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1.
Zielske, S., Glaubrecht, M. & Haase, M. (2010). Origin and radiation of rissooidean gastropods (Caenogastropoda) in ancient lakes of Sulawesi. —Zoologica Scripta, 40, 221–237. We investigated diversity and origin of as well as relationships among rissooidean gastropods from the ancient lakes of Sulawesi. Analyses of morphological, anatomical and genetic data (16S rRNA, COI and 18S rRNA) revealed ten new species: Sulawesidrobia perempuan sp. n., which is probably parthenogenetic, Sulawesidrobia soedjatmokoi sp. n., Sulawesidrobia mahalonaensis sp. n., Sulawesidrobia anceps sp. n., Sulawesidrobia bicolor sp. n., Sulawesidrobia megalodon sp. n., Sulawesidrobia abreui sp. n., Sulawesidrobia datar sp. n., Sulawesidrobia yunusi sp. n. and Sulawesidrobia towutiensis sp. n. In two cases morphological and anatomical differentiation between pairs of species were not paralleled by genetic differentiation suggesting young speciation events and incomplete lineage sorting as a likely explanation. A Bayesian phylogenetic analysis including representatives of most rissooidean families placed Sulawesidrobia Ponder & Haase 2005 among Tateidae and thus indicated an Australasian origin of the genus. Relationships among the Sulawesian species suggested that isolated Lake Poso was colonised only once whereas the lakes of the Malili system experienced repeated colonizations.  相似文献   

2.
Gastrotricha is a cosmopolitan group of aquatic invertebrates. To date, approximately 765 species have been described. This study is the first to deal with species delimitation and cryptic species of freshwater Gastrotricha. Three commonly encountered species, Heterolepidoderma ocellatum, Lepidochaetus zelinkai, and Lepidodermella squamata, are investigated for cryptic speciation. Most of the material is based on Swedish specimens but closely related species from other parts of the world are also included. Taxonomic revisions are supported by phylogenies based on 18S rRNA, 28S rRNA, and COI mtDNA of freshwater Chaetonotidae from several genera and inferred from Bayesian and maximum likelihood approaches. Heterolepidoderma ocellatum f. sphagnophilum is raised to species level, under the name H. acidophilum n. sp. Moreover, genetic data based on COI indicate large variation between two morphologically very similar groups of Lepidodermella squamata. The extent of cryptic speciation in L. zelinkai appears low. Based on the phylogenetic hypothesis presented in this article, the new species, Lepidodermella intermedia n. sp., from northern Sweden is also described. The phylogenetic hypothesis generated shows that Chaetonotidae is a non-monophyletic group.  相似文献   

3.
Morphological studies of eleven new species in the family permitted reconstruction of progressive evolutionary lines, and this strongly implies progressive evolutionary lines for other acoela. Solenofilomorpha funilis n. sp., Myopea crassula n. g. n. sp., M. latafaucium n. sp., Fusantrum rhammiphorum n. g. n. sp. and Endocincta punctata n. g. n. sp. are described from the coast of South Carolina, U.S.A., and S. guaymensis n. sp. is described from the Gulf of California. Five additional unnamed species from the U. S. Pacific Coast, Sweden and Tunisia are briefly described. Two species groupings were based on correlation between two different arrangements of pharynx muscles and trio arrangements of antrum muscles and further correlations with lesser characters. The membership of the two groupings in a single family make it clear that evolution proceeded by addition of structures to a less complex common ancestor. Functional and behavioral considerations support the evolutionary path drawn from morphology. Distinctive statocyst structure, ciliary interconnections and sperm morphology shared by acoels show them to have a common ancestry, but clearly different pharynges and male structures cannot be consistent with evolution by reductions. A common ancestor of low complexity has probably given rise to several partly parallel evolutionary lines which together form the structurally diverse Acoela. The history of acoel systematics is also briefly summarized.  相似文献   

4.
Nemertodermatida are microscopically small, benthic marine worms. Specimens of two nominal species, Sterreria psammicola and Nemertinoides elongatus from 33 locations worldwide were sequenced for three molecular markers. Species delimitation and validation was done using gene trees, haplotype networks and multilocus Bayesian analysis. We found 20 supported species of which nine: Nemertinoides glandulosum n.sp., N. wolfgangi n.sp., Sterreria boucheti n.sp., S. lundini n.sp., S. martindalei n.sp., S. monolithes n.sp., S. papuensis n.sp., S. variabilis n.sp. and S. ylvae n.sp., are described including nucleotide-based diagnoses. The distribution patterns indicate transoceanic dispersal in some of the species. Sympatric species were found in many cases. The high level of cryptic diversity in this meiofauna group implies that marine diversity may be higher than previously estimated.  相似文献   

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The identification of members of the Onchidiidae is based on morphological characters; this is often time-consuming and can be inconclusive. In order to explore the species diversity of onchidiids in China, we provide a phylogeny constructed using partial sequences of two mitochondrial genes (16S rRNA and COI) and one nuclear ribosomal RNA gene (28S rRNA) from 32 samples comprising five genera. The topology, using both Bayesian and Maximum Likelihood inference methods, showed that the taxa clustered in two main groups of six species, one of which included Platevindex mortoni, Platevindex sp. and Onchidium ‘struma’; the other included Paraoncidium reevesii, Onchidella sp. and Peronia verruculata. It is clear that COI will be useful in discriminating onchidiid species-group taxa.  相似文献   

9.
To more confidently assess phylogenetic relationships among astome ciliates, we obtained small subunit (SSU) rRNA sequences from nine species distributed in six genera and three families: Almophrya bivacuolata, Eudrilophrya complanata, Metaracoelophrya sp. 1, Metaracoelophrya sp. 2, Metaracoelophrya intermedia, Metaradiophrya sp., Njinella prolifera, Paraclausilocola constricta n. gen., n. sp., and Paraclausilocola elongata n. sp. The two new species in the proposed new clausilocolid genus Paraclausilocola n. gen. are astomes with no attachment apparatus, two files of contractile vacuoles, and an arc-like anterior suture that has differentiations of thigmotactic ciliature on the anterior ends of the left kineties of the upper surface. Phylogenetic analyses were undertaken using neighbor-joining, Bayesian inference, maximum likelihood, and maximum parsimony. The nine species of astomes formed a strongly supported clade, showing the subclass Astomatia to be monophyletic and a weakly supported sister clade to the scuticociliates. There were two strongly supported clades within the astomes. However, genera assigned to the same family were found in different clades, and genera assigned to the same order were found in both clades. Thus, astome taxa appear to be paraphyletic when morphology is used to assign species to genera.  相似文献   

10.
Hardy, D. E. (Department of Entomology, University of Hawaii, Honolulu, Hi., USA.) Pipunculidae (Diptera) of the 1934 Swedish expedition to Burma. Zool. Scripta 1(3–4): 121–138, 1972.–The collection of Pipunculidae made in Burma by Rene Malaise contained approximately forty species in five genera and four subgenera and is probably a thorough sampling of the species which occur in the Kambaiti area of N.E. Burma. Eleven new species are being described: Dorylomorpha latifrons sp.n., D. stenozona sp.n., Pipunculus (Cephalops) dolosus sp.n., P. (Cephalops) fimbriatus sp.n., P. (Cephalops) validus sp.n., P. (Cephalosphaera) reduncus sp.n., P. (Cephalosphaera) tingens sp.n., P. (Eudorylas) burmanicus sp.n., P. (Eudorylas) colossus sp.n., P. (Eudorylas) giganteus sp.n., and P. (Eudorylas) malaisei sp.n. Several other species, probably new ones, are indicated but not being described until further specimens can be studied. The majority of the species are new records for Burma.  相似文献   

11.
Apusomonads are cosmopolitan bacterivorous biflagellate protists usually gliding on freshwater and marine sediment or wet soils. These nanoflagellates form a sister lineage to opisthokonts and may have retained ancestral features helpful to understanding the early evolution of this large supergroup. Although molecular environmental analyses indicate that apusomonads are genetically diverse, few species have been described. Here, we morphologically characterize 11 new apusomonad strains. Based on molecular phylogenetic analyses of the rRNA gene operon, we describe four new strains of the known species Multimonas media, Podomonas capensis, Apusomonas proboscidea, and Apusomonas australiensis, and rename Thecamonas oxoniensis as Mylnikovia oxoniensis n. gen., n. comb. Additionally, we describe four new genera and six new species: Catacumbia lutetiensis n. gen. n. sp., Cavaliersmithia chaoae n. gen. n. sp., Singekia montserratensis n. gen. n. sp., Singekia franciliensis n. gen. n. sp., Karpovia croatica n. gen. n. sp., and Chelonemonas dolani n. sp. Our comparative analysis suggests that apusomonad ancestor was a fusiform biflagellate with a dorsal pellicle, a plastic ventral surface, and a sleeve covering the anterior flagellum, that thrived in marine, possibly oxygen-poor, environments. It likely had a complex cell cycle with dormant and multiple fission stages, and sex. Our results extend known apusomonad diversity, allow updating their taxonomy, and provide elements to understand early eukaryotic evolution.  相似文献   

12.
沈硕 《微生物学报》2017,57(4):490-499
【目的】研究青海察尔汗盐湖地区的可培养中度嗜盐菌的群落结构及多样性。【方法】采用多种选择性培养基进行中度嗜盐菌的分离、培养;通过16S r RNA基因序列扩增、测定,根据序列信息,进行系统进化树构建、群落结构组成分析及多样性指数计算。【结果】从察尔汗盐湖卤水及湖泥中分离到中度嗜盐菌421株,合并重复菌株后共83株中度嗜盐菌。菌株16S rRNA基因序列信息显示,4株中度嗜盐菌为潜在的新分类单元。83株嗜盐细菌分布于3个门的6个科16个属。其中,Bacillus属、Oceanobacillus属和Halomonas属为优势属。多样性结果显示,水样中的菌株多样性高于泥样,而泥样中的菌株优势度高于水样。【结论】察尔汗盐湖中度嗜盐菌具有丰富的遗传多样性,种群种类丰富,优势菌群集中,该盐湖地区存在可分离培养的中度嗜盐菌的疑似新物种。  相似文献   

13.
Two regions of mitochondrial (mt) DNA, cytochrome c oxidase subunit 1 (COI) and 16S rRNA, were sequenced in nine species of Betta from Thailand and Indonesia. Most species showed little intraspecific COI variation (adjusted mean = 0·48%) including the putative species Betta sp. Mahachai, but one species (Betta smaragdina) included three lineages showing much greater divergence (7·03–13·48%) that probably represent overlooked species. These findings were confirmed by maximum likelihood analysis and Bayesian inference, which revealed well‐supported corresponding monophyletic clades. Based on these results and morphological differences, the putative species Betta sp. Mahachai from central Thailand is a species distinct from other members of the B. splendens group and represents a new and hitherto undescribed species. Furthermore, this study also demonstrated the probable existence of two overlooked Betta species found in the Khorat plateau basin, illustrating the utility of mitochondrial genetic markers in the revelation of overlooked diversity.  相似文献   

14.
Based on fifteen Archaeognatha (=Microcoryphia) specimens from Myanmar (Burmese) amber, including males, females and immatures, two new genera and four species, Cretaceomachilis longa sp.n ., Unimeinertellus abundus gen. et sp.n. , U. bellus sp.n. and Nullmeinertellus wenxuani gen. et sp.n. , are described. Phylogenetic analyses of taxa in Archaeognatha were conducted using Maximum parsimony and Bayesian inference based on morphological characters and DNA sequence data. Our results confirm the phylogenetic position of the new genera, clarify the monophyly of Meinertellidae and indicate that the ‘paleo‐types’ excluding Ditrigoniophthalmus are nested within the Machilidae group, but suggest that the three subfamilies within Machilidae may be artificial. The diversity of meinertellids with derived characters found from the Cretaceous indicate that the divergence time of Machilidae and Meinertellidae is much earlier than the Cretaceous. We propose the possibility that Meinertellidae might have originated on Gondwana.  相似文献   

15.
We discovered a new brackish water oxytrichid Pseudocyrtohymena koreana n. g., n. sp. in South Korea and investigated the new species on the basis of morphology, ontogenesis, and 18S rRNA gene sequences. The new genus has the 18 frontal‐ventral‐transverse cirri of typical oxytrichids with flexible body, cortical granules, Cyrtohymena undulating membranes (UM), and one left and one right marginal cirral row. Ontogenesis of the new species indicated that dorsal kinety anlage 3 stretches within the parental row without any fragmentations (Urosomoida pattern) and exclusively forms all caudal cirri. The new genus is morphologically similar to Cyrtohymena Foissner, 1989, but has the following distinctive features: (i) caudal cirri absent in dorsal kineties 1 and 2 (vs. present in Cyrtohymena); and (ii) dorsal kinety 3 nonfragmented (vs. fragmented in Cyrtohymena). Further, we collected an additional species Neokeronopsis asiatica Foissner et al. 2010, from King George Island, Antarctica, and the species shares the morphology of UM with Cyrtohymena. Herein, we describe the previously unidentified characteristics of N. asiatica (i.e., cortical granules, body flexibility, contractile vacuole, and 18S rRNA gene sequence). In addition, we obtained two 18S rRNA gene sequences from Cyrtohymena muscorum and Parasterkiella thompsoni to expand samples for phylogenetic analysis. Our 18S rRNA gene tree supports the hypothesis that the Cyrtohymena UM pattern might have evolved several times in hypotrichs (e.g., Neokeronopsidae, Oxytrichinae, and Stylonychinae).  相似文献   

16.
Cyanobacterial diversity from two geographical areas of Baja California Sur, Mexico, were studied: Bahia Concepcion, and Ensenada de Aripez. The sites included hypersaline ecosystems, sea bottom, hydrothermal springs, and a shrimp farm. In this report we describe four new morphotypes, two are marine epilithic from Bahia Concepcion, Dermocarpa sp. and Hyella sp. The third, Geitlerinema sp., occurs in thermal springs and in shrimp ponds, and the fourth, Tychonema sp., is from a shrimp pond. The partial sequences of the 16S rRNA genes and the phylogenetic relationship of four cyanobacterial strains (Synechococcus cf. elongatus, Leptolyngbya cf. thermalis, Leptolyngbya sp., and Geitlerinema sp.) are also presented. Polyphasic studies that include the combination of light microscopy, cultures and the comparative analysis of 16S rRNA gene sequences provide the most powerful approach currently available to establish the diversity of these oxygenic photosynthetic microorganisms in culture and in nature. Electronic Publication  相似文献   

17.
A new soil ciliate, Pseudonotohymena antarctica n. g., n. sp., from King George Island, Antarctica, is described based on live observation, protargol impregnation, and its 18S rRNA gene. The new genus Pseudonotohymena is morphologically similar to the genus Notohymena Blatterer and Foissner 1988 in the following characteristics: 18 fronto‐ventral‐transverse cirri, a flexible body, undulating membranes, dorsomarginal kineties, and the number of cirri in the marginal rows. However, Pseudonotohymena differs from Notohymena particularly in the dorsal ciliature, that is, in possessing a nonfragmented dorsal kinety (vs. fragmented). In addition, the molecular phylogenetic relationship of the new species differs from that of Notohymena species. On the basis of the morphological features, the genetic data, and morphogenesis, we establish P. antarctica n. g., n. sp. In addition, the cyst morphology of this species is described.  相似文献   

18.
The intensive use of chemical fertilizers, monoculture and irrigation with surface saline water has resulted in the deterioration of soil health by enhancing the level of salinity in the Eastern Indo-Gangetic Plains of India. Therefore, diversity of halotolerant bacteria adapted to that environment and possessed the ability to produce plant growth hormones was explored, that could be used for salt stress amelioration. The 16S rRNA gene sequencing and fatty acid methyl ester (FAME) were used for diversity analysis of salt-tolerant bacilli. Among the 95 isolates, 55 strains showed plant growth promotion traits, production of industrially important enzymes (amylase, protease and cellulase) and tolerance to more than 4% NaCl. Using partial 16S rRNA sequences and FAME comparisons, 21 different species of Bacillus and Bacillus-derived genera were identified, viz. Bacillus megaterium, B. subtilis, B. licheniformis, B. firmus, B. horikoshii, B. pumilus, Bacillus sp., B. safensis, B. thuringiensis, B. simplex, B. agri, B. flexus, B. oceanisediminis, B. cereus, B. arsenicus, Paenibacillus dendritiformis, Lysinibacillus sp., L. sphaericus, B. marisflavi, Terribacillus sp., and B. mycoides. These isolates possess the ability to tolerate high salt, form endospores, withstand harsh environments, and also have the potential for plant growth promotion, which could be useful in formulation of new inoculants to enhance the availability of nutrients for crop growth under saline conditions.  相似文献   

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In an effort to broaden our understanding of the biodiversity and distribution of gregarines infecting crustaceans, this study describes two new species of gregarines, Thiriotia hyperdolphinae n. sp. and Cephaloidophora oradareae n. sp., parasitizing a deep sea amphipod (Oradarea sp.). Amphipods were collected using the ROV Hyper‐Dolphin at a depth of 855 m while on a cruise in Sagami Bay, Japan. Gregarine trophozoites and gamonts were isolated from the gut of the amphipod and studied with light and scanning electron microscopy, and phylogenetic analysis of 18S rDNA. Thiriotia hyperdolphinae n. sp. was distinguished from existing species based on morphology, phylogenetic position, as well as host niche and geographic locality. Cephaloidophora oradareae n. sp. distinguished itself from existing Cephaloidophora, based on a difference in host (Oradarea sp.), geographic location, and to a certain extent morphology. We established this latter new species with the understanding that a more comprehensive examination of diversity at the molecular level is necessary within Cephaloidophora. Results from the 18S rDNA molecular phylogeny showed that T. hyperdolphinae n. sp. was positioned within a clade consisting of Thiriotia spp., while C. oradareae n. sp. grouped within the Cephaloidophoridae. Still, supplemental genetic information from gregarines infecting crustaceans will be needed to better understand relationships within this group of apicomplexans.  相似文献   

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