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1.
    
The taxonomic validity, present distribution, and specific threats to the existence of the freshwater sponge, Anheteromeyenia biceps (Lindenschmidt, 1950) were investigated. The species, reported only from the type locality, Bessey Creek and Maple River, two streams flowing into Douglas Lake, Michigan, is relegated to synonomy with Ephydatia mülleri. Habitat data from Bessey Creek and Maple River, particularly physicochemical data, greatly extend the known environmental parameters of Heteromeyenia tubisperma and Ephydatia mülleri.  相似文献   

2.
Taxonomy and ecology of methanogens   总被引:5,自引:0,他引:5  
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3.
    
The taxonomic status of Ephydatia subtilis (Weltner) remains undetermined. Despite extensive collecting in the type locality, Lake Kissimmee, Florida, the species was not found. Stratospongilla penneyi sp. nov. is described utilizing spicular diagnosis, cytochemistry, and scanning electron microscopy. Physicochemical data from the type locality are presented and specific threats to the existence of the species are determined.  相似文献   

4.
The taxonomic validity, present distribution, and specific threats to the existence of the freshwater sponge,Spongilla sponginosa Penney were investigated. This species, reported only from the type locality, Week's Pond, Sumter County, South Carolina, has apparently been extirpated due to highly acidic pH levels in the pond water. Examination of holotype materials indicate some question of the validity of S. sponginosa as a distinct species.  相似文献   

5.
    
The taxonomic status, present distribution and specific threats to the existence of the environmentally restricted freshwater sponge, Spongilla heterosclerifera Smith 1918 were investigated. This species, collected only from Oneida Lake, New York, has not colonized other habitats and continues to exhibit typical diagnostic characteristics, thus qualifying as a valid environmentally restricted species. Although the sponge presently colonizes two sites in the lake, both near the northwestern shore, the total absence of sponge fauna from other lake regions near more heavily populated areas of this species. Physicochemical data from Oneida Lake greatly extend the known environmental parameters of Spongilla heterosclerifera.  相似文献   

6.
柏科分类和分布:亚科,族和属   总被引:4,自引:0,他引:4  
柏科Cupressaceae和杉科Taxodiaceae有许多相似之处,近年来不少分类学家主张把两科合并成广义的柏科。原杉科中的金松属Sciadopitys与两科其他属的差异较大,被提升为单种科Sciadopity-aceae。本文根据球果可育种鳞的位置把柏科(狭义)分为2亚科,即上部种鳞不可育的柏木亚科Cupres-soideae和上部种鳞可育的澳洲柏亚科Callitroideae。综合其他形态学和解剖学证据,柏木亚科又分4族,即柏木族Cupresseae(包括:柏术属Cupressus、杂交柏属×Cupressocyparis、扁柏属Chamaecyparis和福建柏属Fokeinia)、侧柏族Thujopsideae(包括:崖柏属Thuja、罗汉柏属Thujopsis和侧柏属Platycladus)、圆柏族Junipereae(包括:圆柏属Juniperus和海参威柏属Microbiota)以及香漆柏族Tetraclineae(包括:翠柏属Calocedrus和香漆柏属Tetraclinis)。澳洲柏亚科又分3族,即澳洲柏族Actinostrobeae(包括:西澳柏属Actinostuobus、澳洲柏属Callitris、智利柏属Fitzroya和杉叶柏属Neocallitropsis)、南非柏族Widdring-toneae(包括:白智利柏属Pilgerodendron、塔斯曼柏属Diselma和南非柏属Widdringtonia)以及甜柏族Libocedreae(包括:甜柏属Libocedrus、巴布亚柏属Papuacedrus和南美柏属Austrocedrus)。柏科21个属的地理分布可划分为5种类型,即:(  相似文献   

7.
The study of winter-active small mammals beneath the snowpack has proved challenging for researchers because of the relative inaccessibility. We present a technique using hair tubes that permits the detection of small mammals active in the subnivean space. Hair tubes are cylindrical or funnel-shaped structures containing suitable bait and an adhesive surface that harvests hairs from small mammals as they attempt to reach the bait. Hair tubes eliminate many of the difficulties often associated with live trapping and permit the expansion of systematic sampling to larger scales than allowed by conventional live-trapping methods. The technique was used successfully to detect five small mammal species in the subnivean space in Kosciuszko National Park (KNP) in southeastern Australia. These included the common bush-rat, Rattus fuscipes; the dusky and agile antechinus, Antechinus swainsonii and A. agilis; the broad-toothed rat, Mastacomys fuscus; and the mountain pygmy possum, Burramys parvus. Although hair tubes have a number of limitations, such as not providing a measure of abundance or allowing the identification of individual animals, we believe that these limitations are balanced by the fact that the technique can be used at any spatial scale. Hair tubes are particularly suited to studies of animal distribution at the landscape-scale, because many hair tubes can be deployed and dispersed over large areas, and monitored on a regular basis by a small team of researchers. The technique also makes use of readily available, low-cost materials and could be easily adapted to a range of conditions and different target species.  相似文献   

8.
对中国四齿藓科的分类及分布进行了全面研究。据陈邦杰等前人报道,本科在中国分布仅1属1种。现经作者们搜集到的236份中国四齿藓科标本(原均被鉴定为四齿藓TetraphispelucidaHedw.),重新解剖观察后鉴定,发现除原有之广布种四齿藓外,尚有此次新发现的中国新分布种:疣柄四齿藓TetraphisgeniculataGirg,另有傅星及高谦等在川西发现新分布原丝藓Tetrodontiumbrownianum(Dicks)Schwaegr.,以及H.Vil和曹同在吉林发现的无助原丝藓Tetrodontiumrepandum(FunckexSturm)Schwaegr.,故本科在中国分布增至2属4种,本文对此4种在中国及世界分布均进行了讨论。  相似文献   

9.
    
Cupressaceae and Taxodiaceae have recently been merged under the earlier name Cupressaceae s.I. by many authors, as the two families are similar in a number of morpho logical characters. Sciadopitys S. et Z., which has often been treated as a morphologically isolated member of the Taxodiaceae, has recently been considered as a monotypic family, Sciadopityaceae. The Cupressaceae s.s. may be reorganized into two subfamilies. The Cupressoideae is composed of genera with the uppermost cone-scales infertile and can be divided into four tribes: Cnpresseae, including Cupressus, X Cupressocyparis, Charnaecyparis and Fokeinia;Thujopsideae, including Thuja, Thujopsis and Platycladusl Junipereae, including Juniperus and Microbiota; and Tetraclineae, including Calocedrus and Tetraclinis.The Callitroideae is composed of genera with the uppermost cone-scales fertile and can be divided into three tribes: Actinostrobeae, including Actinostrobus, Callitris, Fitzroya andNeocallitropsis; Widdringtoneae, including Pilgerodendron, Diselma and Widdringtonia ;Libocedreae, including Libocedrus, Papuacedrus and Austrocedrus. Five geographical distribution patterns are recognized in the 21 genera of Cupressaceae. (a) One genus, X Cupressocyparis, is a natural hybrid derived from selections in England; (b) Two genera, Cupressus and Juniperus, are distributed in Africa, Europe, Asia and North America; (c)Three genera, Thuja, Chamaecyparis, and Calocedrus, are disjnnctly distributed in Eastem Asia and North America; (d) Five genera, Actinostrobus, Callitris, Libocedrus,Papuacedrus and Widdringtonia, have limited distribution; and (e) The other 10 genera,which are monotypic, are restricted to narrow areas except Plotycladus. Three centers ofgenera diversity are identified in the Cupressaceae, i. e Eastern Asia with nine genera, southwestern North America with five genera, and Australia and its adjacent islands in the east with six genera, including New Zealand,. Tasmania, New Caledonia, and New Guinea.Other important areas are western Mediterranean with three genera and Chile and Argentinawith three genera.  相似文献   

10.
    
The morphological characters in the genus Orobanche were evaluated from thetaxonomic point of view. The author finds that the plants of this genus are relatively similarto each other in respect to characters of vegetative organs, fruits and seeds. But the differencesin the floral structures can be served as a basis for delimitating infrageneric taxa. The seedcoat of 18 species and pollen grains of 6 species were also examined under scanning electronmicroscope (SEM). They seem to have little significance for distinguishing species. The result supports G. Beck’s (1930) division of the genus Orobanche into 4 sections, ofwhich 2 occur in China, based on the characters of the inflorescence, bracteoles and calyx.The author considers that some characters, such as anther hairy or not, upper lip of corollaentire or not, lower lip longer or shorter than the upper one, the state of corolla-tube inflec tion and the hair type of filaments and plants, are important in distinguishing Chinese species. A key to the species of Orobanche in China is given. This genus consists of about 100 species, and is mostly confined to Eurasia, with over 60 species found in Caucasus and Middle Asia of USSR, where may be the mordern distribu tional centre. Orobanche L. in China is represented by 23 species, 3 varieties and l forma. As shown in Table 1, most species (12 species) are found in Xinjiang, which clearly shows a close floristic relationship between this region and Middle Asia of USSR. 6 species are endemic to China, of which 4 are confined to the Hengduan Mountains (Yangtze-Mekong-Salwin divide). The relationships between this genus and related ones of Orobanchaceae are also discussed. The author holds the following opinions: the genus Phelypaea Desf. should be considered as a member of Orobanche L. Sect. Gymnocaulis G. Beck, the monotypic genus, Necranthus A. Gilli endemic to Turkey, is allied with Orobanche L. Sect. Orobanche, the monotypic genus, Platypholis Maxim, endemic to Bonin Is. of Japan, is far from Orobanche L. in relation and should be regarded as a separate genus. The 11 OTU’s, including all the sections of Orobanche L. and 7 genera of Orobanchaceae, and 15 morphological characters were used in the numerical taxonomic treatment to test the above-mentioned suggestions. After standardization of characters, the correlation matrices were computerized. The correlation matrices were made to test the various clustering methods. At last the UPGMA clustering method was chosen and its result is shown in a phenogram. The result of numerical analysis is basically in accordance with the suggestions.  相似文献   

11.
    
《Fungal biology》2020,124(6):601-611
We recovered 195 fungal isolates from the sediments of different lakes in the Antarctic Peninsula, which were screened to detect bioactive compounds. Forty-two taxa belonging to the phyla Ascomycota, Basidiomycota, and Mortierellomycota were identified. Thelebolus globosus, Antarctomyces psychrotrophicus, Pseudogymnoascus verrucosus, Vishniacozyma victoriae, and Phenoliferia sp. were found to be the most prevalent. The fungal assemblages showed high diversity and richness, but low dominance values. However, the diversity indices and fungal distribution ranged according to the different lake sediments. Sixty fungal extracts displayed at least one biological activity against the evaluated targets. Among them, Pseudogymnoascus destructans showed selective trypanocidal activity, Cladosporium sp. 1 and Trichoderma polysporum showed antifungal activity, and Pseudogymnoascus appendiculatus and Helotiales sp. showed high herbicidal activity. We detected a rich and diverse fungal community composed of cold cosmopolitan and psychrophilic endemic taxa recognized as decomposers, symbiotics, pathogens, and potential new species, in the sediments of Antarctic lakes. The dynamics and balance of this fungal community represents an interesting aquatic web model for further ecological and evolutionary studies under extreme conditions and potential climate changes in the regions. In addition, we detected fungal taxa and isolates able to produce bioactive compounds that may represent the source of prototype molecules for applications in medicine and agriculture.  相似文献   

12.
Manfred Kutscher 《Geobios》2003,36(2):179-194
The Toarcian sediments exposed at Sainte-Verge (Deux-Sèvres, France) are especially rich in echinoderm remains. The present paper describes and illustrates the ophiuroids. On the basis of lateral arm plates, 13 species are distinguished, including two new ones: Sinosura fasciata sp. nov. and Sinosura extensa sp. nov. Most of the recognized species have been recorded previously from the Late Toarcian and Aalenian in Germany and, to a lesser extent, from the late Early Jurassic of England and Switzerland. High similarities between the faunas of northwest Europe suggest a boreal provincialism of ophiuroids. The recognition of 13 species is comparable to the diversity known from other stratigraphic levels (Jurassic and Cretaceous) or in the richest stations of recent oceans. The species association of the Toarcian of Sainte-Verge, with two Ophiolepididae, one Ophiacanthidae, four Ophioleucidae, two Ophiodermatidae, two Ophiuridae, and one Hemieuryalidae may be compared with species associations of recent shelf, offshore environments. Such persistence of components of diversity and ecological affinities of species suggests strong evolutionary conservatism of the ophiuroids, after a rapid radiation during the earliest Jurassic. © 2002 Éditions scientifiques et médicales Elsevier SAS. All rights reserved.  相似文献   

13.
Complete, articulated starfish fossils are rare. However, more frequently encountered dissociated skeletal elements (ossicles) permit reliable taxonomic identification, making them a valuable data source for diversity estimates. Nearly 300 asteroid ossicles, collected from the middle Toarcian marls in western France can be assigned to five species. Four species and two genera are described: Comptoniaster vrinensis nov. sp. (Goniasteridae), Poncetaster crateri nov. gen. nov. sp. (Stauranderasteridae), Galbaster recurrans nov. gen. nov. sp. (Goniasteridae) and Pentasteria? liasica nov. sp. (Astropectinidae). The known diversity of Early Jurassic asteroids is increased from 12 to 16 species. These taxa illustrate the diversification of crown-group asteroids early in the Jurassic, following the Permo-Triassic crisis. They also reflect bias of the fossil record, and imply the existence of numerous ghost lineages in the evolutionary trees of extant groups. Variation in asteroid diversity across the “Seuil du Poitou” was driven by ecological constraints. The relative frequency (abundance of ossicles and diversity) of goniasterids and stauranderasterids increases in shallower environments. The Benthopectinidae, represented by Plesiastropecten hallovensis, occurred primarily from deep-shelf sediments. Similar ecological patterns are observed for more recent fossil and extant relatives, which further supports the idea of conservative evolution in post-Palaeozoic starfishes since the Early Jurassic.  相似文献   

14.
15.
Vegetation cover is known to act as an abiotic mediator influencing the structure of soil fauna communities in arid and semi-arid ecosystems. The aim of the current research was to determine the spatial dispersion of the soil free-living nematode community under the canopy of Cercidium praecox and Prosopis laevigata during the rainy season. These shrubs are the dominant plant associations in the western part of the Tehuacán-Cuicatlán Valley in Mexico. Soil samples were taken from each 10-cm depth between 0 and 50 cm in August 2004. Our results demonstrated that the abundance and structure of the soil free-living nematode communities in the study area were strongly dependent on plant effects, specified by limited factors such as soil moisture and organic matter availability. The greatest degree of abundance of soil-free-living nematodes (88%) was found in the upper (0–10 cm) soil layer. Plant parasites were the most abundant trophic group under the two plants (58 and 36% under Parkinsonia (Cercidium) praecox and Prosopis laevigata, respectively), whereas omnivore-predators were the most dominant (96%) in inter-plant spaces. The fungivore/bacterivore (F/B) ratio was found to be the most useful tool of the ecological indices tested in the present study, reflecting the vertical distribution of the free-living nematode communities beneath different plant species in the different soil layers. The soil free-living nematode communities and their vertical distribution were found to be affected by plant ecophysiological adaptation, soil moisture, and the interaction between them.  相似文献   

16.
17.
The aim of the present work was to determine phylogenetic relationships among Astraeus species and to support macroscopic and microscopic characters of Astraeus with analysis of the ITS rDNA region. Collections of Astraeus basidiomes were made from different geographical areas in Thailand and compared with existing collections made worldwide. The marriage of observations on morphological features, including basidiospore ornamentation and molecular data demonstrated the presence of several Astraeus species. Sequences for 41 Astraeus collections were compared and the phylogenetic analyses grouped Thai Astraeus collections into two distinct groups. One contained A. odoratus and an Asian species described herein as A. asiaticus. There are at least two additional species: A. pteridis, and one so far un-named from North America. Our results show that molecular data can be used in combination with traditional morphological characteristics to resolve taxonomic uncertainties in the genus Astraeus.  相似文献   

18.
    
This study focused on the taxonomy and diversity of the endophytic fungi associated with Vellozia gigantea, an endemic, ancient, and endangered plant species that occurs only in the rupestrian grasslands of Brazil. A total of 285 fungal isolates were recovered from leaves and roots of the V. gigantea, which were identified in 27 genera and 87 different taxa using molecular taxonomy methods. Xylaria berteri, Diaporthe sp. 1, Nigrospora oryzae, Muscodor sp. 1, Colletotrichum aeschynomene, and Trichoderma viride occurred in the highest frequency in both the leaf and root. Diaporthe was the most abundant genus, with 70 endophytic isolates recovered from the leaves and roots. Among all the taxa identified, 62 occurred as singlets, including those of the genera Clonostachys, Coccomyces, Crucellisporiopsis, Daldinia, Myxotrichum, Pallidocercospora, Pezicula, Peyronellaea, and Pseudocercospora. The diversity indices displayed high values, showing that V. gigantea shelters a diverse and rich mycobiota. Our results indicate that V. gigantea shelters in its tissues a highly diverse and cryptic mycobiota, including several rare species previously unreported as endophytes, but that are reported to have different ecological functions, which might be an important biological component contributing to the fitness of the plants living in the rupestrian grassland.  相似文献   

19.
20.
We report new records of Gnamptogenys caelata Kempf (1967) and Gnamptogenys minuta (Emery, 1896) from Brazil. We also describe Gnamptogenys piei n. sp. from Southeast Brazil. This distinctive new species is known only from a single worker found in leaf litter from montane forests of the Mantiqueira mountains in Itatiaia National Park, Rio de Janeiro State, Brazil. The specimen was collected at 1991 m above sea level, an infrequent altitude for minuta-group ants, usually more common at lower altitudes. The new species is imaged, compared with other minuta-group species, and an updated identification key for all known species of the minuta-group is included.  相似文献   

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