巢湖及其支流浮游动物群落结构特征及水质评价

2013年9月至2014年6月对巢湖及柘皋河、杭埠河、南淝河3条支流的浮游动物进行了调查,共检出浮游动物297种,其中,原生动物124种,轮虫135种,枝角类29种,桡足类9种。南淝河浮游动物物种数最多,为203种,巢湖最少,为130种;巢湖及3条支流均以原生动物和轮虫物种数最多。浮游动物总密度为644 223 ind/L,柘皋河浮游动物密度最高,巢湖浮游动物密度最低,巢湖及3条支流原生动物密度占浮游动物总密度的比例均为最高;四个季节柘皋河浮游动物密度均为最高。浮游动物总生物量为253.14 mg/L,南淝河浮游动物生物量最高,杭埠河和巢湖浮游动物生物量较低;春季和冬季柘皋河浮游动物生物量最高,夏季和秋季南淝河浮游动物生物量最高。相较3条支流,巢湖浮游动物优势种数最少。依据理化指标,巢湖及3条支流为富营养或超富营养水平,营养水平为:南淝河巢湖柘皋河杭埠河。浮游动物群落结构和环境因子的冗余分析(RDA)表明,巢湖及3条支流浮游动物群落结构在四个季节均未能明显区分开,浮游动物群落和环境理化因子的相关性较小。     

鄱阳湖流域非繁殖期鸟类多样性

2010年11月-2011年3月,采用样线和样点法相结合,对鄱阳湖流域非繁殖期鸟类种类及数量进行了调查.共记录鸟类13目36科106种.其中,国家Ⅰ级重点保护鸟类1种,国家Ⅱ级重点保护鸟类10种.居留型方面,留鸟和冬候鸟最多,分别占鸟类物种总数的56.60％和35.85％.鸟类区系上,古北界种类最多,占41.51％;其次是东洋界鸟类,占32.08％.鸟类物种数1月份和3月份最多,多样性和均匀度指数均以12月份和3月份最高,以11月份和2月份最低.欧氏距离显示,修水段、龙虎山段和靖安段与其他河段的鸟类组成差异较大.宜黄段、耳口段和浮梁段的鸟类组成比较相近.研究结果表明,鸟类的相似度与各河段间隔的距离无关,而可能与当地的生境密切相关.鄱阳湖流域分布着一些濒危鸟类,然而人类活动如采砂、非法捕鱼等严重影响了这些鸟类的生存环境.因此建议降低人类活动强度,维持鄱阳湖流域鸟类多样性.     

Empirical assessment of potential interactions between walleye and smallmouth bass

The expansion of smallmouth bass Micropterus dolomieu throughout North America has created substantial changes in some food webs and created novel interactions with native predators in many systems through competition and predation, causing declines in native predator populations. In this study, we examined potential interactions between smallmouth bass (introduced) and walleye Sander vitreus (a native predator) in two Missouri River reservoirs and four natural lakes in South Dakota, USA, using historical standardized sampling data, which indexed four fitness‐related factors (relative abundance, size structure, condition, and growth) of both species. Of the 24 total relationships tested among all water bodies, three (13%) were determined to be significant (size structure in Pickerel Lake: P = 0.06; condition in Lake Kampeska: P = 0.06, and growth at Brant Lake: P = 0.02). Of these three, two relationships were negative as would be expected if negative interactions exist between these two species (size structure in Pickerel Lake: r = ?0.61; condition in Lake Kampeska: r = ?0.61); the remaining relationship was positive (growth at Brant Lake: r = 0.75). Further, no water body consistently demonstrated significant negative interactions in all relationships tested. The results of our study did not support the concept that introduced smallmouth bass interfere with walleye populations in South Dakota waters. Rather, it is more likely that other environmental factors influence the observed variability in walleye demographics and dynamics observed in this study. At this time, we believe that both fisheries will continue to co‐exist. However, continuous monitoring of both species is warranted as changing environmental conditions in the future could allow these interspecific relationships to shift toward the dominance of smallmouth bass over walleye.     

额尔古纳河流域秋季浮游植物群落结构特征

2008年8-9月对额尔古纳河流域5个重要水体呼伦湖、乌兰泡、二卡湿地、伊敏河和哈乌尔河进行浮游植物调查,结果显示：1）共鉴定浮游植物8门82属177种（含变种）,以绿藻和硅藻种类最多,绿藻有36属77种,占43.5%,硅藻21属54种,占30.5%;其次是蓝藻,13属26种,占14.7%;裸藻4属11种,占6.2%;其他藻类仅占5.1%;2）在呼伦湖共有64属121种,乌兰泡47属88种,二卡湿地62属116种,伊敏河41属59种,哈乌尔河32属54种;优势度分析显示：呼伦湖与乌兰泡优势种为蓝藻和绿藻,二卡湿地为硅藻与隐藻,伊敏河与哈乌尔河为硅藻;蓝藻个体密度在乌兰泡与呼伦湖最大,分别为5.17?106 ind./L和4.01?106 ind./L,而硅藻密度则在二卡湿地、伊敏河与哈乌尔河占优势,分别为1.40?106 ind./L、1.84?105 ind./L与4.89?105 ind./L;此外,聚类分析显示5个水体的浮游植物群落按结构特征可分为两大类;3）与历史记录相比,呼伦湖的优势种转变为细胞较小的坚实微囊藻(M. firma)与不定微囊藻(M. incerta),这种小型化的趋势表明呼伦湖水体富营养化程度加剧;4）综合多种指标对水质状况进行评估：呼伦湖、乌兰泡为中-富营养水体,二卡湿地为中营养水体,伊敏河与哈乌尔河属于贫-中营养水体。     

Ongoing Speciation in the Tibetan Plateau Gymnocypris Species Complex

Local adaptation towards divergent ecological conditions often results in genetic differentiation and adaptive phenotypic divergence. To illuminate the ecological distinctiveness of the schizothoracine fish, we studied a Gymnocypris species complex consisting of three morphs distributed across four bodies of water (the Yellow River, Lake Qinghai, the Ganzi River and Lake Keluke) in the Northeast Tibetan Plateau. We used a combination of mitochondrial (16S rRNA and Cyt b) and nuclear (RAG-2) genetic sequences to investigate the phylogeography of these morphs based on a sample of 277 specimens. Analysis of gill rakers allowed for mapping of phenotypic trajectories along the phylogeny. The phylogenetic and morphological analyses showed that the three sparsely rakered morphs were present at two extremes of the phylogenetic tree: the Yellow River morphs were located at the basal phylogenetic split, and the Lake Keluke and Ganzi River morphs at the peak, with the densely rakered Lake Qinghai morphs located between these two extremes. Age estimation further indicated that the sparsely rakered morphs constituted the oldest and youngest lineages, whereas the densely rakered morph was assigned to an intermediate-age lineage. These results are most compatible with the process of evolutionary convergence or reversal. Disruptive natural selection due to divergent habitats and dietary preferences is likely the driving force behind the formation of new morphs, and the similarities between their phenotypes may be attributable to the similarities between their forms of niche tracking associated with food acquisition. This study provides the first genetic evidence for the occurrence of convergence or reversal in the schizothoracine fish of the Tibetan Plateau at small temporal scales.     

Fish fauna, biogeography and conservation of freshwater fish in Poyang Lake Basin, China

A checklist of the fish of Poyang Lake Basin based on an extensive survey and literature review is presented. A total of 220 species and subspecies belonging to12 orders, 27 families and 100 genera, have been recorded. Of these, 131 species are endemic to China. Based on cluster analysis with presence-absence data, freshwater ecosystems in Jiangxi Province are divided into two regions, the Xunwushui River region and the region of Poyang Lake. The Xunwushui River flows into the Pearl River, whereas the region of Poyang Lake flows into the Yangtze River. The fish fauna and evolution of the fish fauna in Poyang Lake Basin owes much to geological events and belongs to the Oriental Region, South-east Asiatic sub-region and East China area. Anthropogenic activities including habitat alteration, overfishing, pollution and soil erosion have severely reduced the fish biodiversity in Poyang Lake Basin. River modifications (i.e. dam construction and sand excavation) and heavy metal pollution are the most significant threats to fish diversity and ecosystem functioning in the majority of the river systems in the province. To protect fish diversity and fisheries more effectively in Poyang Lake Basin, law enforcement should be strengthened, and the following measures could be introduced: restocking economically important fish species; establishing fish sanctuaries and freshwater protected areas, ordering a close season and developing sustainable aquaculture.     

鄱阳湖主要入湖段典型底栖动物体内微塑料累积特征

以鄱阳湖-饶河和鄱阳湖-赣江中支两个主要入湖段典型底栖动物(河蚬、圆顶珠蚌、中国圆田螺)为对象,通过组织消解、滤膜过滤分离和显微镜检筛分微塑料(粒径<5mm),分析底栖动物体内微塑料的累积特征。结果表明:三种底栖动物体内均有微塑料淀积且主要淀积于消化道组织中,不同物种淀积丰度表现为河蚬>中国圆田螺>圆顶珠蚌;淀积的微塑料类型包括颗粒类、碎片类、薄膜类和纤维类,其中以纤维类为主;微塑料颜色主要有透明、蓝、红、紫;粒径以<1 mm的丰度最高,且随粒径增大丰度呈递减的趋势;空间尺度上,饶河入湖段底栖动物体内微塑料丰度高于赣江中支入湖段。本研究表明,鄱阳湖微塑料污染已造成底栖动物体内微塑料的累积,湖水产品的食用需要谨慎,但与国内外其他研究相比,本次研究区域的底栖动物处于中等微塑料污染。     

The parasite fauna and structures of parasite communities of Oreoleuciscus humilis Warpachowski, 1889 from Ust-Nur Lake (Selenga River basin) and Tuin-Gol River (Goby Lakes Valley)

The parasite fauna of Oreoleuciscus humilis from the Ust-Nur Lake (Selenga River basin), Tuin-Gol River (Goby Lakes Valley) are given for the first time. We found 9 species of Oreoleuciscus humilis parasites, 5 species is revealed for the first time for this host. Infracommunities of parasites of Oreoleuciscus humilis in the Tuin-Gol River are balanced and mature, in the Ust-Nur Lake are not balaced and not mature.     

应用原生动物群落评价枯水期白洋淀的水质现状

应用PFU微型生物群落监测方法,对长期处于低水位状态下的白洋淀水质进行了综合评价。结果表明,白洋淀水域受府河污水的影响,淀内的内源性污染,对原生动物群落造成了极大的影响。与20世纪90年代的资料相比,淀内中心区4个采样点原生动物的群集种类数(1d)急剧下降,而丰度上升了1．28倍,表明内源性污染对白洋淀水质的影响加剧。     

安徽沿淮湖泊湿地水鸟资源调查

2008年6月至2009年5月,采用路线调查法和定点观察法对安徽沿淮的东西湖、瓦埠湖、龙子湖、沱湖和女山湖5个湖泊湿地的水鸟资源进行了调查,共记录湿地水鸟61种,隶属于7目13科.按居留型可分为冬候鸟32种(占52.46%),夏候鸟14种(占22.95%),留鸟2种(占3.28%),旅鸟13种(占21.31%);按生态...     

长江流域兽类物种多样性的分布格局

共记录了长江流域内兽类280种,隶属于11目36科135属,特有种和受威胁物种分别有14种和154种。根据兽类分布特点,依据山系和水系将长江流域分为19个区域,除了江源区外,物种丰富度、G-F多样性指数和特有种比例,从上游到下游区域总体趋势是随海拔降低逐渐降低,形成以四川盆地和沅江为分界线的3个数量级;利用Jaccard物种相似性系数对长江流域内19个区域进行聚类分析,发现整个流域分成4部分:江源区;横断山区、川西高原、云南高原、四川盆地和秦巴山区;贵州高原、江南丘陵、鄱阳湖平原和长江三角洲;淮阳山地、两湖平原和长江下游平原,基本反映了流域内自然地理环境及我国大陆地势三级台阶变化的特点。     

Evolutionary history of the endemic Lake Tanganyika cichlid fish Tylochromis polylepis: a recent intruder to a mature adaptive radiation

With an age of 9–12 million years (Myr) Lake Tanganyika holds the oldest and most complex species flock of cichlid fishes. It is believed to be of polyphyletic origin and rooted in nine ancient African lineages, six of which underwent diversification, while three remained monotypic. Here, the evolutionary history, route and timing of colonization were analyzed, as well as intraspecific genetic diversity of Tylochromis polylepis , the single albeit endemic representative of the tribe Tylochromini in Lake Tanganyika. The role of Tylochromis in the radiation was uncertain and the species was suggested to be either an ancient colonizer or a recent addition to the fauna. With 2.8–4.2% sequence divergence to four congeners living in Lakes Bangweulu and Mweru (Upper Congo River) as well as from Luozi River and Lake Etsotso (Lower Congo River), the species appears to be a recent colonizer, which is likely to have diverged from its riverine allies less than 510 000 years ago. The ability to enter an adaptive radiation at a highly mature stage with its densely packed species community and fine-tuned niche segregation seems remarkable. So far it was assumed that all Tanganyikan endemics evolved within the lake ecosystem by intralacustrine speciation, and that complex competitive interactions among endemics tighten the system against intruders. The intruding species can be classified as a generalist living over muddy bottom in the lake and in river estuaries. Microgeographic substructuring is suggested, possibly because of geographic segregation of breeding sites. Concerning the route of colonization, a downstream movement via one of the inflowing rivers situated in the south of Lake Tanganyika is suggested.     

Stable isotope analyses in otoliths of silver carp: a pilot study in identification of natal sources and stock differences

Silver carp, Hypophthalmichthys molitrix, is one of the four major fishes in China for fishing and aquaculture. The Yangtze River and associated waterbodies are important home to silver carp. In this study, we collected 135 otoliths of juvenile silver carp from the two rivers and the Poyang Lake, and analyzed for stable oxygen and carbon isotope ratios (δ¹⁸O and δ¹³C). The isotopic data and correlation of δ¹⁸O versus δ¹³C showed a clear separation and significant differences (p?<?0.001 for both δ¹³C and δ¹⁸O) between otoliths from the Ganjiang River and the Yangtze River at δ¹⁸O values around ?10‰. The Poyang Lake samples were overlapped with those of the Ganjiang River, but distinctly different from the Yangtze River samples. These isotopic signatures agree well with the previous genetic investigation results that there are marked distinctions between one population in the Ganjiang River and the other in the Yangtze River, and the Poyang Lake population belongs to the Ganjiang River rather than to the Yangtze River. Thus we concluded that stable isotope analyses of otoliths can be effectively used to study natal sources and stock differences of silver carp.     

New data about distribution of lower Amur grayling <Emphasis Type="Italic">Thymallus tugarinae</Emphasis> and Baikal-Lena grayling <Emphasis Type="Italic">Thymallus</Emphasis> sp. (Thymallidae) in the basins of the upper Amur River and Zeya River

New findings of lower Amur grayling (Lower Amur grayling) Thymallus tugarinae and Baikal-Lena grayling Th. sp. (Th. baicalolenensis) in the basins of the upper Amur River and Zeya River are reported for 2010?2014. Lower Amur grayling has been registered in the tributaries of Argun River and in the middle stream of Ingoda River. Baikal-Lena grayling has been found for the first time in the headstream of Ingoda River. New data about the distribution of this species in the basin of upper stream of Zeya River are reported; particularly, Baikal-Lena grayling has been found in Okonon Lake; this is the first finding of a representative of Thymallidae family in the alpine lakes of the watershed area of Amur River. In the basins of upper Amur River and Zeya River, the summer ranges of upper Amur grayling Th. grubii grubii and lower Amur grayling overlap to some extent; on the other hand, the ranges of Baikal-Lena grayling and lower Amur grayling are disjoint. During the summer period, upper Amur grayling and Baikal-Lena grayling together inhabit the basin of upper stream of Zeya River, but only Baikal-Lena grayling has been found in the headstream of Zeya River. In the basin of upper Amur River (the headstream of Ingoda River), the joint range of these species is still unknown; the sympatric zone is located in Dzhermoltai River (the basin of Onon River).     

太浦河大型底栖动物群落组成及时空分布特征

太浦河连接东太湖和黄浦江,是东太湖向下游行洪的主河道,也是黄浦江上游重要的引水水源。分别于2017年10月、12月和2018年3月、6月在太浦河沿程设置的5个站点开展了大型底栖动物季节频次的取样调研,分析了太浦河大型底栖动物群落的结构特征及其主要影响因子。调查期间共采集到大型底栖动物25种,隶属于3门6纲14科,其中以河蚬（Corbicula fluminea）为代表的双壳类和以铜锈环棱螺（Bellamya aeruginosa）为代表的腹足类处优势地位。太浦河大型底栖动物群落的密度、生物量及多样性特征在不同站点间均存在显著差异（P<0.05）;而在不同季节间均不存在显著差异（P>0.05）。聚类排序分析表明,太浦河大型底栖动物群落在空间上的差异较季节间的变化更为明显。太浦河大型底栖动物群落的物种组成特征与太浦河、东太湖的水文连通格局密切相关;而沿程不同程度人为干扰下的水体营养水平以及底质类型与生境异质性等生境条件对太浦河大型底栖动物群落的分布特征具有重要影响,其综合作用机理有待进一步研究。     

Shoreline displacement of Lake Ladoga — new data from Kilpolansaari

Dating of sediments sampled from small lakes in the Kilpolansaari region, in the NW part of Lake Ladoga, indicate that the River Neva, which is the present outlet of Lake Ladoga, originated at 3,100 radiocarbon years BP This is in agreement with some earlier estimations but no consensus concerning the age of the River Neva has previously been reached. New diatom data provide information concerning salinity and nutrient conditions in northern Lake Ladoga prior to the formation of the River Neva, when the Litorina Sea occupied the Baltic basin and approached the level of the ancient Lake Ladoga. Some slightly brackish water diatom species may indicate occasional saline water incursions into the Ladoga basin but, on the other hand, slightly brackish water species also occur in the present Lake Ladoga.     

Distribution pattern, threats and conservation of fish biodiversity in the East Tiaoxi, China

East Tiaoxi River is one of the largest inflowing rivers into Taihu Lake, and the fish fauna in the river is poorly understood. In the present study, an extensive survey of fish was conducted in October and November 2009, May and September 2010 and May 2011 covering a total of 55 sites along the whole river. A total of 84 freshwater fish species belonging to 8 orders, 18 families and 52 genera have been recorded. Among these are 35 species endemic to China, and 3 newly recorded exotic species. The fish composition varies greatly from headwaters to downstream. Based on cluster analysis with presence-absence data, the East Tiaoxi River is divided into four regions, specifically, the upper reach, middle-up reach, middle reach and lower reach. It is observed that species richness and the proportion of omnivorous species increased from upstream to downstream while the proportion of invertivorous species decreased consequently. Habitat alteration, overfishing, pollution and inland navigation adversely affect the fish diversity and ecosystem functioning in the East Tiaoxi River. To protect fish diversity more effectively in the area, the conservation of fish biodiversity in the North Tiaoxi River and Middle Tiaoxi River should be considered as a priority. Meanwhile, shallow zones or backwater areas should be created in the middle-lower reaches. Furthermore, river restoration, in terms of habitat creation, should be considered to protect the structure and diversity of fish communities, halt the progressive deterioration of freshwater ecosystems and sustain a valuable ecological resource for humans.     

An annotated checklist of the fish fauna of the river systems draining the Kahuzi-Biega National Park (Upper Congo: Eastern DR Congo)

The Kahuzi-Biega National Park (KBNP), situated mainly in the Eastern Highlands Ecoregion of the Upper Congo basin, is drained by the Lowa and Ulindi rivers, and some western affluents of Lake Kivu. In this study, the first list of the fish diversity of these systems is provided based on museum collections and complemented, for the Lowa River system and the western Lake Kivu affluents, with recently collected specimens (2013–2017). A total of 118 species are reported from the Lowa basin, 22 from the Ulindi basin and seven from these Lake Kivu affluents. Within the Lowa and Ulindi, respectively, five and one species, all cichlids, have been introduced. Currently, 51 species are reported from within the park, only two of which have been reported from the highlands, i.e., Amphilius kivuensis from the Luha, the source of the Luka River, and Clarias liocephalus from the headwaters of the Lake Kivu’ affluents. With a total of 30 species, Cyprinidae is by far the largest family, representing 25% of the total species diversity of the Lowa basin. It is followed by Mormyridae with 13 species (11%), Alestidae and Mochokidae with 10 species each (8%), Clariidae and Amphiliidae with eight species (7%), and Distichodontidae with six species (5%). Seven new species for science were discovered and 11 species were found to be endemic to the Lowa system. Although further exploration is needed, this underscores the importance of the KBNP in protecting the fish fauna of the Lowa basin but also highlights the park's limited coverage of the fish fauna of the Lowa basin.     

Some fungi of the cache la Poudre River,Colorado

Summary Samples of water, bottom sediment, bank soil, and upland soil from nine stations on the Cache la Poudre River, Colorado, from Poudre Lake (elevation 10,752 feet) in Rocky Mountain National Park to a point near its confluence with the South Platte River near Greeley, Colorado, on the Great Plains were examined for fungal populations. A total of 128 species of fungi were recovered on four types of bait, agar, and liquid media. While human, animal, and plant pathogenic fungi were present, species found were of wide-spread occurrence and no serious involvement was noted. If streams such as this continue to receive organic enrichment, increasing loads of potentially pathogenic fungi possibly may be found.     

中华鳖非特异性免疫功能的群体差异研究

从补体总量、红细胞C3 b受体花环率、红细胞天然免疫肿瘤细胞花环率、T淋巴细胞活性E花环率及白细胞吞噬活性五方面 ,探讨了黄河鳖、淮河鳖、洞庭湖鳖、鄱阳湖鳖及太湖鳖在非特异性免疫功能上的差异。主要结果 :(1)在补体总量及红细胞天然免疫肿瘤细胞花环率上 ,五群体之间差异不显著 (F <0 .0 5 ) ;(2 )在红细胞C3 b受体花环率上 ,黄河鳖显著地高于鄱阳湖鳖与太湖鳖 (P <0 .0 5 ) ,而其余群体间则差异不显著 (F <0 .0 5 ) ,花环率大小顺序为 :黄河鳖 >淮河鳖 >洞庭湖鳖 >鄱阳湖鳖 >太湖鳖 ;(3)在T淋巴细胞活性E花环率上 ,黄河鳖显著高于鄱阳湖鳖 (P <0 .0 5 ) ,太湖鳖极显著地低于其他四个群体 (F >0 .0 1) ,其余群体间则差异不显著 (P >0 .0 5 ) ,花环率大小顺序为 :黄河鳖 >淮河鳖 >洞庭湖鳖 >鄱阳湖鳖 >太湖鳖 ;(4 )在白细胞吞噬活性上 ,除淮河鳖与鄱阳湖鳖差异不显著外 (P >0 .0 5 ) ,其余群体间则差异极显著 (F >0 .0 1) ,活性大小顺序为 :黄河鳖 >洞庭湖鳖 >淮河鳖 >鄱阳湖鳖 >太湖鳖。综上所述 ,在非特异性免疫功能上 ,黄河鳖最强 ,太湖鳖较弱。