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1.
This study describes the species diversity, abundance and biomass of gastropods in the ecosystems of the southern part of Western Siberia (Karasuk River and Krotovo Lake, Karasukskii district, Novosibirsk Oblast). Eighteen species belonging to seven families were recorded, Lymnaeidae, Planorbidae, Bulinidae, Bithynhdae, Physidae, Succineidae, and Zonitidae. The percentage of Bithyniidae snails was assessed in comparison to other gastropods and in regard to the species diversity, abundance, and biomass. The role of Bithyniidae mollusks as a host for trematodes was assessed. The biodiversity of mollusks and trematodes was studied using the Shannon-Weaver index.  相似文献   

2.
The Planorbidae is the largest family of freshwater pulmonate snails, yet an understanding of their intrafamily phylogenetic relationships is lacking and existing inferences are tentative. Moreover, it has been suggested that the Ancylidae, limpet-like freshwater pulmonates, should be merged with Planorbidae according to analysis of internal organ morphology. The present study explicitly tests this hypothesis by phylogenetic inference from partial DNA sequences of three molecular markers, nuclear ribosomal small subunit 18S and the mitochondrial cytochrome oxidase, and large subunit 16S. A molecular phylogeny was inferred based upon 22 taxa representing 12 ancylid and planorbid genera; additional taxa were included from the authors' database and from available sequences from GenBank, to further explore this basic data set. Taxa from Acroloxidae, Lymnaeidae, and Physidae were used as outgroups. Ancylidae and Planorbidae were found to be paraphyletic, with Planorbidae including some members of Ancylidae. "Ancyloplanorbidae" was also found to be paraphyletic because Acroloxus (Acroloxidae) surprisingly was included. Burnupia was found to be ancestral to "Ancyloplanorbidae" (including Acroloxus). The following clades of Planorbidae were supported: Bulininae and Planorbinae, Biomphalarini (including Helisoma and Planorbarius), and Planorbini and Segmentini.  相似文献   

3.
Pulmonate and prosobranch gastropods collected in Minnesota and Washington were examined for the presence of coccidian parasites. Typical coccidian oocysts were recovered from the feces of 89 of 543 (16%) pulmonate snails representing the families Lymnaeidae, Physidae, Planorbidae, and Succineidae. No coccidial infections were apparent in 104 specimens representing the prosobranch families Viviparidae and Pleuroceridae. Oocysts identified as Pfeifferinella ellipsoides were recovered from 21 of 101 (21%) Stagnicola elodes, 2 of 94 (2%) Physa gyrina, and 4 of 67 (6%) Aplexa hypnorum although incidence of infection differed greatly (2–40%) dependent upon the locality sample. This coccidian has not been described previously from North America and is reported here from members of the families Lymnaeidae and Physidae for the first time. Twenty percent of Oxyloma retusa from one habitat were shedding oocysts slightly smaller than, but otherwise identical with, those of Alveocystis gugleri. A third as yet unidentified oocyst was recovered from up to 54% of Helisoma trivolvis. As a group, the coccidia of pulmonate molluscs have been poorly studied. The findings of this survey, however, suggest that these parasites may be more common and widely distributed in both the Basommatophora and Stylommatophora than previously believed.  相似文献   

4.
Aquifers dominated by Pleistocene basalts and Jurassic to Cretaceous calcareous rocks feed the Hula basin which is drained by the Jordan River into Lake Kinneret. The sedimentary sequence of Lower-Middle Pleistocene Benot Ya‘akov Formation (BYF) exposed by excavations of the 0.78 Ma lake-side site of Gesher Benot Ya‘aqov (GBY) consists of six cycles representing ca. 100 ka history of the Hula basin. This study characterizes the types of water sources in the catchment, tests the use of the Strontium (Sr) isotopes in the common extant snail Melanopsis sp. as a tracer for water in its habitat, and uses this tracer in the fossil specimens from GBY to investigate the palaeohydrology of the Hula paleolake during the corresponding period.The Sr isotope composition (87Sr/86Sr) of extant Melanopsis shells in the Hula catchment range widely (0.7046-0.7079). These analyses define distinct groups of water sources and aquifers, while the Jordan River at the GBY site has values around 0.70685. The values for fossil Melanopsis from GBY vary along stratigraphy; they are highest around 0.70710 in Cycles 1 and 2, decrease to around 0.70685 in Cycle 3, and exhibit upward trending fluctuations in the subsequent cycles to 0.70703 in Cycle 6. This trend reveals the dominance of the Hermon Jurassic aquifer during the earlier, colder periods before the Matuyama-Brunhes Boundary (MBB) and enhanced influence of the Golan basaltic aquifers, in subsequent warmer periods, indicating that the MBB coincides with climate warming as supported by other indicators. Hence, this global geochronological indicator of 0.78 Ma is also potentially a global palaeoclimatic marker. The similarity between the Sr isotope composition of the Jordan River waters and Melanopsis and those from Cycle 3 suggests that the current climate corresponds to that of the warmest period within the record of GBY, clarifying the comparative interpretation of this 100 k.yr. climate record.  相似文献   

5.
The taxonomy of freshwater pulmonates (Hygrophila) has been in a fluid state warranting the search for new morphological criteria that may show congruence with molecular phylogenetic data. We examined the muscle arrangement in the penial complex (penis and penis sheath) of most major groups of freshwater pulmonates to explore to which extent the copulatory musculature can serve as a source of phylogenetic information for Hygrophila. The penises of Acroloxus lacustris (Acroloxidae), Radix auricularia (Lymnaeidae), and Physella acuta (Physidae) posses inner and outer layers of circular muscles and an intermediate layer of longitudinal muscles. The inner and outer muscle layers in the penis of Biomphalaria glabrata consist of circular muscles, but this species has two intermediate longitudinal layers separated by a lacunar space, which is crossed by radial and transverse fibers. The muscular wall of the penis of Planorbella duryi is composed of transverse and longitudinal fibers, with circular muscles as the outer layer. In Planorbidae, the penial musculature consists of inner and outer layers of longitudinal muscles and an intermediate layer of radial muscles. The penis sheath shows more variation in muscle patterns: its muscular wall has two layers in A. lacustris, P. acuta, and P. duryi, three layers in R. auricularia and Planorbinae and four layers in B. glabrata. To trace the evolution of the penial musculature, we mapped the muscle characters on a molecular phylogeny constructed from the concatenated 18S and mtCOI data set. The most convincing synapomorphies were found for Planorbinae (inner and outer penis layers of longitudinal muscles, three-layered wall of the penis sheath). A larger clade coinciding with Planorbidae is defined by the presence of radial muscles and two longitudinal layers in the penis. The comparative analysis of the penial musculature appears to be a promising tool in unraveling the phylogeny of Hygrophila.  相似文献   

6.
The site of Longgupo is located north of the subtropical zone and is part of the domain of eastern fauna. The large number of mammal species identified at this site enables clarification of the broad pattern of paleoenvironmental change for the three assemblages from the first stratigraphic sequence (Huang W.-B. excavations). The different species have been classified in four biogeographic groups: subtropical (moderate monsoon), tropical forest (hot and humid climate), montane (cold climate) and prairie (cold and dry climate). Variation in the representation rate of each of these groups enables general reconstruction of the paleoenvironments for the three assemblages identified at Longgupo: a lower assemblage in a hot and humid climate with cold and dry episodes, an intermediate assemblage in a rather cold and dry climate in the lower part, becoming progressively warmer and humid toward the top of the sequence with a monsoon influence more marked than the present day, and an upper assemblage in a rather cold and dry climate. This biochronology and general paleoenvironmental reconstruction are clearly important, but as mentioned above, the stratum by stratum correspondence between the old and new stratigraphic sequences has been quite difficult because the position of material recovered during the early excavations was not recorded.  相似文献   

7.
Hundreds samples of the charcoals and waterlogged woods excavated from three late Paleolithic sites (Suyanggae, Gunang-gul and Sorori) in the Jungwon Region in Korea were analyzed to reconstruct the vegetation and paleoclimate in the region. Analyzed charcoal samples from the Suyanggae site show that the climate was cold in the lower part and it became more warm and dry in the upper part. From the Gunang-gul site, only Picea spp. was identified, indicating cool climates. From the Sorori site, two species were found; Alnus spp. (95%) and Ulmus spp. (5%). No conifers were discovered. The species composition indicates that the climate condition of central Korean peninsula around 8,800 BP was little cooler and wetter condition.  相似文献   

8.
贵州白鹇湖沉积物中孢粉记录的5.5kaB.P.以来的气候变化   总被引:1,自引:0,他引:1  
杜荣荣  陈敬安  曾艳  朱正杰 《生态学报》2013,33(12):3783-3791
通过对白鹇湖沉积物柱芯孢粉组合的剖面变化分析,在有机质14C定年基础上,探讨了白鹇湖地区过去5.5 ka calB.P.以来的植被演替和气候变化过程.研究结果表明,5500-4500 aB.P.期间,各类植被比较丰富,气候温暖湿润;4500-2750 aB.P.期间,干旱草本和蕨类植物开始出现,是气候转变过渡期;2750-1500 aB.P.期间,木本植物组合类型发生明显变化,喜湿草本减少,耐旱草本增加,气候向温凉干旱化发展;1500 aB.P.至今,木本植被和喜湿草本继续减少,中生耐旱草本和蕨类植物数量继续大幅增加,干旱化趋势明显,植被组合向典型石漠化植被组合类型发展.白鹇湖沉积物剖面孢粉组合变化表明,该地区近5000a来气候变化以温度下降、降水减少为主要趋势,并存在明显的陆地植被退化现象.研究还揭示了自然气候变化事件(如气候持续干旱)可导致喀斯特地区发生石漠化,证实了喀斯特地区生态环境具先天脆弱性.科学评估白鹇湖地区气候干旱化趋势及其生态环境影响对指导该地区科学应对气候变化具重要意义,亟待加强.  相似文献   

9.
The objective of the present paper is to recognize and reconstruct, from the analysis of pollen recovered from sedimentary cores, the predominant plant communities and their variations during the Holocene in Corrientes Argentina, in order to infer changes in climatic conditions, vegetation and paleoenvironmental evolution in the northeast of Argentina. For this study, lakes located in the central region of Corrientes province were selected, comprising part of the western margin of the Iberá Wetland. The palynological analysis of the paleocommunities shows, in a first stage of the mid Holocene, the predominance of marsh grasslands and hygrophilous communities that indicates humid to sub‐humid environmental conditions. In a later stage of the mid Holocene, the paleocommunities show a characteristic association of wetlands, which together with the presence of Typha sp., would indicate sub‐humid to humid conditions and waterlogged or flooded soils with slow‐moving water. For the late Holocene, the paleocommunities show, initially, the presence of a grass‐dominated herbaceous steppe, indicating environmental disturbances, which in the fossil record could reflect the combination of intense wind action under a dry climate. In a later stage, the frequency and variety of species characteristic of humid environments increase, dominated by marshy‐herbaceous species, in addition to the development of the hygrophilous forest. Consequently, since the mid Holocene, the main climate factors responsible for the observed changes in wetland conditions were the location and intensity of the Atlantic and Pacific anticyclones in addition to changes in sea level. These forces mainly affected the distribution of precipitation, causing significant changes in the vegetation communities.  相似文献   

10.
The Permian section outcropping at Guardia Pisano (Sulcis area, SW Sardinia), comprises two successions, separated by an unconformity. The lower succession is composed of grey-black sandy shales, rich in plant remains and in sporomorphs, deposited in a fluvial-lacustrine to palustrine environment; followed by layers of rhyolithic lavas and volcanoclastites with silicified plant trunks. Most of the analysed samples yielded a profusion of pollen and spores in a very good state of preservation. Three associations were distinguished. The first one comprises mostly radial and bilateral monosaccate pollen grains and very few spores. This association is characterized by the presence of pollen grains of the genera Crucisaccites, Luberisaccites, Gondwanopollis and Lueckisporites, together with very abundant Potonieisporites and subordinate Florinites. The second association comprises mostly pollen grains of the genus Potonieisporites, represented by many species, together with Limitisporites, Costapollenites, Vittatina and others. Spores mainly represented by azonate trilete and monolete types are more frequent than in the previous association. These first two palynological associations reflect assemblages of meso-xerophilous plants growing in dryer environments, belonging to tropical and subtropical phytogeographic biomas. The third association, mainly composed of Sphenophyte spores, is autochthonous and corresponds to a swampy hygrophilous flora settled after the filling up of the basin. The age inferred by means of sporomorphs is early Asselian which is in good agreement with the mean radiometric age of the volcanic rocks obtained by the ‘SHRIMP’ and the lead-zircon evaporation methods (297 ± 5 Ma). The upper succession, is composed of grey to red sandstones and thin pelites deposited on an alluvial plain under very hot and humid climate; its Permian, post-Asselian age cannot be better constrained because of the scarcity of the fossil content.  相似文献   

11.
The Palaearctic flea fauna includes 921 species and 479 subspecies from 96 genera of 10 families. Of them, 858 species (94%) from 43 genera are endemic to the Palaearctic; they comprise 40% of the Palaearctic Hystrichopsyllidae, 24% of Ceratophyllidae, and 20% of Leptopsyllidae. Ranges of 581 species (63% of the Palaearctic fauna) are situated within one province or subregion of the Palaearctic. Species with ranges including a part of Asia (592) comprise 87% of the total fauna; 72% of the species (517) are endemic to the Palaearctic. The largest centers of taxonomic diversity of Palaearctic fleas are situated in the East Asian, Central Asian, and Turano-Iranian Subregions: 320 species of fleas (214 of them endemic) from 59 genera (8 endemic) are known from the East Asian Subregion; 270 species (over 120 endemic) from 54 genera (5 endemic) are distributed in the Central Asian Subregion. The Turano-Iranian fauna comprises 213 species (103 endemic) from 47 genera (3 endemic); about 160 species occur in the Turanian Subprovince closest to the Russian borders, one-third of them (52 species, or 33%) are endemic; 69 species more are endemic to the entire Asian part of the Palaearctic. Extra-Asian and extra-Siberian ranges are known in 190 flea species. In the western Palaearctic, 76 species are endemic to the European Province, and 57 species, to the Mediterranean Province; 36 species have Euro-Mediterranean distribution. The fauna of the Saharo-Arabian Subregion comprises 30 species (12 endemic), 6 species have ranges of the Mediterranean-Saharo-Arabian type. Scenarios of the origin of the Siphonaptera at the Triassic-Jurassic boundary are hypothesized. Formation of the Palaearctic flea fauna was mostly supported by the Asian-Indo-Malayan and East Asian-Western American palaeofaunal centers of taxonomic diversity. The long history of faunal exchange between the east Palaearctic and the west Nearctic is manifested by the distribution of the parasites of rodents and insectivores, fleas of the genera Stenoponia, Rhadinopsylla, Nearctopsylla, and Catallagia, belonging to several subfamilies of the Hystrichopsyllidae, as well as members of a number of other flea families. A great number of endemic species in the genera Palaeopsylla and Ctenophthalmus (Hystrichopsyllidae), both in the European and Asian parts of the Palaearctic, can be explained by the junction of the European and Asian continental platforms in the late Cretaceous and their subsequent isolation during the Paleocene. A considerable contribution to the flea fauna in the Russian territory was made by the East Asian-Nearctic center of taxonomic diversity, with a smaller role of the European palaeofauna. Immigration of species of the family Pulicidae from the Afrotropical Region is restricted to the southern territories of Russia.  相似文献   

12.
Due to the recrudescence of cercarial dermatitis in the world, larval Schistosomatidae have been researched during 20 months in gastropods of stagnant fresh waters in a wetland. Brevifurcate ocellate cercariae have been detected after crushing in a species of Physidae, Aplexa hypnorum, with a prevalence of 6.52%. Up to now, this species had never been found infected by larval trematodes. Lymnaeidae, Planorbidae and other Physidae didn't harbour schistosomatids. Cercariae of A. hypnorum present furcal fin-folds and the length of the tail stem is inferior to that of the body. Only cercariae of Heterobilharzia americana, Schistosomatidae of Carnivora in America, have also these two features. This species, not described in Physidae, is an agent of the human cercarial dermatitis. Schistosomatid cercariae in american species of Physidae have been compared with that of A. hypnorum. Brevifurcate ocellate cercariae of A. hypnorum, possible agent of the cercarial dematitis, probably belong to a new species with unknown genus.  相似文献   

13.
鄂西南三个自然保护区蚁科昆虫的区系调查   总被引:1,自引:0,他引:1  
王维 《昆虫知识》2007,44(2):267-270
星斗山自然保护区、木林子自然保护区和坪坝营自然保护区地处湖北省西南山区,地形地貌复杂,属大陆性中亚热带季风湿润气候,昆虫资源十分丰富,作者首次报道这3个自然保护区蚂蚁的种类和分布。结果表明3个自然保护区共有蚂蚁53种,隶属于5亚科,22属。在区系组成上,东洋界种类25种,占全部种类的47.1%,东洋界和古北界均有分布的种类22种,占41.5%,古北种和特有种各有3种,分别占5.6%。说明3个自然保护区的蚂蚁以东洋界为主。并分析了3个自然保护区蚂蚁的分布特征。  相似文献   

14.
Uwe Kallweit 《ZooKeys》2013,(269):11-32
The distribution of Acomopterella species in the Palaearctic region has been re-examined in this study, using recently collected material. The European species was found to be distributed in the eastern Palaearctic as well. A second Palaearctic species from Honshu (Japan) is herein described. The morphology of adult specimens was studied by light microscopy and scanning electron microscopy. The shape of functional specialized setae on mid tibiae in Acomopterella and seven further fungus gnat genera is described and the suitability of this character for systematic studies is discussed. Details of a “hind tibial organ” are described.The position of Acomopterella in the tribe Gnoristini is briefly discussed. Acomopterella is found to be more closely related to Speolepta Edwards, 1925, than to any other recent genus.  相似文献   

15.
Habitat persistence should influence dispersal ability, selecting for stronger dispersal in habitats of lower temporal stability. As standing (lentic) freshwater habitats are on average less persistent over time than running (lotic) habitats, lentic species should show higher dispersal abilities than lotic species. Assuming that climate is an important determinant of species distributions, we hypothesize that lentic species should have distributions that are closer to equilibrium with current climate, and should more rapidly track climatic changes. We tested these hypotheses using datasets from 1988 and 2006 containing all European dragon- and damselfly species. Bioclimatic envelope models showed that lentic species were closer to climatic equilibrium than lotic species. Furthermore, the models over-predicted lotic species ranges more strongly than lentic species ranges, indicating that lentic species track climatic changes more rapidly than lotic species. These results are consistent with the proposed hypothesis that habitat persistence affects the evolution of dispersal.  相似文献   

16.
Food selection by freshwater snails in the Gezira irrigation canals,Sudan   总被引:1,自引:1,他引:0  
Henry Madsen 《Hydrobiologia》1992,228(3):203-217
Stomach content analysis was carried out on samples of the freshwater snail species Biomphalaria pfeifferi, Bulinus truncatus, Bulinus forskalii (Pulmonata, Planorbidae), Lymnaea natalensis (Pulmonata, Lymnaeidae), Melanoides tuberculata, Cleopatra bulimoides (Prosobranchia, Thiaridae) and Lanistes carinatus (Prosobranchia, Ampullariidae) from different irrigation canals in Sudan. In order to evaluate overlap in diet selection among these species, sites with two or more of the above-mentioned species present were selected. For some species food choice was examined in relation to size groupings. In addition, samples of Marisa cornuarietis (Prosobranchia, Ampullariidae) from small ponds in Sudan, samples of Biomphalaria pfeifferi and Helisoma duryi (Pulmonata, Planorbidae) from drainage canals in an irrigation scheme in northern Tanzania, and samples of H. duryi from fish ponds in the coastal area of Kenya were also analysed. The results indicate a great similarity in the food choice of these species, especially among the pulmonate species. All species feed on fine detritus, epiphytic algae and decaying macrophytes. No fresh fragments of aquatic macrophytes were found and animal remains were found only on a few occasions. However, the stomach contents of the ampullarid species were characterized by large fragments of dead macrophyte tissue, while the composition of the finer particles showed a great resemblance to that of the pulmonate species. The diet of the thiarid species is essentially the same as that of the pulmonate species, although in one site Cleopatra bulimoides showed a greater preference for green algae. Apart from the avoidance of blue-green algae, there was little evidence of selection of certain algal components of the Aufwuchs for the pulmonate species. Detritus constitutes the major component of the stomach content of all these snail species.  相似文献   

17.
A gelatin film procedure was used to localize proteolytic activity in the lumen of the intestinal ceca of Leucochloridiomorpha constantiae (Trematoda) adults. Slides were coated with a 7·5% gelatin solution and then fixed in 10% neutral buffered formalin (NBF). Cryostat sections of isolated worms or those attached to the bursa of Fabricius of the domestic chick were affixed to the gelatin film. Experimental and control slides were incubated in a humid chamber for 30 min at 37·5 and 4°C, respectively. Slides were again fixed in NBF, and then stained for protein with mercuric bromphenol blue (MBB). In experimental slides, the lumen of the intestinal ceca was lysed and did not stain, whereas worm and host tissue and the gelatin were protein-positive. Control sections stained uniformly positive for protein. In this procedure tissue is retained on the slide and proteolytic activity can be correlated with a tissue site on the same slide.  相似文献   

18.
Late Miocene brackish ostracods and molluscs collected in three Italian basins show noticeable differences in their taxonomic composition, despite their capability of dispersing across wide geographic areas. In the Venetian-Friulian Basin (northern Italy), the upper Tortonian sediments contain oligotypic ostracod assemblages including Hemicyprideis dacica dacica, Hemicytheria pejinovicensis, and Loxoconcha cf. L. josephi and few gastropods referable to Planorbidae and Stenothyroides, which are typical of the central Paratethys. In central Italy, the brackish ostracods and molluscs recovered from upper Tortonian-lower Messinian deposits from four Tuscan basins (Volterra-Radicondoli, Velona, Baccinello-Cinigiano, and Valdelsa) display high affinity at a generic level but strong endemicity at a specific level. At Cessaniti (southern Italy), the upper Tortonian unit contains oligotypic brackish ostracods and molluscs: Mediocytherideis (Sylvestra) posterobursa, Cyprideis ruggierii, Loxoconcha cf. L. biformata, and Zonocypris membranae quadricella characterise the ostracod fauna, while Granulolabium bicinctum and Hydrobia frauenfeldi are the dominant molluscs. The recovered ostracods have a strong affinity with brackish species from central and eastern Palaeo-Mediterranean areas, whereas the molluscs present a Paratethyan origin. Despite the fact that the basins are all brackish and partly coeval, the systematics of these assemblages highlights the absence of common species among the three studied areas. Geochemical analyses (stable isotopes and trace elements) are performed on ostracods, and 87Sr/86Sr ratios are established in molluscs and echinoids. The results suggest brackish environments with different compositions and origins of solutes in the three different areas. The Tuscan basins are characterised by brackish waters, with NaCl-enriched waters coming from aquifers of Triassic evaporite bedrock. The brackish deposits of the Venetian-Friulian Basin and Cessaniti are true marginal marine environments, although the northern basin may have been influenced by both the Paratethyan Sava Basin and the northern portion of the Palaeo-Mediterranean water bodies.  相似文献   

19.

Aim

To project the impact of climate change on dragonfly and damselfly diversity in West and Central Asia.

Location

West and Central Asia.

Time period

1900–2020 data used to predict distributions in 2070 and 2100.

Taxon studied

Odonata.

Methods

Based on 149,001 records, distribution models were created for 159 species using MaxEnt. Environmental variables consisted of climate variables taken from BIOCLIM, river data and soil data. The future climate data were obtained from CHELSA from CMIP6 climate models. The same variables were collected for three scenarios (SSP1-2.6, SSP3-7.0 and SSP5-8.5) of shared socioeconomic pathways for the years 2050–2070 and 2080–2100. For each scenario and period, diversity maps were prepared for six species groups: all species, Lentic, Lotic, Oriental, Afrotropical and Palaearctic species.

Results

Strong declines in diversity are expected in western Turkey, the Levant and Azerbaijan, and to a lesser extent in parts of Iran and southern Central Asia. An increase is expected in eastern Turkey and at higher elevations in Central Asia with a limited increase throughout the Arabian Peninsula. In contrast to expectations, a decrease in areas with <15 species was found. Faunal composition is predicted to show strong shifts, with Palaearctic species declining and Oriental and Afrotropical species increasing. No clear difference between the trend of lentic and lotic species is found, although there are clear spatial differences in trend between these groups.

Main Conclusions

Climate change will result in strong changes in diversity and distribution of dragonflies and damselflies in West and Central Asia with regional declines and increases. None of the species are predicted to go extinct based on the impact of climate change only, however, the combined impact of climate change and anthropogenic forces is likely to push some of the species to near extinction by 2100.  相似文献   

20.
A total of 176 species of butterflies have been found in West Altai. Their distribution ranges, phenology, biological preferences, and taxonomic structure are analyzed. Numerous Siberian butterfly species from the genera Erebia, Oeneis, Clossiana, Boeberia, and Colias have been found in West Altai which may be accounted for its westernmost position in the mountain system of southern Siberia and very humid climate. At the same time, many western Palaearctic as well as few Middle Asian butterflies have been discovered in West Altai for the first time. West Altai is the region where pairs of sister species which diverged in the Western and Eastern Palaearctic can be found in secondary contact. In this study, a zone of stable secondary sympatry of Melitaea didyma (western element) and M. latonigena (eastern element) as well as that of Maculinea arion (western element) and M. cyanecula (eastern element) has been found. These findings provide the first strong evidence for the distinctness of the species in these sister pairs.  相似文献   

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