首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 156 毫秒
1.
Four species are recognised in Mouretia, a genus previously thought to be monospecific. Two new species M. vietnamensis and M. larsenii are described, and M. tonkinensis var: inequalis is elevated to the rank of species. All species are illustrated. The chromosome number far M. larsenii is given. The character states for the genus are presented. A comparison between Mouretia and Mycetia show them to share most of their character states. It is suggested that the two genera form a monophyletic group, that should be included in the tribe Hedyotideae.  相似文献   

2.
A survey of pollen morphology in 20 species representing the 11 genera of the North American subtribe Stephanomeriinae by light, scanning electron, and transmission electron microscopy revealed 10 of the 11 genera to have echinate, tricolporate pollen grains, Lygodesmia being the only genus with echinolophate pollen. Sectioned exines of most of the species examined are similar, being composed of ektexine and endexine. The ektexine surface is composed of spines which typically have globose perforate bases. A cavus occurs as a separation between the basis (foot layer) and the columellae in all of the genera examined except Chaetadelpha. Pollen of the two species of Glyptopleura were found to be strikingly different in exomorphology. Pollen of the putatively self-fertile G. marginata has much shorter spines than the closely related G. setulosa. Atrichoseris, Anisocoma, Calycoseris, Glyptopleura, Pinaropappus, Prenanthella, and most species of Malacothrix have pollen which lack paraporal ridges. The remaining genera, Chaetadelpha, Lygodesmia, Rafinesquia, and Stephanomeria have well-developed ridges of fused spine bases around the apertures. Pollen characters, particularly those of the aperture region, have been found to be systematically useful in the subtribe, therefore acetolyzed material gives more useful information than untreated pollen.  相似文献   

3.
Spore morphology of 51 species of Cyclosorus in the Thelypteridaceae from China was investigated using scanning electron microscopy (SEM). The spores are monolete, bilaterosymmetric, ellipsoidal in polar view, and kidney-shaped in equatorial view. On the basis of the variation in their surface ornamentation, the spores fall into three main types. Type I: The surface of spores is echinate or perforate with fimbriate wings. 19 species belong to this type. Type Ⅱ: The surface of spores is cristate. 11 species belong to this type. Type Ⅲ: The surface of spores is echinulate. 10 species belong to this type. The remaining 11 species have spores with mixed surface ornamentation of the above three types, which are considered as intermediate types. The results are valuable for a better understanding of the taxonomy and palynology of the genus Cyclosorus.  相似文献   

4.
Development of the echinate pollen grains inFarfugium (Compositae: Senecioneae) has been studied by a combination of transmission electron microscopy and field emission scanning electron microscopy with a freeze fractured method. The inner surface of the callose wall surrounding each microspore does not possess an echinate pattern before primexine deposition begins. The primexine formation coincides with the initiation of spines. The freeze fractured primexine shows probacula which form transverse rods. The developing exine has an inner spongy substructure. The endexine is formed by the accumulation of the electron dense lamellae with white lines after the dissolution of the callose wall. In the present study, it is confirmed that the developmental process of pollen formation revealed in the field emission scanning electron microscope is consistent with the results obtained using the transmission electron microscope.  相似文献   

5.
6.
A new species of centroderid kinorhynchs, Condyloderes kurilensis sp. nov., collected from muddy sediment at the abyssal plain near the Kuril-Kamchatka Trench, North-West Pacific, is described and illustrated using light and electron microscopy. Previously, members of the genus Condyloderes were found only in nearly shallow water enviroments—C. multispinosus (North Sea), C. paradoxus (Bengal Bay), C. setoensis (Tanabe Bay, Japan), C. storchi (Argentina coast), and C. megastigma (Korea Strait). The new species is characterized by the presence of lateroventral cuspidate spines only on trunk segment 8 in both sexes, paired ventromedial appendages (tubules) on trunk segments 7 and 8 in females only, and dorsolateral spines on trunk segment 10 in males only. Condyloderes kurilensis sp. nov. constitutes the sixth species of the genus Condyloderes described so far and the only second abyssal species of the Kinorhyncha described from the North-West Pacific. A key to the six species of the genus Condyloderes is proposed.  相似文献   

7.
中国奕刺蛾属与焰刺蛾属分类研究   总被引:1,自引:0,他引:1  
武春生  方承莱 《昆虫学报》2008,51(7):753-760
属名Iragoides Hering长期被视为Phlossa Walker的同物异名,两者全世界已知12种。通过解剖我国已有的种类,发现它们的外生殖器结构并不相同,两个属的模式种各代表一个类型,因此,本文复用Iragoides Hering为有效名。奕刺蛾属Phlossa的雄性外生殖器具有刺蛾科的典型结构; 雌性外生殖器的囊导管端部多少有些呈螺旋状,囊突1枚呈新月形。奕焰刺蛾属Iragoides的雄性外生殖器在阳茎端基环两侧有膜质小突起或尾端有微刺突; 雌性外生殖器有相连的2枚囊突,囊突上有许多微齿突。共整理出中国奕刺蛾属Phlossa 4种、焰刺蛾属Iragoides 5种,后者包括1新种--线焰刺蛾I. lineofusca Wu et Fang, 及1新记录种--别焰刺蛾I. elongate Hering。编制了两个属已知种的检索表,提供了成虫彩色照片和外生殖器特征图。模式标本保存在中国科学院动物研究所。  相似文献   

8.
Chelimazocraes liaoi n. g., n. sp. and Chelimazocraes ascidiformis n. sp. (Monogenea: Mazocraeidae) are described from the gills of Clupanodon punctatus (Temminck & Schlegel) in Daya Bay (South China Sea). The new genus is characterised by the following features: (i) the haptor is distinctly separated from the body proper, and the arrangement of the clamps is bilaterally symmetrical but longitudinally heteromorphic; (ii) the anterior three pairs of clamps are of the mazocraeid-type, whereas the fourth pair is of a non-mazocraeid type with three sclerites; (iii) all three pairs of clamps are similar in shape but their size gradually becomes smaller from the anterior to the posterior; (iv) the inner spines of the copulatory organ have a similar shape; and (v) the testes are numerous and arranged longitudinally posterior to the ovary. The two new species are easily distinguished from other members of the Mazocraeidae by the unique structure of the fourth pair of clamps; however, there are some noticeable differences between the two species. The major differences are as follows: (i) the body of C. liaoi n. sp. is significantly larger than that of C. ascidiformis n. sp.; (ii) the anterior three pairs of clamps consist of different sclerites in the two species; and (iii) the copulatory organ has one pair of outer spines and 15–16 pieces of inner spines in C. liaoi n. sp. (vs two pairs of outer spines and 22–26 pieces of inner spines in C. ascidiformis n. sp.).  相似文献   

9.
A comparative survey of the epipharynx and hypopharynx of lithobiomorph centipedes by light and scanning electron microscopy examines 18 species that sample the major groups of both families, the Lithobiidae and Henicopidae. Cladistic analysis of 11 characters of the peristomatic structures together with 29 additional morphological characters serves as a basis for interpreting the evolution of the lithobiomorph peristomatic structures. Scutigeromorpha is used for outgroup comparison in the framework of a homology scheme for the basic components of the epi- and hypopharynx. Compared to other chilopods, the monophyly of Lithobiomorpha is supported by a row of distinctive bottle-shaped gland openings at the border between the labral and clypeal parts of the epipharynx, as well as by a distinctive shape of the hypopharynx. Paired rows of elongate spines on the clypeal part of the epipharynx are an apomorphic character of Lithobiidae. The transformation of these spine rows into a few groups of branching spines is characteristic for the Monotarsobius group sensu Verhoeff. Similar groups of branching clypeal spines characterize the Anopsobiinae within Henicopidae, whereas Henicopinae possess a dense cluster of short, simple spines instead. The recently described genus Dzhungaria is resolved closer to Henicopinae than to Anopsobiinae, a hypothesis supported by a field of grooves on the medial labral part of the epipharynx. Monophyly of Henicopidae does not receive unique support from the peristomatic structures although two homoplastic characters contribute to this node; among these, the reduction of a median spine field between clypeal and labral parts of the epipharynx to a narrow transverse band also supports a close relationship between the Ezembius group and Hessebius within Lithobiidae. An Ezembius+Hessebius clade is additionally supported by the absence of a transverse bulge between the clypeal and labral parts of the epipharynx, a character otherwise present in all lithobiomorph species studied so far. Lithobius is resolved as polyphyletic, with different species being most closely related to such genera as Australobius, Hessebius and Pleurolithobius.  相似文献   

10.
A P Kulakova  Kh Ku 《Parazitologiia》1976,10(5):460-462
In freshwater fishes of North Viet-Nam were found representatives of the family Waretrematidae, Carassotrema koreanum and a new species of this genus, C. ginezinskajae sp. n., close to C. koreanum and differing from it in the structure and extent of yolk glands, relatively larger sizes of the pharynx and suckers, the location of spines and body shape. The described species differs from the other species of this genus, C. mugilicola, in the shape and location of testis, structure and location of yolk glands, intestine extent, size of suckers and pharynx, presence of cirrus, location of spines on the body and in other characters. Asymphylodora pavlovskajae Ha Ky, 1969 and Asymphylodora ginezinskajae Ha Ky, 1969 are reduced to synonyms of Carassotrema koreanum and C. ginezinskajae sp. n.  相似文献   

11.
Two planktonic species of diatoms, Chaetoceros bacteriastroides and C.seychellarus, have been studied by light and electron microscopy. Important features that may be used as taxonomic characters are described. A new subgenus, Bacteriastroidea, is proposed to include C. Bacteriastroides, because of its unique characteristics within the genus. The taxon is considered to be a link between the genera Bacteristrum and Chaetoceros. Morphological and taxonomic affinities between C.seychellarus and other related species of Chaetoceros subgenus Chaetoceros section Borealia, art noted, and a phylogenetic sequence is suggested. Some general evolutionary tendencies are discussed. The known distribution of C. Bacteriastroides and C.seychellarus is revised: both species are restricted to warm waters, but while C. Bacteriastroides shows an Indo-Pacific distribution, C.seychellarus is found in all three oceans.  相似文献   

12.
The Brassoline genus Selenophanes is revised: three new subspecies are described and three lectotypes designated. The nine known holotypes and two of the three lectotypes are figured. Along the Andes there is a fairly close agreement in the distribution of some of the species and subspecies of Selenophanes with the recently recognized endemic centres. East of the Andes there is no close correspondence between subspecies and endemic centres; each subspecies has, in general, a distribution across several centres. A similar distribution has been noted previously in the Brassoline genus Catoblepia.  相似文献   

13.
One new kinorhynch genus and species and one new species from the genus Zelinkaderes are described from sandy sediment off Fort Pierce, Florida. The new genus and species, Tubulideres seminoli gen. et sp. nov. is characterized by the presence of the first trunk segment consisting of a closed ring, the second segment of a bent tergal plate with a midventral articulation and the following nine segments consisting of a tergal and two sternal plates. Cuspidate spines are not present, but flexible tubules are located on several segments, and in particular concentrated on the ventral side of the second segment. Middorsal spines are present on all trunk segments and are alternatingly offset to a position slightly lateral to the middorsal line. Zelinkaderes brightae nov. sp. is characterized by its spine formula in having middorsal spines on trunk segments 4, 6 and 8–11, lateroventral acicular spines on segment 2, lateral accessory cuspidate spines on segments 2 and 8, ventrolateral cuspidate spines on segments 4–6 and 9, lateroventral acicular spines present on segments 8 and 9, and midterminal, lateral terminal and lateral terminal accessory spines on segment 11. The spine formula of Z. brightae nov. sp. places it in a position in between Z. submersus and a clade consisting of Z. klepali and Z. floridensis. The new findings on Z. brightae nov. sp. have led us to propose an emended diagnosis for the genus.  相似文献   

14.
External pollen morphology of 39 species of West Indian Vernonias was examined by light and scanning electron microscopy in conjunction with a systematic revision of these species. There were three distinct types of pollen: Type A: subechinolophate, tricolporate grains with prominent spines; Type B: echinolophate, tricolporate with expanded germinal furrows and coincident polar muri; Type C: echinolophate, tricolporate grains with prominent polar lacunae. Pollen grains intermediate between the major types were found in several species. These same species had very distinct and atypical megamorphologies. In general, pollen types were found to correlate well with classification based on megamorphological characters, particularly at the infrageneric level, and to provide confirmation of subsectional assignments in the genus.  相似文献   

15.
In the context of recent molecular phylogenies of the basal grades of Compositae, we investigated the utility of pollen morphology within the tribe Gochnatieae. The pollen of 64 species of Anastraphia, Cnicothamnus, Cyclolepis, Gochnatia, Pentaphorus, and Richterago was studied using light microscopy and scanning electron microscopy. In addition, three extra-Gochnatieae genera (Ianthopappus, Leucomeris, and Nouelia) were examined as they were traditionally morphologically related to members of the tribe Gochnatieae. Three of the species of Gochnatieae were examined using transmission electron microscopy. Two pollen types, and two new subtypes, have been recognized on the basis of the pollen shape, size, and exine sculpture. The pollen features of Gochnatia sect. Moquiniastrum and G. cordata are similar and distinctive within the genus and support the recently re-circumscribed section Hedraiophyllum. Within the species with echinate pollen surface, the distinctive spine length of Anastraphia supports its recent resurrection as a genus. The identity of Pentaphorus could not be supported by pollen features as was for other morphological characteristics. The pollen features shared across Cyclolepis, Ianthopappus, Leucomeris, Nouelia and Gochnatia sect. Moquiniastrum, as well as those shared by Richterago and Anastraphia could be a result of parallel evolution.  相似文献   

16.
Three new species, Kaempferia larsenii, K. siamensis and K. spoliata are described and illustrated. A key to the Thai species is provided.  相似文献   

17.
18.
The genus Ctenopyge is known mainly from disarticulated sclerites and from rare complete specimens flattened in shales. Hitherto, very few specimens have been found preserved intact and in three dimensions. In a recently discovered fauna, however, in the Peltura minor Subzone in Västergötland, central Sweden, there occur several species of Ctenopyge , of which many are complete and superbly preserved; moreover they occur at all stages of growth. Of these the abundant Ctenopyge ( Eoctenopyge ) angusta Westergård, 1922 is described and reconstructed here as an adult, and the entire ontogeny is documented for all post–protaspid growth stages. Many characters typical of the adult, such as the long genal spines and the caudal spine, develop very early in ontogeny, and the relative dimensions of the cranidium do not greatly change during growth. Macropleural spines, however, develop later. The transitory pygidium, relatively large and shield–shaped in the early meraspid, later becomes very small as the ten thoracic segments are liberated; a median spine develops on the last thoracic segment only at the holaspid stage. Instar groupings can be clearly distinguished for the early stages. Recurrent associations of sclerites are interpreted as moulting configurations. As reconstructed, the genal spines are horizontal and parallel with the extended thorax; an adaptation which presumably allowed the trilobite to rest on the sea floor.  相似文献   

19.
This study investigated the systematics of the megophryid genus Scutiger from eastern and western Nepal using molecular and morphological data. Our results support two divergent lineages, one of which has nuptial spines on the dorsal surface of the first three fingers while the other has spines only on the dorsal surface of the first two fingers. The Ghunsa lineage from eastern Nepal shows significant morphological and molecular differences to other species of genus Scutiger and is here described as a new species. Based on the molecular analysis, the Muktinath lineage from western Nepal is confirmed to be Scutiger boulengeri and represents a species complex widespread throughout the Himalayan region. The newly described taxon is endemic to the eastern Himalayas and currently known only from the Ghunsa valley, Taplejung district, Nepal.  相似文献   

20.
记述中国奇刺(虫兆)属具有6臀刺的1新种,卜氏奇刺姚Friesea buyuni sp.nov..文中给出奇刺(虫兆)属中具有2+2小眼种类的检索表;并给出丽江奇刺(虫兆)的新发布记录.模式标本保存在上海昆虫博物馆.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号