊斑特突摇蚊(Thienemanimyia lentiginosa)、波特真开氏摇蚊(Eukiefferiella potthasti)和拟长跗摇蚊(Paratanytarsus panhenogeneticu)的生活史均为1年2代;拟长跗摇蚊、斑特突摇蚊的种群密度6月、9月和翌年3月出现峰值,波特真开氏摇蚊则在5月和翌年1月出现峰值;采用龄期频率法(instar-fre-quency method)测算的周年生产量(湿质量)和生产量(P)/生物量(B)分别为斑特突摇蚊17.44g·m^-2、3.4,波特真开氏摇蚊1.66g·m^-2、2.3,拟长跗摇蚊3.3g·m^-2、6.4;3种摇蚊的生产量在时间动态上重叠程度较大,主要发生在春季;通过对3种摇蚊的前肠内含物分析,测算了各类食物的比例及其对生产量的贡献率,结果表明,无形态碎屑为主要食物类型,占前肠内含物的73.27%-86.89%,而斑特突摇蚊生产量则主要来源于动物性食物的贡献率(51.64%)。  相似文献   

7.
2006年4月至2007年3月间对清江流域二级河流-胡家溪大型底栖动物群落的优势种中华新米虾Neocaridina denticulata sinensis(Kemp)进行为期1周年的调查研究。结果表明,中华新米虾的生活史为1年2代,中华新米虾的种群密度峰值分别出现在7月(31ind/m2)、10月(35ind/m2)、12月(20ind/m2)和次年的2月(20ind/m2),生物量峰值则出现在4月(1.76g/m2)、7月(4.74g/m2)和次年2月(2.38g/m2)。采用体长频率法(Size-frequency method)测算的周年生产量和P/B分别为67.40g/m2(湿重)和4.7。通过对中华新米虾前肠内含物组成的分析测定了各类食物类型的比例及对生产量的贡献率,结果表明,无形态碎屑和动物组织为其主要食物类型,分别占前肠内含物的79.9%和12.5%,对生产力的贡献率分别为62.50%和34.18%。    相似文献   

8.
2006年4月-2007年3月间,对长江支流清江二级支流——胡家溪大型底栖动物群落结构和生产量进行为期一年的调查.结果表明,主要优势摇蚊Conchapelopia sp.的生活史为一年两代,波特真开氏摇蚊(Eukiefferiella potthasti)为一年一代;Conchapelopia sp.的年均密度和年均生物量分别为105 ind·m-2、0.1g·m-2,波特真开氏摇蚊为280ind·m-2、0.3g·m-2.采用龄期频率法测算的周年生产量(g·m-2湿重)和生产量/生物量(P/B),Conchapelopia sp.分别为1.2g·m-2、2.3,波特真开氏摇蚊为1.4g·m-2、2.5.2种摇蚊的生产量时间重叠比例相似系数为0.7,重叠主要出现在冬春季节.营养基础分析发现,无形态碎屑为2种摇蚊的主要食物,占其组成的84%以上,对生产量的贡献率分别为80.1%、68.6%.2个优势种的年均物质通量分别为7.2和7.1g·m-2.  相似文献   

9.
王强  袁兴中  刘红 《生态学报》2012,32(21):6726-6736
浅滩和深潭是山地河流中常见的河流生境结构。2011年7月,在重庆开县东河上游双河口-杉木桥河段,选择21个浅滩和深潭,调查大型底栖动物,研究影响不同生境中底栖动物组成、分布和多样性的生态机理。结果表明:调查河段浅滩和深潭中大型底栖动物分别为31种和24种,密度分别为450.62 个/m2和86.24 个/m2,生物量分别为2.88 g/m2和0.55 g/m2。浅滩有指示种11种,即纹石蛾(Hydropsyche sp.)、假蜉(Iron sp.)、假二翅蜉(Pseudocloeon sp.)、舌石蛾(Glossosoma sp.)、高翔蜉(Epeorus sp.1)、背刺蜉(Notacanthurus sp.)、Heterocloeon sp、锯形蜉(Serratella sp.)、朝大蚊(Antocha sp.)、等蜉(Isonychia sp.)、溪颏蜉(Rhithrogena sp.)。深潭指示种仅蜉蝣(Ephemera sp.)和黑大蚊(Hexatoma sp.)两种。刮食者为两类生境的优势功能摄食类群。浅滩中滤食者和刮食者比例显著高于深潭,而收集者和捕食者显著低于深潭。两类生境中大型底栖动物群落结构差异显著。浅滩中大型底栖动物的密度、生物量、丰富度指数、Shannon-Wiener 指数、改进的Shannon-Wiener指数均明显高于深潭。受地貌形态、水力特征和冲淤变化规律影响的生境稳定性和异质性差异是导致大型底栖动物群落差异的主要原因。  相似文献   

10.
作为长江上游唯一未在干流建坝的一级支流和长江上游珍稀特有鱼类国家级自然保护区的核心区,赤水河流域孕育和保护了极为丰富的底栖动物多样性。然而对赤水河底栖动物的了解仍不充分,缺乏涵盖整个流域的连续性、季节性的底栖动物调查。本研究于2019–2021年按季度开展4次调查,系统评估了赤水河水系底栖动物物种多样性,更新了物种名录,甄别出其驱动机制及受胁因素,并提出相应的保护对策。本次调查共记录底栖动物5门9纲22目86科186属209种。全流域优势种均为昆虫类,如蜉蝣属一种(Ephemera sp.)、扁蜉属一种(Heptagenia sp.)、河花蜉属一种(Polamanthus sp.)、四节蜉属一种(Baetis sp.)、潜水蝽科一种(Naucoridae sp.)和多足摇蚊属一种(Polypedilum sp.)。春季底栖动物的物种丰富度、Shannon-Wiener多样性指数、Simpson优势度指数、Pielou均匀度指数均高于其他季节。上游的密度、物种丰富度、Shannon-Wiener多样性指数和Simpson优势度指数均明显高于中下游。主坐标分析显示,不同季节和不同河段间底栖...  相似文献   

11.
12.
《Trends in microbiology》2023,31(8):872-873
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13.
Evidence from numerical taxonomic analysis and DNA-DNA hybridization supports the proposal of new species in the genera Actinobacillus and Pasteurella. The following new species are proposed: Actinobacillus rossii sp. nov., from the vaginas of postparturient sows; Actinobacillus seminis sp. nov., nom. rev., associated with epididymitis of sheep; Pasteurella bettii sp. nov., associated with human Bartholin gland abscess and finger infections; Pasteurella lymphangitidis sp. nov. (the BLG group), which causes bovine lymphangitis; Pasteurella mairi sp. nov., which causes abortion in sows; and Pasteurella trehalosi sp. nov., formerly biovar T of Pasteurella haemolytica, which causes septicemia in older lambs.  相似文献   

14.
Ten Bifidobacterium strains, i.e., 6T3, 64T4, 79T10, 80T4, 81T8, 82T1, 82T10, 82T18, 82T24, and 82T25, were isolated from mantled guereza (Colobus guereza), Sumatran orangutan (Pongo abeli), silvery marmoset (Mico argentatus), golden lion tamarin (Leontopithecus rosalia), pied tamarin (Saguinus bicolor), and common pheasant (Phaisanus colchinus). Cells are Gram-positive, non-motile, non-sporulating, facultative anaerobic, and fructose 6-phosphate phosphoketolase-positive. Phylogenetic analyses based on the core genome sequences revealed that isolated strains exhibit close phylogenetic relatedness with Bifidobacterium genus members belonging to the Bifidobacterium bifidum, Bifidobacterium longum, Bifidobacterium pullorum, and Bifidobacterium tissieri phylogenetic groups. Phenotypic characterization and genotyping based on the genome sequences clearly show that these strains are distinct from each of the type strains of the so far recognized Bifidobacterium species. Thus, B. phasiani sp. nov. (6T3 = LMG 32224T = DSM 112544T), B. pongonis sp. nov. (64T4 = LMG 32281T = DSM 112547T), B. saguinibicoloris sp. nov. (79T10 = LMG 32232T = DSM 112543T), B. colobi sp. nov. (80T4 = LMG 32225T = DSM 112552T), B. simiiventris sp. nov. (81T8 = LMG 32226T = DSM 112549T), B. santillanense sp. nov. (82T1 = LMG 32284T = DSM 112550T), B. miconis sp. nov. (82T10 = LMG 32282T = DSM 112551T), B. amazonense sp. nov. (82T18 = LMG 32297T = DSM 112548T), pluvialisilvae sp. nov. (82T24 = LMG 32229T = DSM 112545T), and B. miconisargentati sp. nov. (82T25 = LMG 32283T = DSM 112546T) are proposed as novel Bifidobacterium species.  相似文献   

15.
A previous phylogenetic study on type strains of the genus Micromonospora and Micromonospora species bearing non-validly published names has pointed towards the species status of several of latter strains. Subsequent studies on morphological, cultural, chemotaxonomic, metabolic, and genomic properties, and on whole cell mass spectrometric analyses by matrix adsorbed laser desorption/ionization time-of-flight (MALDI-TOF) confirmed the species status, leading to the proposal of eight new Micromonospora species: Micromonospora citrea sp. nov., type strain DSM 43903T, Micromonospora echinaurantiaca sp. nov., type strain DSM 43904T, Micromonospora echinofusca sp. nov., type strain DSM 43913T, Micromonospora fulviviridis sp. nov., type strain DSM 43906T, Micromonospora inyonensis sp. nov., type strain DSM 46123T, Micromonospora peucetia sp. nov., type strain DSM 43363T, Micromonospora sagamiensis sp. nov., type strain DSM 43912T and Micromonospora viridifaciens sp. nov., type strain DSM 43909T.  相似文献   

16.
《Mycoscience》2014,55(4):299-307
Minimelanolocus bicolorata sp. nov., Paradendryphiopsis elegans sp. nov. and Corynesporella bannaense sp. nov., are described and illustrated. Minimelanolocus bicolorata is unique in possessing the schizolytic conidial secession and solitary, acropleurogenous, holoblastic conidia that are ellipsoidal, 3-euseptate, 30–35 × 7.5–9.5 μm, verruculose, pale brown, with an appendage at each end. Paradendryphiopsis elegans is characterized by monoblastic conidiogenous cells producing short chains of conidia that are 13–30.5 × 4–6.5 μm, 2–3-euseptate and fusiform to obclavate. Corynesporella bannaense is distinguished by terminal and integrated or discrete, monotretic conidiogenous cells that arise as lateral branches from the tip of the conidiophore and solitary conidia that are 12–16-distoseptate, smooth, obclavate, thick-walled, pale brown, and 100–140 × 10–14 μm. Keys to species of Minimelanolocus, Paradendryphiopsis and Corynesporella are provided.  相似文献   

17.
Three new species of Candida and a new species of Trigonopsis are described based on their recognition from phylogenetic analysis of gene sequences from large subunit ribosomal RNA, ITS1/ITS2 rRNA, mitochondrial small subunit rRNA and cytochrome oxidase II. Candida infanticola sp. nov. (type strain NRRL Y-17858, CBS 7922) was isolated from the ear of an infant in Germany and is closely related to Candida sorbophila. Candida polysorbophila sp. nov. (type strain NRRL Y-27161, CBS 7317) is a member of the Zygoascus clade and was isolated in South Africa as a contaminant from an emulsion of white oil and polysorbate. Candida transvaalensis sp. nov. (type strain NRRL Y-27140, CBS 6663) was obtained from forest litter, the Transvaal, South Africa, and forms an isolated clade with Candida santjacobensis. Trigonopsis californica sp. nov. (type strain NRRL Y-27307, CBS 10351) represents a contaminant from wine in California, and forms a well-supported clade with Trigonopsis cantarellii, Trigonopsis variabilis and Trigonopsis vinaria.  相似文献   

18.
Summary Versatility of gene transfer by transconjugation in marine cyanobacteria was demonstrated. In this study, seven different marine cyanobacteria were used as recipient cells. First, transconjugation was carried out using the mobilizable transposon (Tn5) carrying plasmid pSUP1021. Transconjugants were observed in all marine cyanobacteria tested. Second, the broad-host-range vector pKT230 (IncQ) was tested for transconjugation. pKT230 has been successfully transferred in a marine cyanobacterium Synechococcus sp. NKBG15041C, and replicated as an autonomous replicon without alteration in the restriction enzyme pattern. A maximum transfer efficiency of 5.2 × 10–4 transconjugants/recipient cell was observed, when mating was performed on agar plates containing low salinity (0.015 m NaCl) medium. This is the first study to demonstrate gene transfer in marine cyanobacteria via transconjugation. Correspondence to: K. Sode  相似文献   

19.
This work deals with the taxonomic study of 12 orange-pigmented bacteria isolated from permafrost sediments, rice plots, and soils contaminated with wastes from the chemical and salt industries, which were assigned to the genus Brevibacterium on the basis of phenotypic characteristics, as well as of some strains described previously as Brevibacterium linens. The study revealed three genomic species, whose members and the type strains of the closest species of Brevibacterium had DNA similarity levels between 24 and 59%. The strains of the genomic species differed from each other and from the known species of Brevibacterium in some physiological and biochemical characteristics, as well as in the sugar and polyol composition of their teichoic acids. The 16S rDNA sequence analysis confirmed the assignment of the environmental isolates to the genus Brevibacterium and showed the phylogenetic distinction of the three genomic species. The results obtained in this study allow three new Brevibacterium species to be described: Brevibacterium antiquum (type strain VKM Ac-2118T = UCM Ac-411T), Brevibacterium aurantiacum (type strain VKM Ac-2111T = NCDO 739T = ATCC 9175T), and Brevibacterium permense (type strain VKM Ac-2280T = UCM Ac-413T).  相似文献   

20.
苜蓿、草木樨、锦鸡儿根瘤菌的表型多样性分析   总被引:23,自引:1,他引:22  
选用48株分离自新疆和内蒙的苜蓿属、草木樨属、锦鸡儿属植物的根瘤菌菌株, 进行了营养利用、抗生素抗性、耐逆性和酶活性测定等133个表型性状分析。发现分离自同种寄主植物的根瘤菌由于地理来源的不同而存在着较大的多样性。通过数值分类,各已知种分别聚群,41株未知菌在85%的相似水平上分为3个不同于已知种的群。群1的菌株主要分自苜蓿,群2的菌株主要分自草木樨,群3的菌株分自锦鸡儿,XJ96 333(寄主为Melilotus)作为1个单株在84%的相似水平上和群1聚在一起。NM 020(寄主为Caragana)在88%的相似水平上和R.leguminosarum聚在一起; NM 183、NM 218(寄主为Caragana)在86%的相似水平上和S.fredii聚在一起; 在67%的相似水平上, XJ96 482(寄主为Medicago sativa)和其它所有供试菌株聚群。群1、2、3的所有菌株能在含2.0%(340 mM)NaCl的YMA培养基上、pH 9.0的YMA培养基、40℃的高温下生长; 群3的所有菌株还能在含3.0%(510 mM)NaCl的YMA培养基上生长;群1中90%的菌株和群2、3的所有菌株能在10℃的低温下生长。 表明群1、2、3的菌株具有较强的耐盐碱、耐高低温的特性。和已知种S.meliloti具有相同寄主的群1、群2在85%相似水平上未和S.meliloti聚群,表现了这两群菌在表型上的多样性。  相似文献   

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