贵州省红枫湖现生介形类新纪录

本文首次记述了采自我国贵州省红枫湖的现生介形类5属7种,分别为:近锐豆形玻璃介Fabae formiscandona subacuta(Yang,1982)、比利时舍氏玻璃介(相似种)Schellencandona cf.belgica(Klie,1937)、亮球星介Cy-clocyprisserena(Kock,1838)、克氏丽星介Cypria kraepelini(G.W.Müller,1903)、条纹薄壳介(相似种)Dolerocypris cf.fasciata(O.F.Müller,1776)、布氏土星介Ilyocypris bradyi Sars,1890、粗糙土星介I.sale-brosa Stepanaitys,1960。这些属种在红枫湖和贵州省均系首次报道,其中S.cf.belgica在我国是首次发现,文内对F.subacuta活体特征的描述在我国尚属首次。     

华东地区元荡湖现生介形类新记录

本文首次记述了采自我国东部元荡湖的现生介形类7属9种,分别为:近球形金星介Cypris subglobosa Sowerby,1840、膨大丽神介Cypretta turgida(Sars,1896)、克氏丽星介Cypria kraepelini(G.W.Müller,1903)、无偶斗星介Cypridopsis vidua(O.F.Müller,1776)、塔尔薄丽星介Dolerocypria taalensis Tressler,1937、豆形豆形玻璃介Fabaeformiscandona fabaeformis(Fischer,1851)、弯叶豆形玻璃介F.myllaina Smith et Kamiya,2007、豆形玻璃介(未定种)Fabaeformiscandonasp.和粗糙土星介Ilyocypris salebrosa Stepanaitys,1960。这些属种在太湖流域的淀泖湖群系首次报道,其中F.myllaina和I.salebrosa均首次报道于我国东部湖区。本研究丰富了我国介形类记录,可为介形类地理区系研究提供基础资料。     

太湖介形虫分布与水环境因子间关系的典范对应分析

2004年9月至2005年8月间对太湖介形虫分布状况进行了季节性的调查,共获得介形虫15种,其中克氏瘤丽星介Physocypria kraepelini,豆形豆形玻璃介(比较种)Fabaeformiscandona cf.fabaeformis和塔尔薄丽星介Dolerocypria taalensis的出现频度分别达71.05%、44.74%和42.11%,为太湖水体中的常见种。相似性分析(UPGMA)结果表明太湖介形虫可分为四个不同的类型,即终年出现物种、仅秋季出现物种、夏秋季出现物种和仅春季不出现的物种。应用典范对应分析(Canonical Correspondence Analysis,CCA)对太湖38个样点的15种介形虫与9个环境因子关系研究的结果是介形虫与环境因子间的相关性高达100%,提示太湖水体环境因子变化影响了介形虫的分布和季节性变化;水体的9个环境因子中的pH值、植被密度、总磷和总氮对介形虫的分布影响最大;而化学需氧量和溶氧量对其也有一定的影响。从物种分布状况看,稳定湖花介Limnocythere stationis对水体中环境因子的敏感性明显高于其它物种,其高分布频度对高总磷和高叶绿素具指示作用;太湖中的三种常见种介形虫(克氏瘤丽星介、豆形豆形玻璃介(比较种)和塔尔薄丽星介)的分布主要受总磷和化学需氧量的影响,其高分布频度是水体高化学需氧量的良好指标种;在高总氮和高化学需氧量的春季水体中无角尾狭星介Stenocyprisderupta,近球形金星介Cyprissubglobosa,上野湖湾介Strandesiauenoi,绿色湖湾介S.viridis,条纹湖湾介S.vittata,环星介(未定种)Zonocypris sp.和史氏达尔文介Darwinula stevensoni的出现,暗示这些物种的高分布频度可以指示水体中的低总氮和低化学需氧量。     

云南滇池淡水介形类新记录

本文记述了采自我国云南省滇池的淡水介形类5种现生种,即泽氏玻星介Candonocypris novaezelandiae(Baird)、青春金星介Cypris puberaO.F.Mller、黑纹斗星介Cypridopsis nigrovittataOkubo、非调和异星介Heterocypris incongruens(Ramdohr)和克氏瘤丽星介Physocypria kraepelini G.W.Mlle。它们在滇池和云南省系首次报道,其中C.novaezelandiae在我国是首次发现。同时描述了两个种的软体组织,增添了我国高原断陷湖泊现生介形类动物群名录。     

江苏盐城大丰滨海岩芯中的全新世介形类及古环境变迁

本文对江苏省盐城市大丰野鹿荡DF20岩芯(北纬33°3.14′,东经120°48.05′,岩芯长21 m)中的全新世介形类进行了研究。从该岩芯的61个沉积物样品中获取介形类壳瓣逾1 700枚,鉴定出35属45种,这些属种被划归三个生态分布型,按个体数量由多到少顺序分别为滨岸低盐水型(Sinocytheridea impressa, Neomonoceratina dongtaiensis,Leptocythere ventriclivosa等)、内陆架沿岸水型(Pistocythereis bradyformis,Bicornucythere bisanensis等)以及中陆架外海水型(Munseyella pupilla, Cytheropteron cf. sawanense等)。介形类个体密度及生态分布型组合变化,显示近7 000年来野鹿荡地区经历了三个沉积时期:I期(孔深19.6～7.5 m),处于潮下带,砂质底,海藻/海草繁茂,底栖生物生产力水平较高; Ⅱ期(7.5～2 m),由潮下带急速过渡为潮间带,泥质底,底栖生物生产力水平低; Ⅲ期(2～0.85 m),处于潮下带,砂质...     

甘南高寒草甸土壤纤毛虫对磷酸氢二铵添加的响应

为研究磷酸氢二铵(DAP)添加对土壤纤毛虫群落结构的影响,于2012年4月在甘南高寒草甸选取典型样地,在0～120 g·m^-2浓度区间内设置5个添加水平,采用“非淹没培养皿法”、活体观察法和“3级10倍环式稀释法”测定土壤纤毛虫物种数和密度,同时测定了土壤相关环境因子(含水量、pH值、总氮、总磷、有机碳).共获得土壤纤毛虫129种,隶属9纲17目31科46属.对照组的土壤纤毛虫物种数和物种多样性指数均大于施肥处理,且随着施肥量的增大,土壤纤毛虫物种数减少,物种多样性减小,但其密度随施肥量的增大而增加.对照土壤纤毛虫优势类群为刺钩目,随着施肥量的增大,土壤纤毛虫优势类群更新为肾形目.土壤纤毛虫群落结构和环境因子的冗余分析表明,总磷、土壤温度和含水量是影响甘南高寒草甸土壤纤毛虫群落分布的关键环境因子.     

广东南雄盆地南雄群的介形类动物群

南雄群及其介形类化石在我国晚白垩世非海相地层划分对比中占重要地位,主田和杨梅坑剖面主田组和浈水组中有270个样品含介形类化石,计有23属(2亚属)99种(12新种)。南雄群介形类动物群是以Talicypridea,Cypridea,Nanxiongium,Candoniella等4属为主,称Talicypridea Cypridea Nanxiongium动物群(简称Tali cypridea动物群)。该动物群在我国和蒙古的非海相地层中广泛分布,时代属晚白垩世中—晚期。     

海洋浮游介形类的多样性和生态学研究进展

海洋浮游介形类(ostracods)是一类分布较广的小型甲壳动物, 大多数是典型的有机碎屑摄食者, 本身又是中深层鱼类的饵料, 在海洋碳循环中起重要作用。目前海洋浮游介形类研究主要集中在海洋表层, 大约还有200—400 种的海洋浮游介形类未被发现, 尤其是栖息于深海的种类。今后介形类分类学研究的重要趋势之一是深海种类的发现。我国介形类研究起步晚, 积累少, 应加强我国不同海域深海介形类及其与环境关系的深入研究。文章综述了海洋浮游介形类的多样性和生态学等方面的研究进展, 重点概述了海腺萤科分类的发展, 比较分析了不同海域介形类的物种多样性和分布特征, 总结了浮游介形类的生态作用及其影响因素, 概括了我国海洋浮游介形类的研究现状, 以期为海洋生物多样性、海洋生物地球化学循环以及深海生态学等方面的研究提供基础依据。     

太子河河岸带土壤理化性质特征及其与环境因子的关系

根据太子河河岸带69个样点的土壤分层调查, 研究了太子河河岸带土壤特征、空间格局及与环境因子的关系。研究结果表明:垂直剖面自上而下土壤含水率、土壤孔隙率、总磷、有机质和总氮含量显著减少, 容重、pH和有效磷在层间差异不显著。根据土壤理化性质, 将样点分为2类, 一类主要分布在太子河上游及某些支流上游, 该类土壤呈弱酸性, 有机质和总氮含量高, 另一类主要分布在太子河中下游, 该类土壤呈弱碱性, 有机质和总氮含量较低。利用冗余分析(RDA)识别影响土壤性质的环境因子, 结果表明海拔、年降水、年均温和距离河口的距离是影响土壤空间差异的主导因子。     

氮磷汇入驱动下的河流轮虫群落演替

【目的】解析污染条件下河流生物区系的演替过程及机制,可以为生物多样性减少提供诊断,为生物多样性保护和水生生态系统的生态安全提供科学支撑。【方法】以对污染具有指示作用的轮虫类群为研究对象,选择覆盖京津冀地区的、受到人类活动干扰的北三河水系为研究区域,分别对该区域富营养化相关水质参数和轮虫群落组成进行分析,在解析污染物排放导致的河流水体水质差异和轮虫群落组成差异的基础上,阐明导致轮虫群落演替的关键污染因子。【结果】水体水质指标的分析结果表明,西部河流与东部诸河具有明显不同的环境条件,其氮、磷指标(包括总氮、溶解性总氮、总磷、溶解性总磷及活性磷)浓度显著增加。轮虫群落的分析结果表明,与东部诸河相比,西部河流的物种数目、生物个体数、物种丰度及香农威纳指数均显著降低,且群落组成显著差异。群落-环境相关分析显示,总氮、溶解性总氮、总磷、溶解性总磷、活性磷以及氨氮是导致群落显著差异的关键环境因子。【结论】北三河水系西部河流的氮、磷含量显著高于东北部河流;在环境条件改变的前提下,北三河水系西部河流比东部河流物种丰度、生物量均显著减少,同时群落组成也显著改变,高耐污型物种出现。氮、磷元素的输入是导致轮虫群落演替的关键环境因子。     

Land use and ostracod community structure

Ostracods are important members of the benthos and littoral communities of lake ecosystems. Ostracods respond to hydrochemistry (water chemistry) which is influenced by climatic factors such as water balance, temperature, and chemicals in rainfall runoff from the land. Thus, at local scales, environmental preferences of ostracods and characteristics of lakes are used to infer changes in climate, hydrology, and erosion of lake catchments. This study addresses potential drivers of ostracod community structure and biodiversity at multiple spatial scales using NMS, CART^?, and multiple regression models. We identified 23 ostracod species from 12 lake sites. Lake area, maximum depth, spring conductivity, chlorophyll a, pH, dissolved oxygen, sedimentary carbonate, and organic matter all influence ostracod community structure based on our NMS. Based on regression analysis, lake depth, chlorophyll a, and total dissolved solids best explained ostracod richness and abundance. Land uses are also important community structuring elements that varied with scale; locally and regionally agriculture, wetlands, and grasslands were important. Nationally, using regression tree analysis of lakes sites in the North American Non-marine ostracod database (NANODe), row-crop agriculture was the most important predictor of biodiversity. Low agriculture corresponded to low species richness but greater landscape heterogeneity produced sites of high ostracod richness.     

Mapping the observed and modelled intracontinental distribution of non-marine ostracods from South America

Ecological niche modelling (ENM) has been used to quantify the potential occurrence of species, by identifying the main environmental factors that determine the presence of species across geographical space. We provide a large-scale survey of the distribution of ostracod species in South America, by using the domains of 25 river basins. From 221 known ostracod species, we estimate the potential distribution of 61 species, using ENM. Ten clusters of potential distribution patterns were found. Clusters 8 and 9 grouped most of the species, which presented high similarity of niche between them. Heterocypris paningi Brehm, 1934 (group 1) obtained higher niche variability. The minimum temperatures of the coldest month and the mean elevation of the river basin were most important to predict the potential distribution of ostracods of most groups. South America has a complex pattern of elevation, which affects species distributions indirectly through changes in local factors. For instance, the Andes mountains might impose a barrier for ostracod distribution in the southern part of South America because of the low temperatures and precipitation. The ENM indicated that some regions and/or basins of South America might be susceptible to the entry of several ostracod species, presently absent, including non-native species.

     

Freshwater ostracod assemblages and their relationship to environmental variables in waters from northeast Germany

An ecological calibration dataset for freshwater ostracods from 33 localities throughout West-Pomerania (Mecklenburg-Vorpommern, Germany) was evaluated using multivariate statistical methods. A total of 47 freshwater ostracod species were identified. Nine species were rediscovered after 100 years since the last published record and Candonopsis scourfieldi and Pseudocandona sucki was recorded for the first time in the study area. Special emphasis is put on the phenology of each species to gain information on the water characteristics at the time of their last moult. Canonical correspondence analysis (CCA) revealed that the ecological variables such as water temperature, Ca, Mg, and lake area were statistically most significant (p < 0.005; n = 72) in explaining variation in the distribution of ostracod assemblages. In addition, a transfer function was developed for paleolimnological approaches, based on a weighted-averaging (WA) model to calculate water temperature from the relative abundances of 22 selected ostracod species. This model was successfully applied to infer lake water temperature from subfossil ostracod assemblages collected from lacustrine deposits in northeast Germany (Lake Krakower See). Electronic supplementary material Electronic supplementary material is available for this article at and accessible for authorised users.     

Distribution and faunal associations of benthic invertebrates at Lake Turkana,Kenya

The benthic environment and fauna of Lake Turkana were studied during 1978–1979 to determine distribution patterns and associations of benthic invertebrates. Lake Turkana is a large, closed-basin, alkaline lake, located in northern Kenya.Detailed environmental information is currently only available for substrate variations throughout Lake Turkana. Water chemistry and other data are currently inadequate to evaluate their effects on the distribution of Lake Turkana benthic invertebrates. Three weak faunal-substrate associations were discovered at Turkana. A littoral, soft bottom association (large standing crop) is dominated by the corixid Micronecta sp. and the ostracod Hemicypris kliei. A littoral, rocky bottom association, also with a large standing crop, is dominated by various gastropods and insects. A profundal, muddy bottom association, with a very small standing crop, is dominated by the ostracods Hemicypris intermedia and Sclerocypris cf. clavularis and several gastropod and chironomid species.     

不同类型景观水体浮游动物群落差异及其影响因素

探明不同类型景观水体中环境敏感型浮游动物群落特征差异及影响因素对景观水体生物多样性维持和水生生态系统保护十分重要。于2014年5月在上海选取具代表性的8个景观水体共设置35个采样点进行浮游动物采样调查,并同步测定水体环境指标。本次调查采集并鉴定浮游动物40种,其中轮虫29种,枝角类7种,桡足类4种。基于浮游动物群落组成进行聚类分析,所有采样点聚为四种景观类型:天然湖泊(淀山湖)、人工湖泊(滴水湖)、AAAA级公园水体(共青森林公园和古猗园)和普通综合性公园水体(世纪公园、和平公园、长风公园和车镜公园)。两种公园水体浮游动物种类较为丰富,多样性较高,各自约有40%的种为生境特有种,而淀山湖特有种仅1种(为猛水蚤),滴水湖3种均为蛭态类。物种相似性方面,大型天然淀山湖与人工滴水湖相似性最高(37.5%),普通公园水体次之(33.3%),与AAAA公园水体相似度最低(20%)。后两者间的相似性较高(27.8%),且两者与滴水湖的相似度均较低(18.5%和12.0%)。四类水体仅有3个共有种/类群:角突臂尾轮虫(Brachionus angularis)、螺形龟甲轮虫(Keratella cochlearis)和桡足类无节幼体。AAAA公园水体中甲壳纲动物的相对丰度(88.8%)远高于其他水体,其优势种由3种大型浮游动物(甲壳纲)组成,普通公园水体优势种仅由4种小型浮游动物(轮虫)组成,淀山湖和滴水湖的群落结构简单,优势种单一。冗余分析(RDA)显示,水温、透明度、pH、化学需氧量、氨氮和总磷是影响景观水体浮游动物群落差异的显著环境因子。     

Ostracod Assemblages in Relation to Littoral Plant Communities of a Shallow Lake (Lake Świdwie,Poland)

The aims of this study included: specifying values of ecological parameters and Ostracoda species characteristic for different types of plant habitats occurring in lake systems, determining the impact of mud presence on the taxonomic structure and density of the ostracods, tracing seasonal changes in the structures of Ostracoda assemblages identifying the species typical of particular seasons. Various types of rushes and underwater meadows were taken into consideration as lake microhabitats. The research was conducted in the shallow Lake Œwidwie (NW Poland). Multivariate (constrained) ordination methods were used to analyse the relationships between species composition and environmental variables. In the lake and its margins 31 species of the Ostracoda were identified. The development of water vegetation during the vegetation season was conducive to growth in ostracod density. The accessibility of mud in plant habitats had a favourable effect on the general density of ostracods. Species which preferred a high mud content in their habitats included: Cypria ophtalmica, C. exsculpta and Physocypria kraepelini. Species typically encountered in underwater meadow habitats were: Cyclocypris ovum and Cypridopsis vidua. Underwater meadows of charophyte were characterized by the highest ostracod density in the whole lake system, with the average of 7860 ind. m^–2 and the maximum of 17 470 ind. m^–2. Species typically encountered in rush habitats included Notodromas monacha, Dolerocypris fasciata and Metacypris cordata. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Ostracod distribution in Ulungur Lake (Xinjiang,China) and a reassessed Holocene record

Ostracod shells in surface sediments from Ulungur Lake (Xinjiang, China) belong mainly to Limnocythere inopinata as the dominant species, and Candona neglecta and Darwinula stevensoni as accompanying, less abundant taxa. Shells of an additional nine species were recorded only sporadically. The three most abundant ostracods have wide tolerance ranges in terms of salinity, substrate and water depth. The similarly recorded bivalve Pisidium subtruncatum, and the gastropods Gyraulus chinensis and Radix auricularia belong to the most tolerant representatives of the genera. The bivalve and gastropods, in addition to the ostracod assemblage, reflect the fact that Ulungur Lake has experienced strong lake level and salinity variations due to water withdrawal in the catchment and the counteracting diversion of river waters to the lake in recent decades. The substrate in Ulungur Lake is typically fine-grained, apart from the delta region of the Ulungur River channel, which is marked by relatively coarse-grained detrital sediments barren of ostracod shells. This channel was created 40 years ago to divert water to Ulungur Lake and support its local fisheries and recreational facilities. A reassessed Holocene ostracod record from the lake shows that a significantly higher salinity and lower lake level existed in the early Holocene before 6.0 ka in response to the regional climate. In contrast, a higher lake level and lowest salinity is inferred for the late Holocene period between ca. 3.6 and 1.3 ka before present. Afterwards, the lake level declined and salinity increased in response to regional moisture reduction, although conditions similar to the early Holocene lake status were not re-established. Our surface-sediment-derived data provide a baseline for analysis of future environmental variations due to global climate change and regional water management.     

Ostracods and the Holocene palaeolimnology of Lake Qarun, with special reference to past human–environment interactions in the Faiyum (Egypt)

We present an ostracod record covering the past two millennia from an 8.25-m core taken from Lake Qarun, in the Faiyum Depression of Egypt. The occurrence of ostracod species in the lake is controlled primarily by variations in solute composition, which are in turn related to shifts in catchment land use. At times when the Faiyum Depression supported thriving agriculture, lake water contained Na⁺–Cl^? brine, and Cyprideis torosa dominated the ostracod assemblage. When the Faiyum Depression experienced periods of environmental and economic decline, lake water contained Na⁺–HCO₃ ^? brine, and Limnocythere inopinata dominated. The relative abundance of other ostracod species provides additional information about past conditions in Lake Qarun including salinity and lake level changes. Overall, the ostracod assemblages provide evidence for human influences in the Faiyum, which extend back before instrumental or detailed observational records began.     

松辽盆地D80井嫩一段介形类化石壳体特征及生物地层

松辽盆地嫩江组一段富含介形类化石,是系统研究Santonian期陆相介形类的理想层位。论文对中央坳陷区D80井嫩一段的介形类化石进行了系统的分类、生物地层和壳体特征分析。鉴定出介形类化石11属30种,划分出6个介形类化石带,并与前人的研究结果进行了对比;描述了该段介形类化石的壳体结构,共识别出4种壳饰类型,8种壳形结构,基于介形类壳体特征和其他证据,初步探讨了该时期湖盆湖平面的变化特征,显示出嫩一段时期松辽湖盆湖平面经历了由深逐渐变浅的过程。     

Distribution of Recent ostracod species in the Lake Qinghai area in northwestern China and its ecological significance

In order to interpret the climate-change data using the ecological characteristics of the ostracods from the drill cores in Lake Qinghai, the distribution of Recent ostracods was studied in Lake Qinghai area. A total of 34 species belonging to the Ostracoda class of Crustacea were collected from different bodies of water in the Lake Qinghai area, and the ecological information for Recent ostracod species was studied. Among these 34 species, Cypris pubera, Eucypris dulcifons, Ilyocypris sp. 1, Ilyocypris sp. 2, Fabaeformiscandona caudata, Fabaeformiscandona hyalina, Herpetocypris reptans, Prionocypris gansenensis, Potamocypris villosa, Potamocypris smaragdina, Paralimnocythere compressa and Subulacypris sp. were first reported by us in the Lake Qinghai area. Some of the species identified exhibited cosmopolitan distributions, at least in the Holarctic region, but P. gansenensis and Ilyocypris echinata appeared to be restricted to the cold regions in northwestern China.The ecological significance of the primary ostracod species in the Lake Qinghai area was described according to the observations made during our time in the field and according to data from a number of reports. Our results indicate that the species diversity and abundance of ostracods may be related to water salinity in the Lake Qinghai area. The ecological information for ostracods can be used to distinguish different water environments and types based on the characteristics of one species or of an assemblage of several species.