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1.
Based on ultrastructural study and molecular analysis, a new genus, Ovipleistophora, is established for Pleistophora mirandellae-like microsporidia from roach and ruff oocytes. Unlike Pleistophora, Ovipleistophora has a thick additional envelope around the meront. This envelope breaks open to release the cells into the host cell cytoplasm. The cells, becoming multinuclear sporogonic plasmodia, already have a surface coat that transforms into the sporont wall and eventually into the sporophorous vesicle wall. The surface coat and its transformation differ from those of Pleistophora, but bear some resemblance to those of Trachipleistophora. In Trachipleistophora the sporonts, however, do not form plasmodia, as they do in Ovipleistophora and Pleistophora. Small subunit ribosomal DNA analysis supports the establishment of the new genus and assignment of P. mirandellae from 2 different fish hosts to the same species. The same small subunit ribosomal DNA analysis lends support for transferring P. ovariae into the genus Ovipleistophora.  相似文献   

2.
Unilatus gen. n., a unique neotropical genus of Monogenea   总被引:1,自引:0,他引:1  
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3.
The earliest known ovules in the Late Devonian (Famennian) are borne terminally on fertile branches and are typically enclosed in a cupule. Among these ovules are some that have terete integumentary lobes with little or no fusion. Here, we report a new taxon, Latisemenia longshania, from the Famennian of South China, which bears cupulate ovules that are terminal as well as opposite on the fertile axis. Each ovule has four broad integumentary lobes, which are extensively fused to each other and also to the nucellus. The cupule is uniovulate, and the five flattened cupule segments of each terminal ovule are elongate cuneate and shorter than the ovule. Associated but not attached pinnules are laminate and Sphenopteris-like, with an entire or lobate margin. Latisemenia is the earliest known plant with ovules borne on the side of the fertile axis and may foreshadow the diverse ovule arrangements found among younger seed plant lineages that emerge in the Carboniferous. Following the telome theory, Latisemenia demonstrates derived features in both ovules and cupules, and the shape and fusion of integumentary lobes suggest effective pollination and protection to the nucellus. Along with other recent discoveries from China, Latisemenia extends the palaeogeographic range of the earliest seed plants.  相似文献   

4.
A new genus Moreiba is described for Strophosoma canariense Franz, 1995 (type species) and placed in Laparocerini. It differs from Laparocerus Schoenherr, 1834 by the small size, the strongly transverse rostrum, the dense longitudinal strigosity on head and rostrum, the body covered by dense, adpressed scales and short, semierect subspatulate to parallel setae, the slender antennae with bisinuate scape and short oval club, the granulate pronotum and all tibiae lacking a mucro in both sexes. Moreiba canariensis (Franz, 1995), comb. n., is the only described species, distributed in El Hierro and Gran Canaria. The tribal placement of the genera Aphyonotus Faust, 1895, Asmaratrox Heller, 1909, Straticus Pascoe, 1886 and Cyrtozemia Pascoe, 1872 is discussed.  相似文献   

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6.
Based on a fine structural study, a new genus, Kabataia gen. n., is proposed for Microsporidium arthuri Lom, Dyková and Shaharom, 1990. It develops in trunk muscles of a South-East Asian freshwater fish, Pangasius sutchi. The genus has nuclei isolated throughout the cycle, merogony stages are multinucleate, sporogony proceeds in 2 steps: multinucleate sporont segments into sporoblast mother cells which produce 2 sporoblasts. Sporoblasts and early spores are characterized by a dense globule at the site of the posterior vacuole. Mature spores are of a rather variable shape. Their exospore is raised into small, irregular fields. The polaroplast is relatively small and its posterior part consists of flat vesicles with dense contents. The polar tube makes a small number (4 to 6) of turns. A congeneric species is Kabataia seriolae (Egusa, 1982) comb. nov. from cultured marine yellowtails Seriola quinqueradiata. Kabataia inflicts heavy damage on muscle tissue. The sarcoplasm within which Kabataia develops is reduced to an amorphous mass with tubule-like fibrils, microfibrils and small vesicles.  相似文献   

7.
A new genus and new species of mantidflies, Doratomantispa burmanica n. gen., n. sp. (Neuroptera: Mantispidae), is described from Burmese amber. Diagnostic characters of the new genus are small body size, trichosors present around entire wing margin except basally, protarsus 5-segmented with paired, simple claws but no aroleum, profemur bearing six cuticular spines, inner surface of protibia with row of peg-like protrusions, Sc meets R1 in region of pterostigma, costal space greatly narrows toward wing apex, with 16 veinlets in costal space on front wing while costal veinlets on hind wing are replaced by trichosors and CuP absent in hind wing. The abdomen of the mantidfly is filled with large spheres resulting from a possible rickettsial infection. Phoretic heterostigmatid mites are adjacent to the wings of the fossil.  相似文献   

8.
From marine mud flats a very thin, comma- or spiral-shaped bacterium was isolated. The new organism was an obligately chemolithotrophic sulfur bacterium. Its physiology was found to be essentially similar to that ofThiobacillus thioparus. Because of the spirillum-like appearance it was proposed to classify this bacterium into a new genusThiomicrospira, with the species nameTms. pelophila. Tms. pelophila and a marineT. thioparus, which was isolated from the same mud, occupy different niches in this habitat.Tms. pelophila has a remarkable sulfide-tolerance as compared withT. thioparus. This property could be used for the specific enrichment ofTms. pelophila. The organism was also readily isolated in pure culture by filtering mud suspensions through a 0.22 Μm membrane filter.  相似文献   

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10.
A new genus, Pseudocatamachilis gen.n. is established on the basis of a thorough study of many specimens male and female of Catamachilis torquata (Nav#aAs, 1905). All type material was lost during the Spanish civil war (1936-39). A neotype is designated and the species redescribed. Genus Pseudocatamachilis is related to Catamachilis Silvestri and Promesomachilis Silvestri, but distinguished from these genera by the type of ovipositor and the presence of two pairs of parameres, among other characteristics given in the text.  相似文献   

11.
Rélová M 《Mycologia》2007,99(5):723-732
The new genus Barbatosphaeria is described for a perithecial ascomycete known as Calosphaeria barbirostris occurring on decayed wood of deciduous trees under the periderm. The fungus produces nonstromatic perithecia with hyaline, 1-septate ascospores formed in unitunicate, nonamyloid asci. Anamorphs produced in vitro belong to Sporothrix and Ramichloridium with holoblastic-denticulate conidiogenesis; conidiophores of the two types were formed in succession during the development of the colony. Phylogenetic analyses of nuLSU rDNA sequences indicate that this fungus is distinct from morphologically similar Lentomitella, tentatively placed in the Trichosphaeriales. It groups with freshwater Aquaticola and Cataractispora and terrestrial Cryptadelphia in maximum parsimony analysis; the same grouping but without Cryptadelphia was inferred from Bayesian analysis. Cultivation, morphology and phylogenetic studies of the nuLSU rDNA support the erection of a new genus for C. barbirostris.  相似文献   

12.
A new genus, Helgoeca gen. nov., has been designated to accommodate a nudiform loricate choanoflagellate (American Type Culture Collection strain ATCC 50073) that was incorrectly attributed to the tectiform genus Acanthoecopsis (=Acanthocorbis). The first indication that this species might be nudiform came from a four-gene phylogeny of the choanoflagellates which recovered ATCC 50073 within a strongly supported monophyletic clade comprising two other nudiform taxa. Fortunately an isolate of the species in question was available from the ATCC and when observed in rapidly growing culture it was immediately apparent that this species divided with the production of 'naked' motile cells; a typically nudiform character. The beaker-shaped lorica of this species consists of an outer layer of approximately 11 longitudinal costae, which terminate anteriorly as spines, and an equal or larger number of helical costae, with a left-handed conformation, each of which terminates anteriorly adjacent to the base of a spine. The pattern of costae in this species is indistinguishable from that of Acanthocorbis nana Thomsen and for this reason A. nana has been transferred to the new genus Helgoeca gen. nov., as the type species.  相似文献   

13.
14.
Abstract

A new genus and species of heteronemertean, Praealbonemertes whangateaunienses n. gen. and n. sp., is described and illustrated. The species is characterised by inter alia a cephalic lacuna with strands of longitudinal muscle fibres, a proboscis with three muscle layers, and a well-developed muscle plate dorsal to the foregut and anterior intestine. The material was collected in New Zealand.  相似文献   

15.
A new Oriental genus Hecabolomorpha n. gen. with the type species H. asiatica n. sp. is described and illustrated from India and Central China. The position of this genus in the tribe Hecabolini and its relations with hecaboline genera are discussed.  相似文献   

16.
A sphenopsid from the Upper Devonian (Famennian) Xiejingsi Formation, south-western Hubei Province, China, previously named as various species in Sphenophyllum , Hamatophyton , Bowmanites and Sphenophyllostachys , is now reinvestigated and assigned to a new taxon, Rotafolia songziensis gen. et comb. nov. Its ribbed axes are anisotomous and possess slightly expanded nodes. Lateral axes are inserted at nodes on main axes. Whorls of much divided vegetative leaves are attached at nearly right angles to nodes of basal axes, and at acute angles to nodes of terminal axes. There are six leaves per whorl. The terminal strobilus includes a central axis and verticils of fertile units. Each fertile unit consists of a bract and numerous sporangia. The margin of the elongate-cuneate bract bears a distal and many lateral elongate segments. Clusters of elongate sporangia are abaxially attached to the base of the bract at the same level. The axis has an actinostele, composed of a three-ribbed, exarch primary xylem and radial secondary xylem. Although Rotafolia songziensis closely resembles Hamatophyton verticillatum in axis character, leaf morphology and primary xylem type, they are quite different in strobilar structure. Taxonomically, Rotafolia is placed in the order Sphenophyllales by three well-defined characters: 1) whorled appendages; 2) ribbed protosteles; 3) exarch primary xylem maturation.  © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society , 2005, 148 , 21–37.  相似文献   

17.
Two new species of heterolobosean amoebae from anoxic environments, Monopylocystis visvesvarai and Sawyeria marylandensis, are described on the basis of light microscopy, electron microscopy, and their phylogenetic affiliation based on analyses of nuclear small-subunit ribosomal RNA gene sequences. Both species lack mitochondria but have organelles provisionally interpreted as hydrogenosomes, and neither can tolerate aerobic conditions. As their conditions of culture do not exclude all oxygen, they may be microaerophiles rather than strict anaerobes. Both species have unusual nucleolar morphologies. Monopylocystis visvesvarai, from a marine sediment, has nucleolar material distributed around the nuclear periphery. It is the first non-aerobic heterolobosean protist for which a cyst is known; the cyst is unmineralized and unornamented except for a single, raised, plugged pore. Sawyeria marylandensis, from an iron-rich freshwater stream, has nucleolar material distributed in one or two parietal masses, which persist during mitosis. In phylogenetic analyses of small-subunit rRNA gene sequences, Monopylocystis visvesvarai, Sawyeria marylandensis and Psalteriomonas lanterna converge to form a single clade of non-aerobic (anaerobic/microaerophilic) heteroloboseans.  相似文献   

18.
The generic diagnosis of the male imago of a new genus of the subfamily Orthocladiinae (Chironomidae), Saetheriella is given. The genus is characterized by protruding, hairy eyes; antenna with straight, apical seta; antepronotum reduced; squama without setae; Cu1 distinctly downcurved; and anal point short, triangular, covered with microtrichia and with two strong, lateral setae. The genus is close to Gynnidocladius Sublette & Wirth, Unniella Sæther and Parakiefferiella Thienemann. The distribution of the genera shows evidence of a Gondwanian connection. The male imago of the only included species S. amplicristata sp. n. is described.  相似文献   

19.
20.
Seven marine gymnamoebae were isolated from different environments of seawater, slush (pack ice meltwater), and sediment in the Ross Sea area of Antarctica. All amoebae were isolated and maintained at temperatures below 4 degrees C. Growth, rate of locomotion, and general morphology were observed at an environmentally appropriate temperature (1 degrees C) and at room temperature (approximately 25 degrees C). Molecular (srDNA sequences) and microscopical techniques were used to identify the gymnamoebae and establish their phylogenetic affinities. Three isolates (S-131-2, SL-200, and W4-3) were assigned to a psychrophilic subspecies of Neoparamoeba aestuarina, N. aestuarina antarctica n. subsp., one isolate (S-205) was assigned to a new species of Platyamoeba, P. oblongata n. sp., two isolates (W51C#4 & W51C#5) were also assigned to a new species of Platyamoeba, P. contorta n. sp., and one isolate (S-241) was a novel psychrophilic gymnamoeba Vermistella antarctica n. gen. n. sp. Molecular and morphological results revealed that V. antarctica was not related to any described family of gymnamoebae. Strains S-205, W51C#4, and W51C#5 were capable of locomotion at room temperature, while strains SL-200, S-131-2, W4-3, and S-241 exhibited locomotion only below approximately 10 degrees C. Our results imply that the Antarctic environment is host both to cosmopolitan gymnamoebae that have acquired adaptations for existence at low environmental temperature and to apparently novel psychrophilic amoebae described here for the first time.  相似文献   

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