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.
Juan C. Paggi 《Hydrobiologia》1992,231(3):141-151
I. elegans n.sp. from the Parana River, northeastern Argentina is proposed and its morphological features are compared with those of the apparently related I. agilis. Its outstanding characteristics are the long 2rd to 5th setae of ventral margin of the valves, the rudimentary nature of defensive setae, the low number of spines in the preanal lobe of postabdomen and the unequality of the length of the setae in the outer distal lobe of first trunk limbs.Finding of this new species suggests that I. agilis would be a complex of species and its records should be revised.  相似文献   

2.
3.
Kotov and Štifter (2006) revised the taxonomy of the genus Ilyocryptus Sars, 1862 (Branchiopoda: Anomopoda: Ilyocryptidae) and concluded that 28 species can be recognized as valid for the world fauna. In order to test phylogenetic relationships between the species and to contribute to a better understanding of the genus, a cladistic (using branch‐and‐bound search) analysis was conducted for 25 Ilyocryptus species (two of them with two subspecies). In total, 32 morphological characters were used. An evolutionary‐morphological interpretation of the results was also made. Phylogenetic analysis revealed that Ilyocryptus elegans is an earlier derived member of the genus, while other species are separated into two main branches: agilis ‐ and sordidus ‐lines (without reference to type of moulting). Species with incomplete moulting and species with complete moulting do not form separate clusters, suggesting an independent origin of incomplete moulting within different species groups. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   

4.
S. Tanaka 《Limnology》2001,2(3):219-222
Three species of Ilyocryptus, Ilyocryptus sp., I. cuneatus Stifter 1988, and I. spinifer Herrick 1882, are newly recorded from the Japanese islands. The first two species were found separately at two sites in Hokkaido and the third at eight sites in Honshu and Kyushu. Their morphological features are briefly described based on parthenogenetic females. Received: May 21, 2001 / Accepted: July 23, 2001  相似文献   

5.
6.
A new species of Cladocera, Moina mukhamedievi from ricefields of Uzbekistan, is described. It is compared with the related species M. dubia, M. brachiata, M. oryzae. This revised version was published online in September 2006 with corrections to the Cover Date.  相似文献   

7.
A new species of Ilyocryptus Sars from Çildir Lake in Kars is described and figured. In external morphology, Ilyocryptus anatolicus n. sp. resembles partly I. sordidus (Liévin) and I. spinosus tifter, but it shows several morphological differences in shape and armature of the postabdomen and in the defensive spines on the posterior margin of the carapace.  相似文献   

8.
Kotov  Alexey A. 《Hydrobiologia》2000,428(1):115-128
The morphology of Ilyocryptus tuberculatus Brehm, 1913 is redescribed, based on material from the Niger basin, Africa. The species name was given by Brehm erroneously, because under an optical microscope he mistook internal structures (the columns between the outer and inner walls of the valves) for the tubercules on the valve surface. But this species is undoubtedly valid, and `incorrect' species names must be conserved. Differences between I. tuberculatus and the most similar I. agilis (probably absent from the majority of African waters), I. spinifer (common in Africa), and some other species are discussed. Currently, I. tuberculatus is known for the Central African Republic, Mali and Niger.  相似文献   

9.
10.
Two new species of the genus Diaphanosoma, D. oligosetum and D. dorotheae, from Louisiana and North Carolina respectively, are described. The former species has large head with protruding dorsal part, large lanceolate spine on the basipodite's distal outer end, an extremely reduced number of antennal setae, up to six in adult specimens, and unique armament of valve margin. On the whole, it shows the pronounced combination of primitive and specialized morphological traits. D. dorotheae is a member of D. brachyurum species group differing from its other known representatives in presence of a small but very conspicuous spine on the end of proximal segment of antennal exopodite and a variable number of setae (seven or eight) on the distal segment of the branch. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   

11.
Populations of theDaphnia hyalina-galeata complex from Central, North and South Europe have been compared morphologically. The main purpose of this investigation is delimitation of the critical speciesDaphnia galeata, based on a thorough examination of the original materials from G. O. Sars' collection, and taking into account hitherto overlooked or insufficiently appreciated characters. According to their morphology and ecology,Daphnia hyalina, Daphnia galeata andDaphnia cucullata have to be treated taxonomically as separate species. In view of the short and high antennula mound and other morphological characteristics,Daphnia gracilis Hellich andDaphnia hyalina lacustris sensu Lilljeborg belong to the speciesDaphnia galeata. In the common range ofDaphnia galeata andDaphnia cacullata there occurs quite frequently an intermediary form, which according to genetic evidence is a hybrid of these two species. Although apparently this hybrid form is stabilized genetically to a large extent and is capable of identical reproduction, it should not be considered as a species in the usual sense.The present work intends to put the notoriously confused systematics of theDaphnia hyalina-galeata complex on a firm basis. It concludes with a key, which should enable also non-specialists to identify uniquely the three species and the hybrid form in question.  相似文献   

12.
Sorex rohweri sp. nov. is described on the basis of a series of specimens from the Olympic Peninsula and adjacent western regions of Washington State, USA, and southwestern British Columbia, Canada. It has been misidentified as Sorex cinereus Kerr, 1792, which occurs in the Cascade Range in west-central Washington, in coastal British Columbia, and regions farther to the northeast. The new species is distinguished from S. cinereus by numerous morphological characters: differences in craniodental dimensions; different location and form of the medial tines of the upper incisors; presence of patent postmandibular foramina; different intensity and distribution of dental pigmentation; and different form of the glans penis, along with other details. The combination of characters also separates it from sympatric species of Sorex. Phylogenetic inference of cytochrome b sequences from two specimens of the proposed new species shows them to be distinct from Sorex cinereus and from five sympatric Sorex species, supporting their designation as members of a new species.  相似文献   

13.
A new species of the genus Stylodrilus is described from phreatic waters in California, North America. Tubular atria with bulbous penes and spermathecae with broad and short ducts characterize the new species. The habitat of Stylodrilus californianus n. sp., confirms that the distribution of the genus Stylodrilus in the Neartic biogeographical zone is mainly associated with subterranean waters.  相似文献   

14.
朱一凡  郭林 《菌物学报》2011,30(4):526-528
在海南省炭角菌的调查研究中,发现一个生长于枯死落叶上的炭角菌属新种。它子座单个,顶端不孕,针刺状,柄细长,多毛,表面呈灰色,有圆锥状孔口。子囊壳埋生。通过与其他9种叶生炭角菌进行比较,确定为海南炭角菌 Xylaria hainanensis新种。  相似文献   

15.
Based on field investigations as well as morphological and molecular systematic studies we found a new species of Bothriospermum which can be easily distinguished from all other known congeneric species by its unlobed faucal appendages and very long styles. We conducted molecular phylogenetic analyses based on a combined dataset from nrITS, plastid rps16, trnL‐trnF and trnG‐trnS regions. The results indicated that the new species indeed belongs in Bothriospermum and that it is well separated from other congeneric clusters, but that the genus Bothriospermum is paraphyletic with Nihon and Thyrocarpus clusetered within it. As a result, Bothriospermum longistylum sp. nov. is described and illustrated here. A revised key to species of Bothriospermum and a distributional map are also presented.  相似文献   

16.
During the wet season of 1999–2000, we studied the effects of the hydroperiod and other physical and chemical variables on planktonic copepod communities from six stations in Everglades National Park. Two stations were located in a slough (Taylor Slough 1, Taylor Slough 2) and four stations in the marl prairies of the Rocky Glades (Long Pine Key 7, Long Pine Key 8, Pa-hay-okee, Chekika). During the period of investigation, Taylor Slough sites had the longest hydroperiods, together with Pa-hay-okee, which is located near the eastern edge of Shark River Slough. Long Pine Key 7 and Long Pine Key 8 had the shortest hydroperiods, and Chekika had an intermediate hydroperiod. The pineland edge sites in the southern Rocky Glades (Long Pine Key) had higher numbers of individuals, and high percentages of larval stages, especially at the end of the wet season. The pineland ecotone is morphologically very heterogeneous, with solution holes in the limestone bedrock that provide below-ground refugia when there is no water on the marsh surface. The slough stations had the lowest numbers of individuals, as well as Chekika in the Rocky Glades, probably as a consequence of the altered water quality and hydropatterns caused by water management structures and operations We collected two species of calanoids, 18 cyclopoids, and three harpacticoids. The most abundant species were Acanthocyclops robustus, Tropocyclops prasinus mexicanus, Arctodiaptomus floridanus, Mesocyclops americanus, Macrocyclops albidus, Osphranticum labronectum, Microcyclops varicans, Microcyclops rubellus, Eucyclops conrowae, and Mesocyclops edax. Of these species, T. prasinus mexicanus and A. floridanus seemed to be adapted to short-hydroperiod habitats, M. rubellus and M. varicans to longer hydroperiod habitats, and E. conrowae to high conductivity habitats. Acanthocyclops robustus, M. albidus, and O. labronectum were dominant regardless of hydroperiod. As regards the temporal distribution, A. robustus was abundant throughout the entire wet season, M. edax, M. rubellus, M. americanus and M. varicans were most abundant in mid-wet season, in September–October, and T. prasinus mexicanus, M. albidus, and E. conrowae were abundant late in the wet season, in winter. The two calanoids only slightly overlapped in time: A. floridanus was abundant at the beginning of the wet season, in July–August, and O. labronectum was abundant at the end of the wet season, in December.  相似文献   

17.
Ferula paeoniifolia X. G. Ma & C. Y. Liao sp. nov., from Sichuan Province, Southwest China, is described and illustrated. The new species is most similar to F. kingdon‐wardii Wolff in morphology, but differs significantly in its ternate‐2‐pinnate compound leaves with much broader leaflets. The key morphological characteristics and nuclear ribosomal internal transcribed spacer (ITS) region were also compared between F. paeoniifolia and its relatives.  相似文献   

18.
The genus Bosmina can be differentiated into four subgenera: 1. Bosmina s. str. BAIRD , 1845, 2. Eubosmina SELIGO , 1900, 3. Neobosmina LIEDER , 1957, and 4. Sinobosmina LIEDER , 1957. Subgeneric discrimination is based upon several features of the females (postabdominal claw, serration of the mucro, patterns of the lateral head pores) and, mainly, upon certain differences in the morphology of the male (postabdomen and, according to LILLJEBORG 1900, BURCKHARDT 1924 and KOŘINEK 1971, the first leg). The distribution of the Bosmina subgenera throughout the world varies: Bosmina s. str. is distributed worldwide (except for Australia?), Eubosmina is holarctic, Neobosmina has been found in Africa, the neotropical zone, Australia and Oceania, and Sinobosmina occurs in East and South-East Asia.  相似文献   

19.
Trachyspermum reginei Ajani & Mozzaff. sp. nov., is described and illustrated as a new species from Chaharmahale Bakhtiari province, SW Iran. The new species differs from its closest relative T. confusum, endemic to Afghanistan, mainly by stem, leaf and fruit morphological characters. Its taxonomic relationships with T. podlechii and T. ammi are also discussed. The new species is threatened by different factors and its protection is recommended.  相似文献   

20.
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