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 15 毫秒
1.
The morphological variation in the annual killifish Austrolebias luteoflamulatus was studied using meristic and pigmentation characters analysed with univariate and multivariate analysis, and morphometric characters analysed with a geometric morphometry approach (thin plate spline). The results showed that morphological variation in this species was associated with a geographical pattern. In the case of meristic and pigmentation characters, the strongest distinction occured in males, while females were more similar among different drainages. Males from Rocha (eastern Uruguay) exhibited the greatest differences from the others. The number of dorsal fin rays and bars on the flanks were the characters that contributed most to this segregation. When morphometrics were considered, the three populations analysed could be distinguished well from each other in both sexes. Some of the characters that contributed to this pattern were dorsal fin origin, position of eyes and length of snout. Since pigmentation characteristics and some characters of the dorsal fin in males were involved in the differences observed, sexual selection could have played an important role in the differentiation of populations of this species. Since Austrolebias luteoflamulatus has a restricted geographical distribution, conservation of this species should include consideration of these populations individually since they might represent different evolutionary units.  相似文献   

2.
3.
The genus Brevipalpus has over 300 species worldwide. The three most important agricultural pest species in the genus, Brevipalpus californicus (Banks), B. obovatus Donnadieu, and B. phoenicis (Geijskes), have been consistently confused and misidentified for more than 50 years. The present study provides a discussion of the characters and character states used to separate these mites. Low-temperature scanning electron microscopy and traditional light microscopy techniques were used to illustrate the subtle morphological differences between these three species. Morphology of the dorsal propodosoma, opisthosoma, and leg chaetotaxy of all three species was examined and compared. The number of dorsal setae, the number of solenidia (omega) on tarsus II, and dorsal cuticular patterns were the most important characters in the identification of Brevipalpus species. B. phoenicis is similar to B. californicus in having two omega on tarsus leg II and different from B. obovatus which has only one omega on tarsus leg II and similar to B. obovatus in having only one pair of F setae (f3), but differing from B. californicus which has two pairs of F setae (f2-3). The dorsal opisthosomal and propodisomal cuticular patterns frequently used to distinguish between these three species are useful but one must be aware that age, feeding, and mounting techniques can affect the appearance of these characters.  相似文献   

4.
A new species of spurdog, Squalus formosus n. sp., from the lower continental shelf and upper continental slope off the coast of Taiwan and southern Japan, is described. It belongs to the 'highfin megalops group', the members of which share a short snout, high dorsal fins, robust dorsal spines, tricuspid denticles and a white posterior caudal margin. Squalus formosus is most similar to Squalus albifrons, a recently described species from eastern Australia, but differs in some morphological characters and fin colouration. Squalus formosus is sympatric with three other species of Squalus in Taiwanese waters, i.e. Squalus brevirostris, Squalus japonicus and Squalus mitsukurii, and can be readily distinguished from these in the following combination of characters: tall and upright first dorsal fin, with a tall and robust spine, short and bluntly pointed snout, white caudal-fin posterior margin and first dorsal fin with a white anterior margin parallel with dorsal spine. This new species was considered by some authors to be conspecific with Squalus blainville from the eastern Atlantic Ocean, but the results of this study reveal that it is probably endemic to Taiwan and southern Japan.  相似文献   

5.
Praelibitia Roewer, 1956 and its type species, Praelibitia titicaca Roewer, 1956, are respectively synonymized with Platygyndes Roewer, 1943 and its type species Platygyndes titicaca Roewer, 1943, and furthermore the genus is transferred from the Gonyleptidae to the Cosmetidae. On the basis of domed and unarmed ocularium, increased number of granules on scutal areas, unarmed dorsal scutum and general body shape, Platygyndes seems to be closely related to Moselabius Roewer, 1956 and Caracarana Roewer, 1956. External morphological characters that are useful to revealing relationships among cosmetid genera are discussed.  相似文献   

6.
Tenualosa ilisha, T. toli and Hilsa kelee are three Indian shad species of the family Clupeidae. In past, relationships among these shads have been explored in few morphological studies but still remain poorly understood. In this study, 120 specimens of three shad species were collected from the wild and a truss network system of 13 landmarks was interconnected to yield 77 size-adjusted characters. Discriminant function analysis (DFA) produced 13 discriminating variables in delineating the three species. The landmark based morphometric distance between origin of dorsal fin and posterior end of eye was the most important character in discriminating the three species. Three prominent characters extracted from DFA (distance between posterior end of operculum and posterior end of eye, distance between origin of dorsal fin and posterior end of eye and distance between insertion of pelvic fin and end of operculum) were used as traditional morphometric characters and their ratio to standard length were found significant in differentiating the three shad species. The present study strongly supports the efficiency of landmark-based morphological characters generated from digital images in discriminating the species and can be used as a rapid diagnostic tool in recognizing them.  相似文献   

7.
近年,作者在安徽淮南大居山陆续发现了数量很多的上新五褶兔化石,其中包括保存较完整的数十个头骨及上百个下颌骨,均产自新洞、无名洞及铁四局洞穴、裂隙堆积,分别记述为大居山上新五褶兔Pliopentalagus dajushanensis sp.nov.和安徽上新五褶兔Pl.anhuiensis sp.nov.两新种。淮南地区的晚新生代洞穴和裂隙堆积十分发育,其中常含有丰富的脊椎动物化石,而且在时、空分布上有一定的规律。区内洞穴和裂隙堆积垂直分布至少有6个水平层,最高的第6层海拔高度为160 m(如大居山老洞),第5层(如大居山新洞、无名洞)及第4层(如大居山铁四局洞穴)的海拔高度分别为130 m和90 m,属于新近纪,常含有丰富的上新五褶兔化石;第3层为第四纪早期(如大居山西裂隙),未见上新五褶兔,代之出现丝绸兔(Sericolagus sp.),第2层为中更新世(如大顶山西裂隙),出现野兔(Lepus sp.)。迄今为止,安徽淮南地区共发现了3种上新五褶兔化石,即淮南上新五褶兔Pl.huainanensis (金昌柱,2004)、大居山上新五褶兔Pl.dajushanensis sp.nov.及安徽上新五褶兔Pl. anhuiensis sp.nov.,至少涉及了3个不同地质时期的动物群:一为Pl.huainanensis,Kowalskia neimengensis,Adcrocuta eximia等代表的老洞晚中新世动物群,二为Pl.dajushanensis sp.nov.和Promimomys asiaticus等代表的新洞早上新世动物群,三为Pl.anhuiensis sp.nov.和Kowalskia yinanensis所代表的晚上新世动物群。淮南地区发现的3种上新五褶兔地史分布较连续,演化特征明显,它们构成上新五褶兔连续的进化系列。从晚中新世至晚上新世,淮南大居山上新五褶兔体型从小变大;p3较原始的釉岛状后内褶沟逐渐向舌侧开放(晚中新世种Pl. huainanensis的后内褶沟均为釉岛状,早上新世种Pl.dajushanensis为83.9%,晚上新世种Pl. anhuiensis为33.3%);p4-m2的前外褶沟逐渐退化,其下跟座舌侧的釉质层越来越变细。依性状分析,安徽发现的3种上新五褶兔化石与日本琉球奄美黑兔(Pentalagus furnessi)具有密切的亲缘关系,但从日本奄美黑兔的p4-m2完全缺失前外褶沟、颊齿褶沟釉质层的褶曲异常复杂等衍生性状看,上新五褶兔和奄美黑兔的系统演化关系较为复杂,尚有待发现更多早更新世的材料进一步探讨。  相似文献   

8.
Impatiens bomiensis, a new species of Balsaminaceae from Bomi County, Xizang, China, is described and illustrated. This new species is similar to Impatiens fragicolor based on morphological characters and molecular data, but differs in the shape of the lower sepal, the dorsal petal and the number of globose glands at petiole base.  相似文献   

9.
Species recognition attributed to the brachiopod family Atrypidae is evaluated based on qualitative and quantified morphological characters. I identified two brachiopod species—Pseudoatrypa lineata and Pseudoatrypa devoniana—from a rich assemblage of brachiopods recovered from the middle Devonian Genshaw Formation of the Traverse Group. Qualitative examination suggested that the former had fine-medium-sized ribbing, a narrow hinge line, widened anterior, moderately steep mid-anterior fold, domal shaped dorsal valve, and an inflated ventral valve in contrast to the coarse ribbing, widened hinge line, narrow anterior, gentle mid-anterior fold, arched-shape dorsal valve, and flat ventral valve of the latter. The shell outline appears rounded for P. lineata and elongated for P. devoniana. Quantitative assessment of the morphological characters on the dorsal, ventral, anterior, and posterior regions of the valves of the two species using geometric morphometric and statistical analyses suggests that the morphologies of the two species are considerably different (P  $ \ll $  0.01). Thus, qualitative differences between the two atrypid species were further corroborated by quantitative results. This emphasizes the fact that these two species of Pseudoatrypa were indeed different from each other. This study highlights the necessity of incorporating quantified morphological characters to successfully investigate the taxonomic distinctness of fossil invertebrates to the species level.  相似文献   

10.
A new species of Cambeva endemic to the Rio Ivaí basin, Upper Paraná basin, is described combining morphological and molecular data. This new species is distinguished from all congeners by characters related to the number of pectoral-fin rays, to the colour pattern of the dorsal and lateral surface of the body, to the presence of diffuse blotches in the ventral surface of body, to the presence of a pelvic-fin and pelvic girdle, to the number of odontodes in the inter-opercular and opercular patches, to the number of dorsal and ventral procurrent rays. In addition, the analysis of mitochondrial DNA sequences identified a satisfactory genetic distance between this new species and its congeners. The new species from the Rio Ivaí reinforces its characteristics as an area of endemism for fishes in the Upper Rio Paraná basin.  相似文献   

11.
Yang Q  Zhu Y  Xiong B  Liu H 《Zoological science》2011,28(2):158-167
A new species of the bitterling genus Acheilognathus, Acheilognathus changtingensis sp. nov., was recently discovered from Changting County in Hanjiang River, Fujian Province, Southeastern China. It can be diagnosed by the following combination of characters: dorsal fin with three simple and 15 (occasionally 14) branched fin rays, anal fin with three simple and 12 (occasionally 11) branched fin rays; dorsal fin pale and anal fin slightly pale; white spots on anal-fin rays forming a transverse band, and anal fin margined with white band in males. Its unique characters are the many dispersed black spots on the dorsal, anal, pelvic, caudal fins, and on the head. Using the mitochondrial cytochrome Jb gene as a molecular marker, we reconstructed phylogenetic trees of A. changtingensis sp. nov. and other species in Acheilognathus to confirm its taxonomic status and study its speciation. Analyses of both morphological and molecular data consistently indicated the taxonomic status of the present new species. The results also show that A. changtingensis sp. nov. and Acheilognathus macropterus are sister species that diverged about 14.50 MYA by geographical isolation.  相似文献   

12.
瓦氏阿猎蝽Agyrius watanabeorum为日本半翅目学者石川忠2002年根据采自泰国北部的标本所命名,其描记较为详细,配有正模的整体黑白照片和部分特征图,但对该种的阳茎结构没有提及。在研究中国和越南的猎蝽时,我们发现了该种。本文中我们重新描述了瓦氏阿猎蝽,绘制了较详细的整体图和局部特征图。阿猎蝽属Agyrius Stal,1863为中国和越南的新记录属,瓦氏阿猎蝽Agyrius watanabeorum Ishikawa,2002为中国和越南的新记录种;其在中国和越南的分布也是该属种最北的分布记录。  相似文献   

13.
Potamotrygon marquesi, sp. nov., is described and compared with other species of Potamotrygon occurring in the Amazon Basin. The identity of this new species is supported by an extensive external and internal morphological study including coloration pattern, squamation, skeleton and ventral lateral-line canals. Morphometrics and meristics were used to further distinguish P. marquesi from congeners. Potamotrygon marquesi was first considered to fall within the range of variation found in P. motoro. However, even with an extensive variation in coloration observed in P. motoro, this new species presents a series of autapomorphies that confidently distinguishes it from what is understood as the morphological variation found in P. motoro. Additional morphological characters that diagnose P. marquesi include three angular cartilages, asymmetrical star-shaped denticles, a single regular row of spines on tail dorsum, lateral row of caudal spines near the sting insertion, dorsal disc background in beige and grey mixed with shades of grey and bearing open and closed bicolored rings, among others. Although presenting a gap of distribution along the west–east extension of the Amazon Basin, its diagnostic charactistics are consistent in both recorded regions. Our study supports the need for many morphological characters to robustly distinguish members of Potamotrygoninae considering their extremely variable dorsal disc color pattern.  相似文献   

14.
兰属、兜兰属、石斛属植物叶片的扫描电镜观察   总被引:10,自引:0,他引:10  
对兰科植物的兰属、兜兰属及石斛属16个种折叶片及其横断面进行了扫描电镜的观察。兰属各种叶片上表皮细胞均为矩形,上表皮细胞表面具小乳突或不明显突起。石斛属及兜兰属的各个种上下表皮细胞均为多边形,但石斛属表皮细胞表面无坦无纹饰,而兜兰属花叶类上表皮细胞表面明显呈乳突状,绿叶类呈龟背状隆起。兰属及石斛属叶片叶肉组织没有栅栏组织及海绵组织的分化,而兜兰属的绿叶类叶肉不分化;花叶类叶肉有分化。  相似文献   

15.
Higashi R  Tsukagoshi A 《ZooKeys》2012,(193):27-48
Two new species of the interstitial ostracod genus Parvocythere, Parvocythere gottwaldisp. n. and Parvocythere gracilissp. n., are herein described. Although these two new species are clearly distinguishable by certain morphological differences in elements of the male copulatory organ, and the carapace, they share the following simplified characters of the appendages and male copulatory organ: antennular fourth podomere with no suture; reduced claws on the distal end of antenna; and asymmetric male copulatory organ. The morphological differences among known and new Parvocythere species suggest that the species of this genus can be classified into two groups by the presence/absence of the suture on the antennular fourth podomere. The "Group S" is characterised by the presence of the antennular suture, and all species of this group have a two-clawed antenna and symmetric male copulatory organ, characters which are generally seen in cytheroid ostracods. The species belonging to "Group N" are characterised by the absence of the suture, regarded as a pedomorphic character, show the following characters: two clawed or one clawed antenna, and symmetric or asymmetric male copulatory organ. The morphological variation within Group N includes reductive characters regarded as an adaptation to the narrow spaces of the interstitial environment of a sandy beach. These intrageneric morphological variations of the exclusively interstitial genus Parvocythere suggest the possibilities that Group N might be derived from Group S, and that some adaptive characters to an interstitial environment could have developed after the colonisation of these environments.  相似文献   

16.
Integrative taxonomy is considered a reliable taxonomic approach of closely related and cryptic species by integrating different sources of taxonomic data (genetic, ecological, and morphological characters). In order to infer the boundaries of seven species of the evacanthine leafhopper genus Bundera Distant, 1908 (Hemiptera: Cicadellidae), an integrated analysis based on morphology, mitochondrial DNA, and hyperspectral reflectance profiling (37 spectral bands from 411–870 nm) was conducted. Despite their morphological similarities, the genetic distances of the cytochrome c oxidase subunit I (COI) gene among the tested species are relatively large (5.8–17.3%). The species‐specific divergence of five morphologically similar species (Bundera pellucida and Bundera spp. 1–4) was revealed in mitochondrial DNA data and reflectance profiling. A key to identifying males is provided, and their morphological characters are described. Average reflectance profiles from the dorsal side of specimens were classified based on linear discriminant analysis. Cross‐validation of reflectance‐based classification revealed that the seven species could be distinguished with 91.3% classification accuracy. This study verified the feasibility of using hyperspectral imaging data in insect classification, and our work provides a good example of using integrative taxonomy in studies of closely related and cryptic species. © 2015 The Linnean Society of London  相似文献   

17.
Diversity in glomalean fungi is manifested at the molecular, morphological, and ecological levels. Characters at any of these levels can be ordered into hierarchical patterns defining taxonomic groups if they are conserved enough to be heritable through geologic time in all descendants of a common ancestor. At present, only morphological characters associated with mode of spore formation and in subcellular structure of spores are sufficiently stable and diverse to recognize at least 150 species. Ontogenetic comparisons indicate that species integrity, despite asexual reproduction, is the result of rigid internal constraints imposed on variation during the process of spore subcellular differentiation. Epigenetic factors dominate because the differentiation sequence is linear and each new stage is causally linked to preceding stages. Some morphological characters of the fungal mycelium also exist, but they define more inclusive groups at the family level and above. Most diversity in the mycorrhizae consists of life-history traits associated with abundance and architecture of fungal components, their rate of formation and longevity, and their cost in the symbiosis. These characters participate in processes at the molecular and ecological levels, so they are autonomous from morphological determinants. They often are labile or affected by external environmental conditions, so fewer stable taxonomic characters are likely to be discovered. Instead, molecular and ecological diversity has greater potential to define; (a) niche specificity of organisms/populations and (b) causal processes linked to host-fungus compatibility and mycorrhizal efficiency. Any taxonomic characters that relate to mycorrhizal functions will come only from comparative studies involving organisms from shared habitats rather than those having shared spore morphologies.  相似文献   

18.
通过形态特征的测量和线粒体DNAcyt b基因序列分析,发现了弹涂鱼属的1个中国新纪录种,大鳍弹涂鱼Periophthalmus magnuspinnatus.新纪录种与中国近缘种弹涂鱼P.modestus的主要形态区别为:第1背鳍大而高,第1鳍棘呈丝状延长,各鳍棘尖明显伸出鳍膜;第2背鳍各鳍棘中部以下颜色均一,无黑斑;第1背鳍和第2背鳍基部之间间距较小;左右腹鳍基部愈合处凹陷较浅.序列分析表明,新纪录种与形态近似种弹涂鱼P.modestus的cyt b基因全序列平均K 2-P遗传距离高达17.3%,在分子系统树上也聚为分别属于两个不同的支序,证实了新纪录种的有效性.新纪录种在中国的渤海、黄海、东海和南海的沿海都有分布记录.  相似文献   

19.
《Nordic Journal of Botany》2008,25(1-2):27-30
Impatiens angulata S. X. Yu, Y. L. Chen et H. N. Qin sp. nova (Balsaminaceae), a new species from Guangxi, China, is described and illustrated. This species is close to I. hainanensis in morphological characters . Both have succulent stems, 4 lateral sepal connected upper lobes of lateral united petals, but are distinguished by the base of stems with 6–9 ridges, leaves oblong or oblanceolate, the outer lateral sepals with 9 veins, inner lateral sepals ovate and dorsal sepal with deep bilobate spur.  相似文献   

20.
Nematodes belonging to the genus Physaloptera Rudolphi, 1819 were obtained from the Lybian jird Meriones libycus and the social vole Microtus socialis in the Gobustan area as a result of helminthological research. These nematodes significantly differed from other species of the genus in morphological and morphometric characters. In the present paper, they are described as the new species Physaloptera musayevi sp. n.  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