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1.
肉疣衣属地衣(子囊菌门)二新记录种   总被引:2,自引:1,他引:1  
赵遵田  贾泽峰 《菌物学报》2002,21(2):291-292
Thallus crustose, yellowish-gray, yellowish-white or cream-colored, covering areas of moss, thin to thick, sometimes very thick especially at the center, continuous, forming patch of coarse, irregular, granulose isidia, which connect into broad granular areas ; prothallus absent. Apothecia: sessile, 1.5~2.5mm in diameter; disks pale to light yellowish pink, lightly white pruinose, at first sunken and smooth, later with even, inner margin or ring adjacent to the disk, and a coarsely granulose o…  相似文献   

2.
2006年3月中旬浙江省乐清县岐蒲镇渔民在中国东海南部(靠近台湾北部)海域捕获一条体长4 560 mm的鲨鱼.经鉴定为大口鲨Megachasma pelagios Taylor,Compagno et Struhsaker,1983,为我国大陆沿海鲨鱼1新纪录种.  相似文献   

3.
南鳅属鱼类一新种及南鳅属评述   总被引:3,自引:0,他引:3  
陈毅峰 《动物学研究》1999,20(4):301-305
记述了南鳅属鱼类一新种--异颌南鳅Schistura heterognathos sp.nov.,用作新种描述的模式标本共7属,其中正模标本1属,体长80.0mm,编号8810240;副模标本6属,体长95.0-105.0mm,编号8810241、8810241、8810150 ̄8810153。1988年采自云南省勐腊县的那着和曼庄,属澜沧江下游支流南腊河。所有模式标本均保存于中国科学院水生生物研  相似文献   

4.
Pollen of 110 species from 18 genera in thePortulacaceae has been examined by light and scanning electron microscopy, and a representative number by transmission electron microscopy. Three basic pollen types were found: 3-colpate with thick tectum and foot layer with prominent unbranched columellae and an extremely thin endexine; pantoporate with thick tectum and foot layer with branched columellae enclosing pores and an endexine that is one to two layers thick; pantocolpate with thin tectum and foot layer with broad, short unbranched columellae and an inconspicuous endexine. All pollen types, however, have a spinulose and tubuliferous/punctate ektexine. Also, all the genera except three,Calandrinia H.B.K.,Montia L. andTalinum Adanson are stenopalynous. There is, however, no absolute correlation between pollen morphology and geographical distribution, although both the major centre of palynological diversity and the majority of all species with tricolpate grains occur in South America.  相似文献   

5.
Understanding the molecular mechanism of muscle contraction and its regulation has been greatly influenced and aided by studies of myofilament structure in invertebrate muscles. Invertebrates are easily obtained and cover a broad spectrum of species and functional specializations. The thick (myosin-containing) filaments from some invertebrates are especially stable and simple in structure and thus much more amenable to structural analysis than those of vertebrates. Comparative studies of invertebrate filaments by electron microscopy and image processing have provided important generalizations of muscle molecular structure and function. This article reviews methods for preparing thick and thin filaments from invertebrate muscle, for imaging filaments by electron microscopy, and for determining their three dimensional structure by image processing. It also highlights some of the key insights into filament function that have come from these studies.  相似文献   

6.
Lecanora compallens and L. sinuosa, two corticolous lichens, are described as species new to science on the basis of numerous collections. Lecanora compallens is a sorediate species, known only as sterile. It is probably common in Western Europe, but overlooked because it is very similar to L. expallens. Chemically, the new species is identical with L. strobilina, of which it may represent a sorediate counterpart. Lecanora sinuosa is a new species similar to L. chlarotera and so far only known from a limited area in the Netherlands and Germany, although it may be overlooked elsewhere. Lecanora sinuosa is very close to L. hybocarpa, with which it shares thepulicaris -type epihymenium inspersed with fine crystals but differs markedly by its thick thallus and thick and sinuous apothecium margin.  相似文献   

7.
Cell Envelope Morphology of Rumen Bacteria   总被引:26,自引:7,他引:19  
The cell walls of three species of rumen bacteria (Bacteroides ruminicola, Bacteroides succinogenes, and Megasphaera elsdenii) were studied by a variety of morphological methods. Although all the cells studied were gram-negative and had typical cytoplasmic membranes and outer membranes, great variation was observed in the thickness of their peptidoglycan layers. Megasphaera elsdenii evidenced a phenomenally thick peptidoglycan layer whose participation in septum formation was very clearly seen. All species studied have cell wall "coats" external to the outer membrane. The coat of Bacteroides ruminicola is composed of large (approximately 20 nm) globules that resemble the protein coats of other organisms, whereas the coat of Bacteroides succinogenes is a thin and irregular carbohydrate coat structure. Megasphaera elsdenii displays a very thick fibrillar carbohydrate coat that varies in thickness with the age of the cells. Because of the universality of extracellular coats among rumen bacteria we conclude that the production of these structures is a protective adaptation to life in this particular, highly competitive, environment.  相似文献   

8.
Field flow fractionation (FFF) separation techniques have gained considerable success with micron-sized species. Living red blood cells (RBCs) of any origin have emerged as ideal models for cell separation development. Their elution mode is now described as “Lift-Hyperlayer”. Certain separator dimension parameters are known to play a key role in the separation and band spreading process. Systematic studies of channel dimensions effects on RBC retention, band spreading, peak capacity and on a novel parameter described as “Particle Selectivity” were set up by means of a two-level factorial experimental design. From experimental results and statistical calculations it is confirmed that channel thickness plays a major role in retention ratio, peak variance, peak capacity and particle selectivity. Channel breadth strongly influences plate height, with lower impact on peak capacity and particle selectivity. Retention ratio, peak variance and peak capacity observed results are modulated by second-order interactions between channel dimensions. Preliminary rules for channel configurations are therefore set up and depend on separation goals. It is shown that a very polydisperse population is best disentangled in a thin and narrow channel whatever its length. If a mixture of many different micron-sized species is considered (each of limited polydispersities); a thick and broad channel should be preferred, with length modulating peak capacity to disentangle this polymodal mixture.  相似文献   

9.
Here we describe and illustrate a new species, Orchidantha crassinervia sp. nov. (Lowiaceae), from Guangxi Province, China. The species is closely related to O. yunnanensis and O. virosa, but can be distinguished from these species in possessing a very thick midrib of the labellum, fewer flowers per inflorescence and by a shorter plant height. The species is known only from the three populations within 3 km.  相似文献   

10.
Recent studies suggest very low survival of seedlings planted in streamside areas containing thick (>1 m) deposits of legacy alluvial sediments. We planted 2,450 seedlings representing eight species in a streamside area with thick legacy sediments and monitored them for 5 years. The overall survival of approximately 60% (range across species: approximately 38–74%) was surprisingly high and mean overall growth per seedling (approximately 3.27 m) was very good, ranging between 2.5 and 4.7 m depending on tree species. Although both seedling survival and growth exhibited significant spatial variation, none of the results supports the idea that legacy sediment thickness up to 1.5 m is an important factor with regard to success of streamside reforestation. For survival, soil depth was significant for the sediment accretion zone but not the legacy sediment zone. For growth, the response was significant and positive, with the eight species on average growing significantly better as legacy sediment increased in thickness. The results suggest that the presence of legacy sediment up to 1.5 m thick should not preclude the successful restoration of natural forest along stream channels in the eastern Piedmont of North America. Finally, the study suggests that the U.S. federal criteria for reforestation success (i.e. 222 stems per hectare after 5 years) can still be met on legacy sediment sites by increasing the planting density approximately 25% from the required minimum of 296 stems per hectare to 370.  相似文献   

11.
A new Metapeyssonnelia species that comprises up to 7% bottom cover at shallow‐water reef habitats in southwest Puerto Rico is described herein. It forms conspicuous orange encrustations on hard substrata and does not grow on living coral as does its two Caribbean congeners. The new species possesses conspicuous, to 30 cm in extent, tightly adherent crusts up to 950 μm thick, only hypobasal calcification, hypothallial cells arranged in broad flabellules and superficial (raised) tetrasporangial and carposporangial nemathecia. Tetrasporangia are pedicellate, borne laterally from cup‐like cells that are derived from basal paraphysal cells. Tetrasporangia measure up to 120 μm long and individual carposporangia to 80 μm long. The new species differs from other Metapeyssonnelia species developmentally in that perithallial cells at mid thallus height will divide laterally to form a new hypothallium. Small subunit gene sequences relate the new species to the two Metapeyssonnelia species that are previously known from Puerto Rico.  相似文献   

12.
记述采自云南省石林县陆生贝类1新种,即石林管螺Phaedusa shilinensis sp.nov.,文中对新种形态特征、栖息环境进行了描述,并对其相似种进行了分析和讨论。  相似文献   

13.
Gooday AJ  Bowser SS 《Protist》2005,156(1):113-126
We describe a gromiid protist Gromia pyriformis sp. nov., from bathyal depths on the Pakistan margin (NE Arabian Sea), an area characterised by a well-developed Oxygen Minimum Zone (OMZ). The new species is smaller (length usually <1 mm) than the only other described deep-sea gromiid species (Gromia sphaerica) or the well-known coastal species Gromia oviformis. Its identification as a gromiid is based on the test-wall ultrastructure. This includes (i) an outer wall (165-300 nm thick) limited by an electron-opaque layer and perforated by pore structures which typically extend through its entire thickness, and (ii) inner "honeycomb membrane" structures which form a discontinuous sheet (18-20 nm thick) lying parallel to the outer wall. An outermost glycocalyx (approximately 75 nm thick), not observed in other gromiid species, is also present and imparts a finely granular appearance to the outer test surface, as seen by Scanning Electron Microscopy (SEM). Numerous rod-shaped prokaryotes are attached to the exterior of the glycocalyx. Gromia pyriformis sp. nov. typically occurs above the sediment-water interface, attached to the large arborescent foraminiferan Pelosina sp. It is confined to a very narrow bathymetric zone (approximately 1000 m water depth) in the lower portion of the OMZ, where bottom-water oxygen concentrations are approximately 0.2 ml l(-1).  相似文献   

14.
The larva, pupa, male, and female of Simulium bifenestratum n. sp. are described and illustrated. The pupae of the new species have 10 gill filaments, thick at their base and arranged in a three-dimensional way, surrounding the head and thorax. Its pupal cocoon is peculiar, not found in any of the known Brazilian black-fly species; it is very thick and hard with two openings in the anterior region. S. bifenestratum n. sp. was collected in one stream in the Bocaina mountain chain, Atlantic forest, in S?o José do Barreiro county, state of S?o Paulo, in a high (1500 m) natural grassland. Larvae and pupae were collected on the edges of small waterfalls and in places with-high speed laminar water flow, attached to the bedrock.  相似文献   

15.
Summary Structural complexity of the habitat significantly increases population density and number of species in assemblages of predatory gastropod molluscs (families Conidae, Muricidae, Mitridae and Vasidae) on intertidal, generally smooth, horizontal limestone platforms fringing tropical Pacific islands. The important topographic features are physical (depressions partly filled with coral rubble) and biotic (thick algal turf binding sand). Higher population density and species richness in areas with than without such natural refuges, and following experimental addition of artificial refuges on portions of habitat lacking them support this hypothesis. Two species of Drupa differ from the other species present in not utilizing refuges during times of physical stress; this is attributed to their depressed shell and broad, tenacious foot. Highest gastropod densities occur in steep-sided depressions and those containing much coral rubble and sand, suggesting that these are important qualities of refuges. We believe this is the first demonstration of how specific environmental factors affect population density and species diversity of benthic invertebrates in a coral reef-associated habitat.  相似文献   

16.
Different larval planktonic stages of the nudibranch Aegires punctilucens (D'Orbigny) are described. The youngest has a shell of the protoconch type 1 (Thompson) and a bilobed velum. After loss of the shell, the next stage is characterized by a large velum with broad and thick lobes. The mantel covers the body and has tubercles which grow progressively. Spicules appear in the mantle and in the foot; they are simple, triradiate or cross-shaped. A zone of hyaline denticles are present in the stomach lumen.Metamorphosis has been obtained under laboratory rearing. After the gradual resorption of the velum, the animal looks like a small dorid and is grey with white spots. The foot is slender and there are 14 tubercles always arranged in the same way and bristled with spicules.After discussing the species identification, the veliger is compared with other nudibranch larvae. The development of Aegires is very unusual with a two-stage metamorphosis, the first at the time of loss of the shell, and the second at loss of the velum cast. The intermediate stage between those two stages is planktonic.  相似文献   

17.
Pododimeria, containing the brown-spored species P. gallica and P. andina, is expanded to include species with hyaline as well as brown ascospores. Two new hyalodidymous taxa, P. juniperi and P. gelatinosa, are added to the genus. Species of Pododimeria occur as ectocommensals on living shoots of Cupressaceae or Podocarpaceae. Although the superficial mycelium may extend into the labyrinthine chambers enclosed by the imbricated scale leaves of the host, it does not penetrate the cuticle. The tiny, black, subglobose, uniloculate ascocarps taper basally to stromatic stipes. The bitunicate asci are interspersed with pseudoparaphyses composed of broad, irregularly shaped cells that readily break apart. The thick, brown to bluish-green ascocarp wall of P. juniperi has a broad equatorial band of prosenchymatous cells. The ascocarp wall of P. gelatinosa is composed uniformly of subhyaline, gelatinous pseudoparenchymatous cells covered by a dark, amorphous crust.  相似文献   

18.
中国细胸蚁属一新种及一新纪录种(膜翅目,蚁科)(英文)   总被引:1,自引:0,他引:1  
描述细胸蚁属Leptothorax1新种,即郑氏细胸蚁L.zhengiZhouetChen,sp.nov.,报道另1中国新纪录种,堆土细胸蚁L.acervorum(Fabricius,1793)。郑氏细胸蚁,新种Leptothorax zhengiZhouet Chen,sp.nov.(图1~2)新种与堆土细胸蚁L.acervorum(Fabricius,1793)相似,但头部背面明显纵向隆起,侧面观头部背缘至腹缘很厚;头部具粗糙纵皱纹,并腹胸背面具粗糙网纹和刻点;体色深红褐色。正模工蚁,内蒙古贺兰山沙塘子监测站,2010-07-29,陈志林采。副模3工蚁,内蒙古贺兰山水磨沟,2010-07-26,陈志林采。词源:新种种名以郑哲民教授姓氏命名,以示对郑哲民教授对昆虫分类学研究所做出显著贡献的敬意。堆土细胸蚁Leptothorax acervorum(Fabricius,1793)中国新纪录(图3~4)Formica acervorum Fabricius,1793:358.检测标本:20工蚁,黑龙江大兴安岭,2007-08-07,彭一良采;4工蚁,内蒙古贺兰山牧人遗址,2010-07-31,陈志林采。分布:中国(黑龙江,内蒙古);日本,韩国,朝鲜,美国,丹麦。  相似文献   

19.
ABSTRACT. The ultrastructure of meiospores of six different species of Amblyospora found infecting larval mosquitoes of Aedes abserratus, Aedes aurifer, Aedes cinereus, Aedes excruciates, Aedes sticticus , and Aedes stimulans are described. Meiospores of all species exhibited characteristics typical for the genus Amblyospora including: a single nucleus, a large posterior vacuole, a thick undulating exospore and thinner endospore, a bipartite and lamellate polaroplast with more tightly stacked membranes in the proximal region, and an anisofilar polar filament with distal coils reduced in thickness. Distinct differences were found in the arrangement and number/ ratio of coils formed by the broad basal and narrow distal portions of the polar filament. These differences, when quantified and averaged, were unique from all other mosquito-parasitic species that have been examined ultrastructurally. Information on parasite development, natural field prevalence and transmission to suspected intermediate copepod hosts is presented. The creation of six new species, Amblyospora abserrati, Amblyospora auriferi, Amblyospora cinerei, Amblyospora excrucii, Amblyospora stictici , and Amblyospora stimuli is proposed. Synonymies and complete host lists of all forms and species of Amblyospora described from mosquitoes are given.  相似文献   

20.
Histological examination and dissection of a subcutaneous nodule removed from the right infraclavicular region of a 69-year-old woman from Oita, Kyushu, Japan, revealed a young female of Onchocerca dewittei japonica, a common parasite of wild boar in the Oita region. Distinctive morphologic characteristics of this Onchocerca species include the thick cuticle with very prominent and straight transverse ridges overlapping at the lateral sides, the lack of inner striae (scalloping) of the inner cuticle layer, the dorso-ventral symmetry, and the thick somatic muscles. Jointed with previous reports in the past decade, this case confirms the occasional transmission of the parasite from wild boar to humans in Oita.  相似文献   

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