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1.
During November 2000, a collection of acanthocephalans from birds in Quang Ninh Province, Vietnam, included a new genus and species in a new family and order. Pyrirhynchus heterospinus n. gen., n. sp. (Pyrirhynchidae n. fam.: Heteramorphida: new order) is described from Actitis hypoleucos (Linnaeus, 1758) (common sandpiper). The new family combines characters from Polymorphidae and Heteracanthocephalidae, and it includes new features. Specimens of the new species are distinguished from those of Heteracanthocephalidae and/or Polymorphidae by their long cylindrical trunk with anterior swelling, pyriform proboscis with hooks much larger ventrally, brain at the anterior end of the receptacle, specialized tubular cement glands, and elliptoid eggs with concentric shells. A detailed analysis of proboscis and trunk armature is included, and specimens of several species of Arhythmorhynchus Lühe, 1911 (Polymorphidae) were studied for comparative purposes. The proboscis of P. heterospinus is armed with 17 to 20 rows of 17 to 19 hooks each, with anterior 9-11 hooks rooted and posterior 6-10 spines rootless. 相似文献
2.
In 2003, the parasite fauna of 197 European eels Anguilla anguilla, captured at three different locations (Laufenburg, Karlsruhe and Beneeden Leeuwen) in the River Rhine, was analysed. The eels harboured a total of 18 species, among them the protozoa (Myxidium giardi, Myxobolus kotlani and Trypanosoma granulosum), acanthocephalans (Acanthocephalus anguillae, Acanthocephalus lucii, Echinorhynchus truttae, Pomphorhynchus laevis), nematodes (Paraquimperia tenerrima, Pseudocapillaria tomentosa, Camallanus lacustris, Raphidascaris acus, Spinitectus inermis and Anguillicola crassus), cestodes (Bothriocephalus claviceps and Proteocephalus macrocephalus) and monogeneans (Pseudodactylogyrus sp.). The parasite fauna at the different locations is discussed with respect to the crustacean fauna present at these locations. The investigation shows that changes in the composition of the crustacean fauna, due to the anthropogenic breakdown of a biogeographic barrier, are reflected in the composition of the intestinal eel parasite fauna. 相似文献
3.
Vonlanthen P Excoffier L Bittner D Persat H Neuenschwander S Largiadèr CR 《Molecular ecology》2007,16(21):4572-4584
Natural colonizations across watersheds have been frequently proposed to explain the present distributions of many freshwater fish species. However, detailed studies of such potential watershed crossings are still missing. Here, we investigated potential postglacial watershed crossings of the widely distributed European bullhead (Cottus gobio L.) in two different areas along the Rhine–Rhône watershed using detailed genetic analysis. The main advantage of studying bullheads vs. other freshwater fish species is that their distribution has been lightly influenced by human activities and as such, interpretations of colonization history are not confounded by artificial transplantations. The genetic analyses of eight microsatellite loci revealed strong genetic similarities between populations of both sides of the Rhine–Rhône watershed in the Lake Geneva area, giving strong evidence for a natural watershed crossing of bullheads from the upper Rhine drainage into the Rhône drainage in the Lake Geneva area likely facilitated by the retreat of the glaciers after the last glacial maximum some 20 000 years ago. Populations from the Lake Geneva basin were genetically more similar to populations from across the watershed in the upper Rhine drainage than to populations further downstream in the lower Rhône. In contrast, populations from Belfort, an area, which was not covered by ice during the last glacial maximum, showed strong genetic differentiation between populations of the upper Rhine and Rhône drainages. Based on our results on the bullhead, we propose that glacial retreat may have eased the dispersal of numerous European freshwater fish species across several geological boundaries. 相似文献
4.
利用光学显微镜和扫描电镜首次对云南省楚雄州晚中新世石灰坝组石鼓村层的钙化木材进行了解剖学研究.鉴定出两种类型的木材:柳杉型落羽杉型木(Taxodioxylon cryptomeripsoides Schonfeld)和杉木型落羽杉型木(Taxodioxylon cunninghamioides Watari).二者分别与现代柳杉属和杉木属具有最接近的亲缘关系.根据这两种杉科化石木现存最近亲缘种的生态环境,并综合其他资料,推测该地区在晚中新世为温暖湿润的亚热带气候环境. 相似文献
5.
对中国云南百合科一新种———粗穗球子草Peliosanthes pachystachya W.H.Chen&Y.M.Shui进行了描述和绘图。该新种的匍匐茎具长约18cm的节间,与匍匐球子草P.sinica Wang&Tang接近,但因叶具9-13条叶脉,花梗长9-10mm,无小苞片,花被片卵状三角形而明显不同。该新种因花被片卵状三角形,苞片披针形,也近似于长苞球子草P.ophiopogonoides Wang&Tang,但匍匐茎长,叶具9-13条叶脉,花梗长9-10mm,花葶和花序均较短而不同。 相似文献
6.
7.
Long-term Developments in Ecological Rehabilitation of the Main Distributaries in the Rhine Delta: Fish and Macroinvertebrates 总被引:2,自引:2,他引:0
Significant anthropogenic pressure in the Dutch part of the River Rhine is present from the 12th century. River engineering
and water pollution were the main stress factors for flora and fauna. From the middle of the 20th century measures were taken
to reduce water pollution. Recently, from 1987 onwards, these activities were put into a wider context of ecological river
rehabilitation. Effects of improvements on fish and macroinvertebrates in the main distributaries in the Rhine delta are reviewed.
The conclusions are that (a) most of the alterations in the Rhine delta are irreversible due to hard socio-economic boundary
conditions (e.g. safety, navigation); (b) chances for the development of riverine biotopes have therefore to be found in the
forelands and not in the main channels of the Rhine delta; (c) further reduction of pollutants, especially thermal pollution,
is needed to help original species to colonise the Rhine delta again; (d) non-indigenous species clearly leave a mark on recolonisation
possibilities of original species. 相似文献
8.
Length–weight relationships of 10 fish species from a Ganga River Basin tributary,Uttarakhand, India
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Length‐weight relationships (LWRs) are described for 10 fish species belonging to three families from the Gaula River, a tributary of the Ganga River Basin in India. LWRs for these species were unknown to FishBase, and new maximum lengths are recorded for one species. These results will be useful for fishery research, management and conservation in the least‐explored tributary of the Ganga River Basin. 相似文献
9.
In 1996, the Australian cotton industry adopted Ingard that expresses the Bacillus thuringiensis (Bt) toxin gene cry1Ac and was planted at a cap of 30%. In 2004-2005, Bollgard II, which expresses cry1Ac and cry2Ab, replaced Ingard in Australia, and subsequently has made up >80% of the area planted to cotton, Gossypium hirsutum L. The Australian target species Helicoverpa armigera (Hübner) and Helicoverpa punctigera (Wallengren) are innately moderately tolerant to Bt toxins, but the absence of a history of insecticide resistance indicates that the latter species is less likely to develop resistance to Bt cotton. From 2002-2003 to 2006-2007, F2 screens were deployed to detect resistance to CrylAc or Cry2Ab in natural populations of H. punctigera. Alleles that conferred an advantage against CrylAc were not detected, but those that conferred resistance to Cry2Ab were present at a frequency of 0.0018 (n = 2,192 alleles). Importantly, the first isolation of Cry2Ab resistance in H. punctigera occurred before significant opportunities to develop resistance in response to Bollgard II. We established a colony (designated Hp4-13) consisting of homozygous resistant individuals and examined their characteristics through comparison with individuals from a Bt-susceptible laboratory colony. Through specific crosses and bioassays, we established that the resistance present in Hp4-13 is due to a single autosomal gene. The resistance is fully recessive. Homozygotes are able to survive a dose of Cry2Ab toxin that is 15 times the reported concentration in field grown Bollgard II in Australia (500 microg/ml) and are fully susceptible to Cry1Ac and to the Bt product DiPel. These characteristics are the same as those described for the first Cry2Ab resistant strain of H. armigera isolated from a field population in Australia. 相似文献
10.
A. V. Yankovsky 《Entomological Review》2006,86(2):240-246
Eleven blackfly species were collected in the southern part of the Lapland State Biosphere Nature Reserve. Among these, six species, Prosimulium macropyga (Lundström, 1911), Boreosimulium annulus (Lundström, 1911), Schoenbaneria pusilla (Fries, 1824), Odagmia rotundata Rubzov, 1956, Archesimulium tuberosum (Lundström, 1911), and Argentisimulium noelleri (Friederichs, 1920) are common in this region; Archesimulium polare (Rubzov, 1940) is recorded from the Kola Peninsula for the first time; Gnus decimatum (Dorogostajsky et al., 1935) is recorded from the northern part of European Russia for the first time. A new species, Argentisimulium tshuni sp. n., is described from the male, larva, and pupa. The diagnostic characters of the new species are as follows. The male differs from those of the all other species in the presence of a conical projection in the distal part of the gonostylus, absence of an apical spine, presence of one very large spine in the parameres, and shorter gonostylus. In addition, the male differs from most of the congeners in the obsolete basal wrinkled part of the gonofurca. The larva differs from those of the majority of the related species in the presence of only one row of the inner mandibular spines. Records of two species, Helodon ferrugineus (Wahlberg, 1844) and Stegopterna trigonia (Lundström, 1911), identified from a few early-instar larvae, need confirmation. The type material of the new species is deposited at the Zoological Institute, Russian Academy of Sciences, St. Petersburg. 相似文献
11.
基于多基因片段的系统发育分析显示,山西省吕梁山区俗称为大把子的一种传统野生食用蘑菇是隶属于假杯伞科Pseudoclitocybaceae杯桩菇属Clitopaxillus的一个分类学新物种,本研究将其定名为大把子杯桩菇C. dabazi。该种与分布于欧洲的C. alexandri和C. fibulatus形态特征相似并且有密切的亲缘关系。大把子杯桩菇的鉴别特征为菌盖半球形,菌盖边缘稍内卷,土黄褐色至灰白褐色,菌柄粗棒状,具蘑菇香味。大把子杯桩菇在秋季发生,在整个吕梁山脉均有分布,在中北部的管涔山、关帝山区域,主要生长于云杉Picea sp.、落叶松Larix sp.林内的草地上;而在南部的五鹿山一带,则发生于松Pinus sp.、栎Quercus spp.混交林内草地上。本文还提供了杯桩菇属已知3个物种的分种检索表。 相似文献
12.
根据2018-2020年澜沧江西双版纳段5次鱼类资源调查数据,结合相关文献资料,对该流域鱼类组成及物种多样性进行了分析。结果显示:澜沧江西双版纳段此次共调查到鱼类119种,隶属于11目28科79属,而历史记录鱼类共179种,隶属于12目34科106属。随着调查的不断深入,土著鱼类种数逐渐增多,但占比却逐渐下降,外来鱼类种数逐渐增多,占比也逐渐升高;本次调查到土著鱼类92种,占鱼类种数的77.31%,占比进一步下降;外来鱼类27种,占鱼类种数的22.69%,占比进一步升高。该区域鱼类优势种为云南吻孔鲃Poropuntius huangchuchieni和少鳞舟齿鱼Scaphiodonichthys acanthopterus,常见种为长臀鲃Mystacoleucus marginatus和宽额鳢Channa gachua。有《国家重点保护野生动物名录》(2021年)鱼类5种,《中国生物多样性红色名录脊椎动物卷》(2015年)受威胁鱼类8种。相对于我国其他江河,澜沧江西双版纳段有极高水平的鱼类物种多样性,其中澜沧江干流鱼类物种多样性相对于左、右岸支流较低,左岸支流鱼类多样性高于右岸,罗梭江鱼类多样性高于其他一级支流。虽然澜沧江西双版纳段鱼类物种多样性维持在较高水平,但土著鱼类占比下降趋势明显,仍面临着严重威胁,本文分析了受威胁因素,并提出了保护建议。 相似文献
13.
Smales LR 《The Journal of parasitology》2007,93(2):392-398
In a survey of 1,732 amphibians and reptiles collected across S?o Paulo Province, Brazil, and 7 provinces in Paraguay, 26 species were found infected with acanthocephalans. Of 1,510 anurans, 14 anurans, representing 11 species, were infected with cystacanths of Centrorhynchus spp. and 1 anuran with cystacanths of Oligacanthorhynchus sp. Of 107 lizards, 1 lizard was infected with cystacanths of Centrorhynchus sp. and 1 lizard with cystacanths of Oligacanthorhynchus sp. Acanthocephalus caspanensis was found in 3 anurans (3 species) and Acanthocephalus lutzi in 3 anurans (2 species) and 2 snakes (2 species). The systematic position of A. lutzi cannot be resolved using presently available morphological data. Acanthocephalus saopaulensis n. sp. was found in a single individual of Bufo ictericus. The new species can be differentiated from all its congeners except A. caspanensis in having a sigmoid-shaped male posterior end and from A. caspanensis in having a proboscis armature of 16 rows of 5-7 hooks rather than 18-19 rows of 6-7 hooks and larger eggs. The status of Acanthocephalus and Pseudoacanthocephalus continues to be problematic. 相似文献
14.
van Nieukerken EJ Wagner DL Baldessari M Mazzon L Angeli G Girolami V Duso C Doorenweerd C 《ZooKeys》2012,(170):29-77
A grapevine leafminer Antispila oinophylla van Nieukerken & Wagner, sp. n., is described both from eastern North America (type locality: Georgia) and as a new important invader in North Italian vineyards (Trentino and Veneto Region) since 2006. The species is closely related to, and previously confused with Antispila ampelopsifoliella Chambers, 1874, a species feeding on Virginia creeper Parthenocissus quinquefolia (L.) Planchon., and both are placed in an informal Antispila ampelopsifoliella group. Wing pattern, genitalia, and DNA barcode data all confirm the conspecificity of native North American populations and Italian populations. COI barcodes differ by only 0-1.23%, indicating that the Italian populations are recently established from eastern North America. The new species feeds on various wild Vitis species in North America, on cultivated Vitis vinifera L. in Italy, and also on Parthenocissus quinquefolia in Italy. North American Antispila feeding on Parthenocissus include at least two other species, one of which is Antispila ampelopsifoliella. Morphology and biology of the new species are contrasted with those of North American Antispila Hübner, 1825 species and European Holocacista rivillei (Stainton, 1855). The source population of the introduction is unknown, but cases with larvae or pupae, attached to imported plants, are a likely possibility. DNA barcodes of the three European grapevine leafminers and those of all examined Heliozelidae are highly diagnostic. North American Vitaceae-feeding Antispila form two species complexes and include several as yet unnamed taxa. The identity of three out of the four previously described North American Vitaceae-feeding species cannot be unequivocally determined without further revision, but these are held to be different from Antispila oinophylla. In Italy the biology of Antispila oinophylla was studied in a vineyard in the Trento Province (Trentino-Alto Adige Region) in 2008 and 2009. Mature larvae overwinter inside their cases, fixed to vine trunks or training stakes. The first generation flies in June. An additional generation occurs from mid-August onwards. The impact of the pest in this vineyard was significant with more than 90% of leaves infested in mid-summer. Since the initial discovery in 2006, the pest spread to several additional Italian provinces, in 2010 the incidence of infestation was locally high in commercial vineyards. Preliminary phylogenetic analyses suggest that Antispila is paraphyletic, and that the Antispila ampelopsifoliella group is related to Coptodisca Walsingham, 1895, Holocacista Walsingham & Durrant, 1909 and Antispilina Hering, 1941, all of which possess reduced wing venation. Vitaceae may be the ancestral hostplant family for modern Heliozelidae. 相似文献
15.
A data set on intestinal helminth parasites was collected in the course of an 18 year investigation into the biology of eels in Meelick Bay, Lough Derg, River Shannon. This was used to test two hypotheses relating to the composition and structure of intestinal helminth communities, namely that eels in large rivers do not harbour richer and more diverse communities than those in small rivers but that community composition and structure are more stable over time than in small rivers. The helminth community was species poor, with only six species comprising the component community and a maximum infracommunity richness of three species. The community was overwhelmingly dominated by the acanthocephalan Acanthocephalus lucii, reflecting the importance of its intermediate host Asellus aquaticus in the eels' diet. The remaining helminth species contributed to species richness but made very little contribution to community diversity. Population levels of Acanthocephalus lucii fell and remained low between 1992 and 2000, probably reflecting increased movement of eels from other parts of the lough into Meelick Bay. Diversity values were low, but similar to those reported from other rivers in Britain and Europe. The results provided support for both hypotheses and indicated that in respect of richness, diversity and dominance, the helminth communities of eels in the River Shannon were typical of, and comparable to, those of other large rivers throughout Europe. 相似文献
16.
Fish zonations and guilds as the basis for assessment of ecological integrity of large rivers 总被引:2,自引:2,他引:0
Longitudinal zonation concepts describe the downstream changes in chemico-physical and biological properties of rivers. Including information on ecological fish guilds can enhance the usefulness of fish zonation concepts, in a way that they can be used as tools for assessment and management of the ecological integrity of large rivers. We present an ecological characterization of fish zones and fish communities in near-natural and in regulated large rivers in Europe (the River Doubs in France and the Rivers Rhine and Meuse in the Netherlands), using guild classifications of several life-history traits of fish and national Red Lists of threatened species. The Doubs data set was also analyzed using indices of the sensitivity of fish species to environmental degradation and indices for eurytopy. In these rivers, the number of ecological guilds per zone increases downstream, and there are clear shifts in the structure of the guilds. Flow preference and reproduction ecology of river fish are closely linked. The proportion of rheophilic species in the fish community decreases downstream, and the proportions of limnophilic and eurytopic species increase. Lithophilic and psammophilic spawners are dominant in the upper zones, whereas the lower zones are dominated by phytophilic and phytolithophilic spawners. The proportion of zoobenthivorous and periphytivorous species decreases downstream, and the proportion of zooplanktivorous and phytivorous species increases. However, because the European fish fauna mainly consists of feeding generalists, the discriminative abilities of simplistic feeding guild classifications are not very high. Guilds of sensitive, stenoecious species that share life history strategies that are highly adapted to specific riverine conditions (rheophils and limnophils) have declined far more than generalist species that can survive in a wide range of habitats that are not characteristic of natural river ecosystems. Because of the subsequent over-abundance of the eurytopic species the original longitudinal fish zonations are hardly recognizable anymore in heavily impacted large rivers such as the River Rhine. Hence these rivers do not meet the criteria for ecological integrity. Within a specific fish region, a suitable way of analyzing and monitoring the impact of human disturbance on the structure of the fish community is by comparing the guild structure of the present state of a fish zone with that of the reference situation. 相似文献
17.
Nolte AW Freyhof J Stemshorn KC Tautz D 《Proceedings. Biological sciences / The Royal Society》2005,272(1579):2379-2387
Fish abundance surveys in the Rhine system have shown in the past two decades that there is a rapid upriver invasion of a freshwater sculpin of the genus Cottus. These fish are found in habitats that are atypical for the known species Cottus gobio, which is confined to small cold streams within the Rhine drainage. Phylogeographic analysis based on mitochondrial haplotypes and diagnostic single nucleotide polymorphisms indicates that the invasive sculpins are hybrids between two old lineages from the River Scheldt drainage and the River Rhine drainage, although it is morphologically more similar to the Scheldt sculpins. Most importantly, however, the invasive population possesses a unique ecological potential that does not occur in either of the source populations from the Rhine or the Scheldt, which allows the colonization of new habitats that have previously been free of sculpins. Microsatellite analysis shows that the new lineage is genetically intermediate between the old lineages and that it forms a distinct genetic group across its whole expansion range. We conclude that hybridization between long separated groups has lead to the fast emergence of a new, adaptationally distinct sculpin lineage. 相似文献
18.
We have recently identified two novel cysteine proteinase inhibitors from the skin of Atlantic salmon (Salmo salar L.), named salmon kininogen and salarin. In preliminary experiments, the proteins were found to be both N- as well as O-glycosylated. In the present study we show that both proteins carry biantennary alpha2,3-sialylated N-glycans. A very high amount of O-acetylated Neu5Ac units are present in the N-glycans, comprising about 60% di-O-acetylated species. Non-O-acetylated Neu5Ac make up less than 5% of the sialic acids in the N-glycans. A small number of Neu5Acalpha2-8Neu5Ac structures were observed in the N-glycans as well. O-glycans from both proteins were recovered by reductive beta-elimination and were identified by mass spectrometric methods as mono- and disialylated core type 1 tri- and tetrasaccharides. The method used for O-glycan isolation prevented the identification of possible O-acetylation in the O-glycan-bound sialic acids, but O-acetylation was observed in one O-glycosylated peptide isolated from trypsin digest of salarin. The chemical nature of the sialic acid modifications was further studied by liquid chromatography tandem mass spectrometry of 1,2-diamino-4,5-methylenedioxybenzene-derivatized sialic acids, revealing 7-, 8-, and 9- but no 4-O-acetylation. To our knowledge, these are the first observations of sialic acid O-acetylation in N-glycans on fish species and represent clearly the most extensive N-glycan O-acetylation described on any species. 相似文献
19.
Tracing recent invasions of the Ponto-Caspian mysid shrimp Hemimysis anomala across Europe and to North America with mitochondrial DNA 总被引:1,自引:1,他引:0
The mysid crustacean Hemimysis anomala ('bloody-red shrimp') is one of the most recent participants in the invasion of European inland waters by Ponto-Caspian species. Recently the species also became established in England and the Laurentian Great Lakes of North America. Using information from mitochondrial cytochrome oxidase I (COI) gene sequences, we traced the invasion pathways of H. anomala ; the inferences were enabled by the observed phylogeographical subdivision among the source area populations in the estuaries of the Ponto-Caspian basin. The data distinguish two routes to northern and western Europe used by distinct lineages. One route has been to and through the Baltic Sea and further to the Rhine delta, probably from a population intentionally introduced to a Lithuanian water reservoir from the lower Dnieper River (NW Black Sea area) in 1960. The other lineage is derived from the Danube delta and has spread across the continent up the Danube River and further through the Main–Danube canal down to the Rhine River delta. Only the Danube lineage was found in England and in North America. The two lineages appear to have met secondarily and are now found intermixed at several sites in NW Europe, including the Rhine and waters linked with the man-made Mittellandkanal that interconnects the Rhine and Baltic drainage systems. 相似文献
20.
The middle section of the lake basin of the Doce River in Minas Gerais State, Brazil is plagued by grave environmental problems, including the introduction of non-native fish, which reduces the biodiversity of this region. This study reports the presence of two newly-detected non-native species in the Doce River Basin. Sampling efforts included gill nets with mesh size of 3 to 12 mm (measured diagonally) and trawling nets, both of which were used in independent field campaigns in 2002 and 2011. The two new invasive Perciform fishes, Plagioscion squamosissimus (Heckel 1840) and Parachromis managuensis (Günther 1867) were collected in Caratinga and Rio Doce municipalities. These records and other reports on non-native fishes suggest favorable environmental conditions for the establishment of invasive species in this drainage. These invasive species have behavior and diet observed in other wide distribution exotic fish of Rio Doce Basin representing a threat to the 77 native fishes of this region, 37 of which are endangered. 相似文献