A new structurally preserved fern rhizome of Osmundaceae (Filicales) Ashicaulis wangii sp. nov. from the Jurassic of western Liaoning and its significances for palaeobiogeography and evolution

Permineralized osmundaceous rhizome with anatomical and phylogenetic information plays a significant role in understanding the origin,evolution,and diversity variation of the fern family Osmundaceae in geological history.The northern Hebei and western Liaoning region is one of the most important fossil localities for the Jurassic osmundaceous rhizome fossils in the Northern Hemisphere;however,the diversity character of osmundaceous rhizome fossil remains poorly known.A new structurally preserved fern rhizome species,Ashicaulis wangii sp.nov.,is described from the Middle Jurassic Tiaojishan Formation in Beipiao City,Liaoning Province,northeastern China.The rhizome is composed of heterogeneous pith,an ectophloic–dictyoxylic siphonostele,a two–layered cortex,and a mantle of adventitious roots and petiole bases.The xylem cylinder,with complete leaf gaps,consists of 15–17 xylem strands.The petiole base is characterized by a heterogeneous sclerotic ring and numerous sclerenchyma masses in the petiolar cortex.Among five known Ashicaulis species with heterogeneous sclerotic ring,four of them are documented from China.Therefore,osmundaceous rhizome fossils from China show endemic anatomical characteristics and significances for palaeobiogeography.Comparisons of anatomical features suggest that A.wangii sp.nov.bears close similarities to Osmunda pluma Miller from the Paleocene of Dakota,USA.Fossil species of A.wangii provides new evidence for further understanding the species diversity of osmundaceous rhizome fossil in China and in the Northern Hemisphere,and contributes to exploring the macroevolution process of the Mesozoic osmundaceous plants.     

Notiz zur Phagotrophie einerSpumella-Art (Chrysophyceae) im Walchensee

Monophagy ofSpumella sp. Cienkowsky (1870) (Chrysophyceae) from the mesotrophic Lake Walchensee was postulated by ecological data and supported by microphotographs. In this lakeSpumella sp. feeds on the nannoplanktic diatomCyclotella glomerata.     

Alimentation et facteurs de mortalité des larves de corégones (Coregonus sp.). Exemple de deux lacs de niveaux trophiques différents: Les lacs de Sarnen et de Hallwil (Suisse Centrale)

Whitefish larvae (Coregonus sp.) were caught at regular intervals in 1986 and 1987 in oligotrophic Lake Sarnen, and in 1987 in eutrophic Lake Hallwil.The food spectra of the larvae in each lake were directly related to the available prey organisms.The causes for the important decrease of the larval catches in Lake Sarnen observed in 1987 are examined.There was no significant difference in the abundance and size distribution of the principal zooplankton taxa between the 1986 and 1987 samples. The effects of a sudden cooling of the surface water layer on the survival of cold-bred whitefish larvae are discussed.     

Lake morphometry and wind exposure may shape the plankton community structure in acidic mining lakes

Acidic mining lakes (pH <3) are specific habitats exhibiting particular chemical and biological characteristics. The species richness is low and mixotrophy and omnivory are common features of the plankton food web in such lakes. The plankton community structure of mining lakes of different morphometry and mixing type but similar chemical characteristics (Lake 130, Germany and Lake Langau, Austria) was investigated. The focus was laid on the species composition, the trophic relationship between the phago-mixotrophic flagellate Ochromonas sp. and bacteria and the formation of a deep chlorophyll maximum along a vertical pH-gradient. The shallow wind-exposed Lake 130 exhibited a higher species richness than Lake Langau. This increase in species richness was made up mainly by mero-planktic species, suggesting a strong benthic/littoral - pelagic coupling. Based on the field data from both lakes, a nonlinear, negative relation between bacteria and Ochromonas biomass was found, suggesting that at an Ochromonas biomass below 50 μg C L⁻¹, the grazing pressure on bacteria is low and with increasing Ochromonas biomass bacteria decline. Furthermore, in Lake Langau, a prominent deep chlorophyll maximum was found with chlorophyll concentrations ca. 50 times higher than in the epilimnion which was build up by the euglenophyte Lepocinclis sp. We conclude that lake morphometry, and specific abiotic characteristics such as mixing behaviour influence the community structure in these mining lakes.     

三峡水库不同运行阶段澎溪河典型优势藻原位生长速率

在澎溪河高阳平湖半封闭库湾对不同生长策略的5种代表性藻种进行原位培养实验,初步探讨三峡水库不同运行阶段藻类原位生长速率和主要影响因素.结果表明,低水位时期,CR型生长策略的湖北小环藻(Cyclotella hubeiana)和兼具C、R、S型生长策略的卵形隐藻(Cryptomonas ovata)出现了正的生长速率特征,分别为0.128±0.006和0.210±0.010 d-1;高水位时期,湖北小环藻、CS型生长策略的空球藻(Eudorina sp.)、兼具C、R、S型生长策略的卵形隐藻具有较大原位生长速率,分别为0.175±0.009、0.326±0.016和0.187±0.009 d-1;泄水期,湖北小环藻、空球藻以及卵形隐藻依旧在较长时间内保持较高的原位生长速率,分别为0.231±0.012、0.281±0.014和0.406±0.020 d-1,但S型生长策略的铜绿微囊藻(Microcystis aeruginosa)随着水库泄水水位持续下降而逐渐体现出优势.低水位期影响上述藻种原位生长速率的主要因素为溶解性磷酸盐和水温.高水位时期影响显著的环境因素为颗粒态磷和研究水域最大风速.泄水期影响显著的环境因素为溶解性磷酸盐、溶解性无机氮和总氮.忽略藻类随流输移产生的干扰,不同生长策略藻种的原位生长速率与同期藻类群落演替特征具有一定关联.     

New discovery of Palaeontinid fossils from the Middle Jurassic in Daohugou, Inner Mongolia (Homoptera, Palaeontinidae)

Three new species of fossil Palaeontinidae are described from Daohugou Village, Inner Mongolia, China: Daohugoucossus shii sp. nov., D. parallelivenius sp. nov., D. lii sp. nov. The diagnosis of Dao- hugoucossus Wang, Zhang and Fang, 2006 is revised. These materials are the first complete fossil palaeontinids in the Middle Jurassic of the world. Based on observation of these new specimens, Sc of this new genus has the following combined characters: joined with R at base, diverged near M separa- tion, coalesced with R before the nodal line, extended beyond the nodal line and fused with R1 before distal end. Due to the Sc characteristics mentioned above, the genus Liaocossus Ren, Yin and Dou, 1998 can be well distinguished from “Ilerdocossus-complex”.     

Interaction between Epistylis sp. and copepods in tropical lakes: responses of epibiont infestation to species host density

Interaction between Epistylis sp. and copepods was investigated in 3 tropical lakes. Epibiont load was higher in Thermocyclops minutus compared to Notodiaptomus ssp. at light compensation depth. No difference was found at surface. Infestation of Epistylis sp. seems to respond to copepod species densities. Attaching to more abundant copepods may increase encounter rates of epibionts with its hosts, raising biological efficiency of it even if attaching to smaller hosts when rare larger ones are present.     

太湖冬季底泥中活体藻类的检测

2002年冬从太湖梅梁湾采集柱状底泥,取三段进行直接镜检和用MA培养基进行光照培养．镜检发现表层(0-3cm)底泥中有多种藻类细胞,中层(10-13cm)底泥的藻类细胞种类明显减少,下层(20-23cm)底泥中没有发现藻类细胞．底泥培养的结果与之有相似的趋势,但得到的活体藻类细胞的种类相应减少．培养3个月后得到在外观和群落结构上与夏季水华相似的群落．结果表明底泥中的微囊藻和小环藻在太湖底泥中具有良好的适应性,占有明显的优势地位,底泥可以作为水华蓝藻的越冬场所和来年水华的种源．     

洞庭湖荻-苔草群落交错带植被动态及影响因子——以北洲子洲滩为例

近年来,受全球变化及高强度人类活动的影响,洞庭湖湿地群落分布带不断下移,引发了人们对其湿地服务功能下降的担忧.以洞庭湖北洲子洲滩为例,采用野外样带调查和室内分析相结合的方法,对洞庭湖湿地荻-苔草群落交错带植被和环境特征进行研究,以期揭示荻-苔草群落交错带动态变化和影响其变化的关键环境因子.结果表明:土壤含水量随高程增加呈逐渐降低的趋势,土壤总碳、总氮、总磷含量和p H值在样带间差异显著,但土壤电导率和总钾含量在样带间无显著差异.各样带物种丰富度和香农指数随高程增加整体上呈先降低再增加的趋势.荻生物量随高程增加呈逐渐增加的趋势,而苔草生物量呈先增加后减少的趋势.典型相关分析表明,土壤含水量与二者生物量及群落丰富度、多样性间具有很好的相关性,表明土壤含水量是调控该群落交错带植被动态变化的关键环境因子.     

Les corégones du lac de Neuchâtel: rendement de la pêche; âge et croissance des individus capturés par les pêcheurs professionnels

The fishery of twoCoregonus sp. of the Lake of Neuchâtel (Switzerland) were studied with statistics held since 1917. The younger age structure observed in 1978–80 due to eutrophication which enabled a faster growing of the fishes permits to explain the decrease in fish numbers as well as in weight of the catches.     

Japan's earliest ostracods

Mesozoic, Cenozoic and especially Holocene ostracod faunas have been documented from Japan. Not surprisingly, considering the plate tectonic factors at play, very few ostracod faunas are known from its early Paleozoic successions. Our pilot studies have recovered new ostracod assemblages from early Paleozoic terranes of Japan. Acid preparation of carbonates has yielded low diversity, poorly preserved yet significant palaeocopid and podocopid ostracod faunas from Wenlock/Ludlow Series Silurian rocks at Gionyama in the Kurosegawa Terrane, Miyazaki Prefecture, Kyushu, and Hitoegane in the Hida‐Gaien Terrane, Gifu Prefecture, Honshu. The ostracod faunas include new eurychilinoid (Pauproles supparata gen. et sp. nov.), hollinoid (Hollinella orienta sp. nov.) and beyrichioid (Clintiella antifrigga sp. nov.) palaeocopid taxa. Conodonts recovered from the same sample as the ostracods from Gionyama confirm a mid‐Silurian age for the part of the Gionyama Formation in question. The ostracod faunas recovered from Gionyama and Hitoegane are the first confirmed, well‐documented record of the group from the Silurian of Japan and are therefore the earliest known ostracods from that country (a previous record of purported Ordovician ostracods from Japan is incorrect). The ostracod taxa display links with the paleocontinents of particularly Laurentia and Baltica and demonstrate a pan‐tropical signature; it appears that climate control was stronger than geographical control in shaping this pattern of ostracod distribution. The material recovered includes adult dimorphic (assumed sexual) pairs of three palaeocopid species, which represent Japan's oldest (423–433 million years) known ‘couples’.     

An endemic freshwater mussel species from the Orontes River basin in Turkey and Syria represents duck mussel’s intraspecific lineage: Implications for conservation

Amik Lake or, historically, Lake of Antioch, was a large freshwater body in the lower Orontes River basin (Hatay Province, Turkey) that was drained in the 1940s–1970s. Several endemic animal species were described from this lake, including the freshwater mussel Anodonta pseudodopsis Locard, 1883 (Bivalvia: Unionidae) characterized by a large rounded shell covered by a peculiar yellow or yellowish-brown periostracum. Molecular analyses of topotypes of this nominal taxon collected from the former lake’s tributaries in the Amik Plain indicate that it is an intra-specific lineage of the widespread Anodonta anatina (Linnaeus, 1758) based on the mitochondrial COI and 16S rRNA, and the nuclear 28S rRNA gene fragments. Geometric morphometric analyses using the lectotype and topotypes of Anodonta pseudodopsis support our DNA-based hypothesis on the status of this nominal taxon. A new synonymy is provided as follows: Anodonta anatina = Anodonta pseudodopsis syn. nov. The syntype of Anodonta pseudodopsis SMF 5129 “See von Antiochia” (Senckenberg Research Institute and Natural History Museum, Frankfurt, Germany) is designated here to be the lectotype of this nominal taxon. Finally, we conclude that Anodonta anatina range covers the Orontes River basin in Turkey and Syria and the Nahr al-Kabir al-Shamali River in the Latakia Governorate of Syria. This intraspecific lineage of Anodonta anatina and other freshwater mussels of the Middle East are highly threatened due to multiple anthropogenic impacts and must be a focus of international conservation efforts. The Karasu River in eastern Turkey hosts viable populations of all freshwater mussel species of the Orontes’s fauna and can be considered one of the most important water bodies for the conservation of these imperiled animals in the region.     

Two new species of Vestrogothia (Phosphatocopina, Crustacea) of Orsten-type preservation from the Upper Cambrian in western Hunan, South China

Although fossils of Orsten-type preservation represented by Skaracarida and Phosphatocopina were first reported from the Middle and Upper Cambrian in western Hunan, South China in 2005, diversified phosphatocopine species have never been appropriately described and elucidated in terms of their evolutionary relationships. Here, we described two new species of Phosphatocopina, Vestrogothia anterispinata sp. nov. and V. bispinata sp. nov. The evolutionary relationship among all the valid species of Phosphatoco...     

Evolution quantitative à long terme des rotifères au cours de l'eutrophisation du Lac Léman

Eutrophication in Lake Geneva (= Lake Léman) appears primarily as changes in chemical characteristics and plankton populations, inducing quantitative changes in the rotifer assemblages and species combinations.In the course of eutrophication, an increase of the rotifer abundance was found, together with settlement of new species and increase of eutrophication tolerant species, and despite the decrease or disappearance of eutrophication sensitive species.The new equilibrium in the trophic state of Lake Geneva related with the decreasing inputs of nutrients, induces a new structure and less abundance of the total pelagic rotatorian community.

     

New fossil eccoptarthrids (Coleoptera: Curculionoidea) from the Yixian Formation of western Liaoning, China

One new genus and three new species of the weevil family Eccoptarthridae (Curculionoidea), Leptocar polychaetus gen. et sp. nov., Abrocar macilentus sp. nov., Cretonanophyes punctatus sp. nov., are described and illustrated. They pertain to the Upper Jurassic or Lower Cretaceous Yixian Formation of western Liaoning Province, China. The host plants to the living eccoptarthrids and the floras in Yixian Formation indicate that those archaic eccoptarthrids possibly lived on conifers with a phylogenetic closeness to Cupressaceae. Besides, the early diversification of eccoptarthrids is discussed: origi- nated in Central or East Asia in the Late Jurassic, spread into Western Europe and South America during the Early Cretaceous, underwent a dramatic decline after the Early Cretaceous which likely was caused by competitive pressure and the displacement of their host plants.     

淮南采煤塌陷湖泊浮游植物优势种的营养动力学

在淮南潘谢矿区选取3个营养盐结构差异较大的塌陷湖泊,于2014—2015年4个季度分别对浮游植物群落结构组成进行调查,选取3个湖泊中的优势种(属)具尾蓝隐藻(Chroomonas caudata)、链形小环藻(Cyclotella catenata)和伪鱼腥藻(Pseudanabaena sp.)作为研究对象,设置不同的氮(N)、磷(P)浓度梯度进行营养动力学培养实验,并结合Monod方程,获得3个藻种在不同营养盐限制下的营养动力学参数.N限制下具尾蓝隐藻、小环藻和伪鱼腥藻的最大生长速率(μmax)和半饱和常数(Ks)分别为:0.66 d~(-1)、1.66 mg/L;0.37 d~(-1)、1.06 mg/L;0.71 d~(-1)、2.26 mg/L;P限制下它们的μmax和Ks则分别为:0.51 d~(-1)、0.023 mg/L;0.31 d~(-1)、0.035 mg/L;0.90 d~(-1)、0.015 mg/L.综上所述,在N充足时,伪鱼腥藻能够在竞争中形成优势,同时在P限制情况下易成为优势种,从营养动力学的角度揭示了其在塌陷湖泊中占据优势的营养盐动力学机制.研究结果可以为沉陷区水域开发利用和营养盐管理提供科学依据.     

The unique nature in ore composition,geological backgroudd and metallogenic mechanism of non-conventional superlarge ore deposits: A preliminary discussion

The new plants documented here, including a representative of the trimerophytesPsilophyton primitiuum sp. nov., a questionable rhyniophyte or trimerophyteHedeia sinica sp. nov., a prelycopodBragwanathia sp. and two species of zosterophyllophytes,Zosterophyllum australianum Lang and Cookson 1930 and2. sp. 1, from the Posongchong Formation of southeastern Yunnan, China, add to the known floral diversity of the Early Devonian of this region. Two sections of the Posongchong Formation, Changputang section of Wenshan district and Gegu section of Mengzi district also are introduced. After comparing the plants with those of the coeval flora of Australia and considering the data of recent paleocontinental reconstructions, the authors suggest that there is a northeastern Gondwana phytogeographic unit during the early Devonian comprising Australia, South China Block and perhaps Shan-Thai Block. The similarity of the floral component between Australia and South China is discussed. Because both Australia and South China also have dominant or endemic taxa, each might be recognized as a subunit, separately characterized byHedeia for Australia andEophyllophyton for South China. Project supported by the National Natural Science Foundation of China (Grant Nos. 49372075 and 49742004)     

九寨沟国家级自然保护区长海夏季浮游植物群落结构及生态评价

高山湖泊对于全球气候变化及人类影响是一个极为敏感的参照系统.九寨沟国家级自然保护区长海作为一个独特的高山湖泊,研究其浮游植物群落结构及其与环境的关系,评估其水质现状及影响因素,有着重要的意义.本文于2014年7月对长海浮游植物群落结构进行了研究.全湖共布设12个采样点,并在中心采样点进行了垂直分层采样.本次调查共发现浮游植物6门38属63种,平均丰度为6.98×10~5cells/L,平均生物量为0.31 mg/L.浮游植物的水平分布差异不大;在垂直分布上,浮游植物的丰度从表层0.5 m至水下50 m呈现先增加后减少的趋势,在20 m水深处达到最大.长海浮游植物的优势种是长海小环藻(Cyclotella changhai)和飞燕角甲藻(Ceratium hirundinella),长海小环藻数量较多,飞燕角甲藻生物量较大.长海浮游植物多样性指数较低,综合各类水质评价方法,可以得出九寨沟长海处于贫-中营养状态.     

Eutrophisation et faune benthique de trois lacs de montagne

Zoobenthic communities were used to indicate the trophic state of three mountain lakes of western Switzerland. In these lakes, the macrobenthos was constituted mainly by oligochaetes and chironomid larvae;Tubifex tubifex was the most abundant worm species. In Lakes Lioson and Hongrin, the abundance of zoobenthos did not change or increased slightly with depth andStylodrilus heringianus was present. In Lake Chavonnes, zoobenthos decreased strongly with depth and it consisted mainly ofTubifex tubifex. These data, compared with those from other oligotrophic lakes, indicated that Lake Chavonnes was eutrophic whereas Lakes Lioson and Hongrin were oligotrophic. However, Lake Hongrin—an artificial lake made in 1968—constituted a special case. Its water comes in part from mountain rivers and in part from Lake Geneva. Consequently, some benthic species of Lake Geneva have colonized Lake Hongrin and its water is warmer than in a typical mountain lake.