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1.
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The new enchytraeid species Lumbricillus healyae sp. n. is described from freshwater streams, with well-oxygenated and poorly mineralised waters, situated in Byers Peninsula (Livingston Island, South Shetland Islands, Antarctica). Lumbricillus healyae sp. n. is morphologically close to L. antarcticus and L. incisus, and it is mainly distinguished by the structure of the spermatheca with a short, distinct ectal duct, the oval penial bulb (greatest diameter in the transverse body axis) associated with strong dorso-ventral muscular fibres, and a protrusible pseudopenis. A second undetermined Lumbricillus species is described from a small stream. Study specimens are not fully mature; however, the highly irregular form and size of the testis-sac lobes and the absence of a penial bulb encapsulated under a muscular layer are remarkable. It is probably related to a small group of Lumbricillus species reported from the Antarctic maritime region (L. colpites, L. griseus and L. aestum), characterised by the structure of the male duct, which ends in a simple pore surrounded by glands.
Eugenio RicoEmail:
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3.
The antibacterial properties of Euglena viridis, collected from a freshwater pond at the Central Institute of Freshwater Aquaculture (CIFA), Bhubaneshwar, India, were tested against various strains of virulent pathogens viz. Pseudomonas putida(PP1, PP2),P. aeruginosa (PA1, PA2, PA3, PA4), P. fluorescens (PF1, PF2, PF3, PF4), Aeromonas hydrophila (AH30, AH31, AH32, AH34), Edwardsiella tarda, Vibrio alginolyticus (VA1),V. anguillarum(VN1, VN2 & VN3), V. fluvialis (VF1), V. parahemolyticus (VP1) and V. harveyi (VH1) andEscherichia coli(O115, O1, O156, O164, O111 & O109). Four organic extracts viz. methanolic, ethanolic, acetone and acetone/ethanol of theE. viridis showed moderate to high antibacterial activity to all the bacterial pathogens. Rotavapor extraction products showed higher sensitivity in comparison to cold and hot extractions.  相似文献   

4.
A new species,Bactris pliniana, from the Amazon region is described and illustrated. Its relationships within the Piranga group are discussed. Studies on the Flora of the Guianas 78.  相似文献   

5.
Sarcostemma areysianum Bruyns is described from the southern mountains of Yemen. It appears to be most closely related to S. arabicum Bruyns & P. Forst. and S. socotranum Lavranos, differing from both by the taller gynostegium with narrow, mostly acute inner corona lobes. A key to the species from Arabia and Socotra is provided.  相似文献   

6.
Three marine scuticociliates, Falcicyclidium fangi nov. gen., nov. spec., Falcicyclidium atractodes nov. spec., and Cristigera media Kahl, 1928 were investigated using live observation and silver impregnation methods. The genus Falcicyclidium is distinguished by the combination of: (i) dorsoventrally flattened body, (ii) hook-like (falciform) paroral membrane, (iii) anterior end of paroral membrane posterior to anterior end of membranelle 1, and (iv) multiple caudal cilia. Falcicyclidium fangi nov. spec., the type of the new genus, can be recognized by the combination of its large size, extremely dorsoventrally flattened (3:1) body, consistently 10 somatic kineties, and the broad, elongate buccal area occupying 60% of the body length. Falcicyclidium atractodes nov. spec. is mainly characterized by a unique spine projecting from both the anterior and posterior end. The uncommon form, Cristigera media is redescribed based on the population from Qingdao, the statistic data and additional features, especially the morphology of the living cells, are documented.  相似文献   

7.
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The freshwater sculpins, genus Cottus (Teleostei; Cottidae), comprise bottom-dwelling fishes that exhibit various life-history styles, having radiated throughout Northern Hemisphere freshwater habitats. The phylogenetic relationships among Cottus and related taxa were estimated from mitochondrial DNA 12S rRNA and control region (CR) sequences, the freshwater sculpins examined falling into five lineages (A-E). Lineage A consisted of Trachidermus fasciatus and C. kazika, both having a catadromous life-history. The remaining species (lineages B-E) spawn in freshwater habitats regardless of life-history (amphidromous, lacustrine or fluvial), suggesting that the various life-history types post-dated a common ancestor of lineages B-E. Molecular clock estimates suggested a Pliocene-Pleistocene radiation (or Miocene-Pliocene from the alternative clock) of lineages B-E. In eastern Eurasia, speciation with life-history changes to amphidromous or fluvial styles has apparently occurred independently in some lineages, as a general pattern. Mitochondrial DNA CR phylogeny showed the monophyletic Baikalian cottoids (Cottoidei) to be nested within Cottus and Trachidermus, suggesting that the former ecologically and morphologically divergent cottoids may have originated from a single lineage which invaded the ancient lake.  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.
The morphology and infraciliature of four marine cyrtophorid ciliates isolated from Qingdao, China, were investigated. Based on the present work and on previous data, improved diagnoses for three rarely known species are provided: (1) Mirodysteria decora; small-sized marine Mirodysteria about 35–60 × 25–35 μm in vivo, oval in outline; body surface with two or three conspicuous dorsal spines and one caudal spine; three right kineties, the rightmost one extending dorso-apically; left frontal kineties reduced, each consisting of three basal bodies only; podite subcaudally positioned; two ventrally located contractile vacuoles. (2) Dysteria legumen; body oval with two longitudinal grooves on different plates; six right kineties, the rightmost two of which extend dorso-apically; two left frontal kineties and two ventrally located contractile vacuoles. (3) Dysteria proraefrons; body about 60 × 35 μm in vivo; six right kineties, the two rightmost of which extend dorso-apically and the leftmost one is considerably shortened; three left frontal kineties; two ventrally located contractile vacuoles. A population of D. derouxi with eight or nine right kineties is also briefly described. The current investigation further demonstrates high diversity and cosmopolitan distribution of this highly specialized group of benthic ciliates.  相似文献   

11.
A new halacarid species, Halacarellus fontinalis n. sp., from a spring in the Gesäuse National Park, Austria is described. The species is characterized by three pairs of large, equal-sized acetabula and slender claws and is expected to have evolved in the Tertiary from a Tethyan-Paratethyan Halacarellus species. CaspihalacarusViets, 1928, with a single species, C. hyrcanusViets, 1928, has large and external acetabula similar to those in H. fontinalis. Caspihalacarus is synonymized with Halacarellus.  相似文献   

12.
Research into spatial and temporal variation in seston transport was carried out during the year 2000 on three reaches on the longitudinal profile of the karstic cascading system of the Plitvice Lakes in Croatia. The three investigated reaches were (i) a channel over a barrier with low gradient; (ii) flow through a deep lake; and (iii) a channel with cascades and a steep gradient. The aim of the study was to establish the influence of physiographical and hydrological differences of these reaches on the quality and quantity of seston transport and food resources in the seston. To calculate the seston transport, we measured: total suspended matter (TSM), particulate inorganic matter (PIM), particulate organic matter (POM), chlorophyll-a (chl-a), heterotrophic bacteria and discharge. The PIM contribution from TSM ranged between 60 and 90%, while the percentage of POM in TSM was the highest in summer and ranged from 33 to 46%. POM and discharge were significantly negatively correlated (r = −0.43, P < 0.05). For the transport of TSM, PIM, POM and chlorophyll-a statistically significant differences between the three reaches were established. In a principal component analysis, 86% of the variance was explained by the first two factors. The first factor corresponded well with net transport of TSM, PIM, POM and chl-a and distinguished investigated reaches in two groups: the 1st group with increasing (reaches with low gradient and with high gradient), and the 2nd group with decreasing net seston transport (reach with flow through a deep lake). The second factor corresponded strongly with discharge and distinguished investigated reaches according to their temporal variability. Electronic Supplementary Material Supplementary material is available in the online version of this article at and is accessible for authorized users Handling editor: J. Padisak  相似文献   

13.
A new genus and a new species of Canthocamptidae: Maraenobiotus canadensis and Neomaraenobiotus laurentiacus (Copepoda: Harpacticoida) are described and their taxonomic relationships are discussed. They have been collected from wet mosses in Northern Canada.  相似文献   

14.
A new type of exterilium larvae referable to Leptobrotula (Ophidiiformes: Ophidiidae) is described on the basis of two specimens (20.7+mm and ca. 35.4mmSL) collected from the tropical Indo-Pacific. They are characterized, in particular, by several elongated anterior dorsal fin rays supported by the large dorsal pterygiophores and the exterilium gut bearing filamentous appendages along the ventral border. It is suggested from larval evidence that Leptobrotula forms a distinct lineage with Brotulotaenia and Lamprogrammus, which may be placed in an expanded Brotulonaeniinae.  相似文献   

15.
The species Balantidium coli is the only ciliate that parasitizes humans. It has been described in other primates, and it has been proposed that the species B. suis from pigs and B. struthionis from ostriches are synonyms of B. coli. Previous genetic analysis of pig and ostrich Balantidium isolates found a genetic polymorphism in the ITS region but its taxonomic relevance was not established. We have extended the genetic analysis to Balantidium isolates of pig, gorilla, human and ostrich origin. We have PCR-amplified and sequenced the ITS region of individual Balantidium cells. The predicted ITS secondary structures of the sequences obtained were transferred by homology modelling to the sequences of other Trichostomatia ciliates (Isotricha, Troglodytella, Lacrymaria and Spathidium) and compared to determine the importance of the differences in the primary sequences. The results show that the ITS2 secondary structure of the species considered follows the general pattern of other ciliates, although with some deviations. There are at least two main types of ITS sequence variants in B. coli which could be present in the same cell and they are common to the mammal and avian hosts studied. These data do not support B. suis and B. struthionis as distinct species.  相似文献   

16.
During a survey of bryophilous fungi from boreal and montane habitats in central Alberta, a hitherto undescribed species of Cladophialophora was recovered from Polytrichum juniperinum, Aulacomnium palustre, and Sphagnum fuscum. On potato dextrose agar (PDA) colonies grew slowly, attaining a diameter of 25 mm after 30 d, were dark grey, velvety, radially sulcate, and convolute and cracked at the centre. Micronematous conidiophores gave rise to branched chains of small (1–2 × 8–22 μm), cylindrical to fusiform conidia with truncate, swollen scars at each end. Phylogenies built on the ITS and ribosomal SSU regions indicate the isolates form a monophyletic clade within the family Herpotrichiellaceae (Chaetothyriales) that is composed of two geographically based groups, each with 99 % within-group sequence similarity and 97–98 % between-group sequence similarity. A teleomorph has not been found but would likely be similar to species of Capronia. In vitro inoculation of the isolates onto axenically grown P. juniperinum produced no discernible host symptoms, and host penetration could not be detected using light microscopy. The production of polyphenol oxidases by the fungus and the role of other Cladophialophora species as latent endophytes and saprobes suggest that a potential role for the fungus is the degradation of the polyphenol-rich cell walls of mosses. A dichotomous key to species of the genus Cladophialophora is provided.  相似文献   

17.
The single cell gel eletrophoresis or the comet assay was established in the freshwater snail Biomphalaria glabrata. For detecting DNA damage in circulating hemocytes, adult snails were irradiated with single doses of 2.5, 5, 10 and 20 Gy of 60Co gamma radiation. Genotoxic effect of ionizing radiation was detected at all doses as a dose-related increase in DNA migration. Comet assay in B. glabrata demonstrated to be a simple, fast and reliable tool in the evaluation of genotoxic effects of environmental mutagens.  相似文献   

18.
We performed a comparative morphological and molecular study on oxytrichid and urostylid stichotrichs (=part of the former hypotrichs). Included are new small subunit (18S) ribosomal RNA (rRNA) gene sequences from five rare oxytrichids (Gonostomum namibiense, Cyrtohymena citrina, Hemiurosoma terricola, Onychodromopsis flexilis, Orthoamphisiella breviseries) and published sequences, based on cultures provided by the senior author, of two key stichotrichid genera, viz., Gastrostyla and Engelmanniella. These and other sequences, altogether 27 species representing 23 genera, were used to analyze how 18S rRNA-based phylogenetic trees can be reconciled with the morphological and ontogenetical data. In 18S rRNA trees, the oligotrichine family Halteriidae invariably clusters within the oxytrichid clade, usually near Oxytricha granulifera, type species of the genus. This position is hardly supported by morphological and ecological evidence and, especially, it contradicts the current ontogenetic findings; possibly, it is an artifact caused by taxa undersampling and/or special molecular evolutionary events. In contrast, most morphological and DNA sequence data of the stichotrichs can be harmonized with the CEUU (Convergent Evolution of Urostylids and Uroleptids) hypothesis which suggests that the urostylid midventral pattern evolved from an oxytrichine ancestor, developing a second time within the Oxytrichidae. The systematic position of one of the two key genera could be clarified with the 18S rRNA sequences: Gastrostyla is a stylonychine oxytrichid. Based on the molecular data and a reassessment of ontogenesis, a new genus, Styxophrya nov. gen., is established for Onychodromus quadricornutus Foissner, Schlegel & Prescott, 1987.  相似文献   

19.
记述我国虱矮螨属Pediculaster Vitzthum1新种:开阳虱矮螨P.kaiyangensis Guo&Zhao sp.nov.,模式标本采自贵州省贵阳市开阳县中药店的远志Polygala tenuifolia Willd内,保存于贵州大学农学院昆虫研究所。  相似文献   

20.
Two new species of hyalellid amphipods, Hyalella crawfordi and H. gauthieri, are described from Lake Titicaca; H. echinus (Faxon, 1876) is redescribed. The H. echinus group of species is newly proposed for these three species, and a group diagnosis is provided. A key to the three species in the group is provided Full article published online at http://www.senckenberg.de/odes/06-10.htm.  相似文献   

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