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1.
Since 1998, a heterokont flagellate initially named Chattonella aff. verruculosa has formed recurrent extensive blooms in the North Sea and the Skagerrak, causing fish mortalities. Cells were isolated from the 2001 bloom off the south coast of Norway, and monoalgal cultures were established and compared with the Chattonella verruculosa Y. Hara et Chihara reference strain NIES 670 from Japan. The cells in Norwegian cultured isolates were very variable in size and form, being large oblong (up to 34 μm long) to small rounded (5–9 μm in diameter) with two unequal flagella, numerous chloroplasts, and mucocysts. The SSU and partial LSU rDNA sequences of strains from Norway and Japan were compared and differed by 0.4% (SSU) and 1.3% (LSU), respectively. Five strains from Norway were identical in the LSU rDNA region. Phylogenetic analyses based on heterokont SSU and concatenated SSU + LSU rDNA sequences placed C. aff. verruculosa and the Japanese C. verruculosa within the clade of Dictyochophyceae, with the picoflagellate Florenciella parvula Eikrem as the closest relative. Ultrastructure, morphology, and pigment composition supported this affinity. We propose the name Verrucophora farcimen sp. et gen. nov. for this flagellate and systematically place it within the class Dictyochophyceae. Our studies also show that C. verruculosa from Japan is genetically and morphologically different but closely related to V. farcimen. The species is transferred from the class Raphidophyceae to the class Dictyochophyceae and renamed Verrucophora verruculosa. We propose a new order, Florenciellales, to accommodate V. farcimen, V. verruculosa, and F. parvula.  相似文献   

2.
A new chlorarachniophytan alga, Gymnochlora stellata Ishida et Y. Hara gen. et sp. nov., has been isolated from Anae Island in Guam. It is a green, star-shaped, unicellular, amoeboid organism with several filopodia that do not form a reticulopodial network. Neither zoospores nor walled coccoid cells have been observed throughout the life cycle. The chloroplast ultrastructure is similar to those of described species; however, the pyrenoid matrix, which is invaded by many tubular structures originating from the inner membrane of the chloroplast envelope, is unique. A classification system is proposed for the Chlorarachniophyta. In this system, the ultrastructural features of the pyrenoid and the location of the nucleomorph in the periplastidial compartment are used as generic criteria, while the morphological features of the vegetative cells and life cycle patterns are used for species criteria. The described species, except for Cryptochlora perforans Calderon-Saenz et Schnetter, are also reassessed under the new system, and consequent nomenclatural requirements for the genus Chlorarachnion are dealt with in this paper. The taxonomic rank of a previously described species, Chlorarachnion globosum Ishida et Y. Hara, is elevated and Lotharella globosa (Ishida et Y. Hara) Ishida et Y. Hara gen. nov. et comb. nov. is proposed.  相似文献   

3.
Species within the class Raphidophyceae were associated with fish kill events in Japanese, European, Canadian, and U.S. coastal waters. Fish mortality was attributable to gill damage with exposure to reactive oxygen species (peroxide, superoxide, and hydroxide radicals), neurotoxins, physical clogging, and hemolytic substances. Morphological identification of these organisms in environmental water samples is difficult, particularly when fixatives are used. Because of this difficulty and the continued global emergence of these species in coastal estuarine waters, we initiated the development and validation of a suite of real‐time polymerase chain reaction (PCR) assays. Sequencing was used to generate complete data sets for nuclear encoded small‐subunit ribosomal RNA (SSU rRNA; 18S); internal transcribed spacers 1 and 2, 5.8S; and plastid encoded SSU rRNA (16S) for confirmed raphidophyte cultures from various geographic locations. Sequences for several Chattonella species (C. antiqua, C. marina, C. ovata, C. subsalsa, and C. verruculosa), Heterosigma akashiwo, and Fibrocapsa japonica were generated and used to design rapid and specific PCR assays for several species including C. verruculosa Hara et Chihara, C. subsalsa Biecheler, the complex comprised of C. marina Hara et Chihara, C. antiqua Ono and C. ovata, H. akashiwo Ono, and F. japonica Toriumi et Takano using appropriate loci. With this comprehensive data set, we were also able to perform phylogenetic analyses to determine the relationship between these species.  相似文献   

4.
The ultrastructure, morphology and life cycle of a new chlorarachniophyte alga collected from Okinawa in Japan have been studied. The life cycle of this alga consists of amoeboid, wall‐less round, coccoid and flagellated cells in culture condition; however, the coccoid and flagellate cells are very rare. The pyrenoid ultra‐structure of this alga is the same as that of a previously described species, Lotharella globosa. Since pyrenoid ultrastructure has been adopted as the main criterion for the generic classification of the chlorarachniophytes, the present alga is placed in Lotharella. However, the present alga has a dominant amoeboid cell stage and a reduced walled‐cell stage in the life cycle, while in L. globosa, the walled‐cell stage is dominant and there is no amoeboid cell stage. Therefore the present alga is described as a new species of Lotharella: Lotharella amoeboformis Ishida et Y. Hara sp. nov.  相似文献   

5.
Impatiens quadriloba K. M. Liu et Y. L. Xiang sp. nov. collected from the Siguniang Mountains Nature Reserve in northwestern Sichuan, China, is described and illustrated. The seed‐coat and pollen morphology of the new species are described and diagnostic morphological characters that distinguish the new species from the related I. falcifer Hook. f. are discussed.  相似文献   

6.
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   

7.
Cysts of a chain‐forming dinoflagellate Gyrodinium impudicum Fraga et Bravo (Gymnodiniales) were found in surface sediments of Harima‐Nada and Nakaumi, western Japan. The detailed morphology of living and empty cysts is described. The living cysts are roundish to ellipsoidal in polar view, and hemispherical in lateral view. Among three empty cysts obtained, two different archeopyles were observed; either a long slit with an operculum, or a hole with irregular zigzag outline. The living cysts of Gyro. impudicum are morphologically similar to those of the genus Chattonella antiqua (Hada) Ono and Chattonella marina (Subrahmanyan) Y. Hara et Chihara (Raphidophyceae), except cyst color and contents. The living cysts of Gyro. impudicum were rarely encountered, and their density was always less than 1 cell in 1 cm?3 in the present samples.  相似文献   

8.
9.
A new species of Rhaponticoides Vaill., Rhaponticoidesaytachii Y. Ba?c?, Do?u & Dinç sp. nov. collected by the authors from south Anatolia, is described and illustrated. The new species is restricted to deprived Quercus forest openness around Dumlugöze‐Sar?veliler (C4 Karaman). Diagnostic morphological characters from R. amplifolia (Boiss. & Heldr.) M.V. Agab. & Greuter are discussed. The ecology, biogeography and conservation status of the new species is also presented.  相似文献   

10.
Sulcochrysis biplastida gen. et sp. nov., a golden, marine, mixotrophic flagellate is described. Cells resemble Ochromonas in light microscopic features, but they are distinct at the electron microscopic level from Ochromonas or any other typical chrysophyte. Ultrastructural features that discriminate Sulcochrysis from the Chrysophyceae are: (i) a proximal helix in the flagellar transition region; (ii) basal bodies situated in the anterior depression of the nucleus; (iii) the lack of the rhizoplast; and (iv) simple flagellar hairs lacking lateral filaments. These features suggest that Sulcochrysis is a relative of the Pedinellophyceae, Dictyochophyceae and Pelagophyceae. However, Sulcochrysis has a flagellar root system similar to that of the Ochromonas-type cell and it may use the R3 root for prey capture, as do ochromonadalean algae. The R3 root and the phagotrophic mechanism using the R3 root are interpreted as a plesiomorphy, because these are also distributed in primitive heterokonts such as the bicosoecids. Sulcochrysis has one microtubule probably homologous with the x-fibre of Bicosoeca maris Picken. Based on these features it is suggested that Sulcochrysis is an organism that links bicosoecids (Bicosoeco-phyceae), Pedinellophyceae, Dictyochophyceae and Pelagophyceae.  相似文献   

11.
Cellular morphology and the phylogenetic position of a new unarmored photosynthetic dinoflagellate Cochlodinium fulvescens Iwataki, Kawami et Matsuoka sp. nov. were examined by light microscopy and molecular phylogenetic analyses based on partial large subunit ribosomal DNA (LSU rDNA) and small subunit ribosomal DNA (SSU rDNA) sequences. The cells of C. fulvescens closely resemble C. polykrikoides, one of the most harmful red tide forming dinoflagellates, due to it possessing a cingulum encircling the cell approximately twice, a spherical nucleus positioned in the anterior part of the cell and an eyespot‐like orange pigmented body located in the dorsal side of the epicone, as well as formation of cell‐chains. However, this species is clearly distinguished from C. polykrikoides based on several morphological characteristics, namely, cell size, shape of chloroplasts and the position of narrow sulcus situated in the cell surface. The sulcus of C. fulvescens is located at the intermediate position of the cingulum in the dorsal side, whereas that of C. polykrikoides is situated immediately beneath the cingulum. LSU rDNA phylogenies indicated that C. fulvescens is clearly distinct from, but closely related to C. polykrikoides among dinoflagellates.  相似文献   

12.
A new genus of sand‐dwelling photosynthetic dinoflagellate, Testudodinium Horiguchi, Tamura, Katsumata et A. Yamaguchi is proposed based on Testudodinium testudo (Herdman) Horiguchi, Tamura, Katsumata, et A. Yamaguchi comb. nov. (Basionym: Amphidinium testudo Herdman) and a new species in this new genus, Testudodinium maedaense Katsumata et Horiguchi sp. nov. is described. Amphidinium corrugatum is also transferred to this genus, making a new combination T. corrugatum (Larsen et Patterson) Horiguchi, Tamura et A. Yamaguchi. These three species are similar to the members of the genus Amphidinium in having an extremely small episome and a dorsoventrally flattened cell body. They are, however, distinguished from the genus Amphidinium seusu stricto by the possession of a distinct longitudinal furrow in the middle of ventral side of the episome. Phylogenetic trees based on small subunit (SSU) rDNA revealed that all three of these Testudodinium species formed a robust clade and, although statistical support is not high, the tree suggests Testudodinium clade is not closely related to Amphidinium seusu stricto clade. The morphological differences together with molecular data support the establishment of a new genus for A. testudo and its related species.  相似文献   

13.
Raphidophytes (class Raphidophyceae) produce high levels of reactive oxygen species (ROS), yet little is known regarding cellular scavenging mechanisms needed for protection against these radicals. Enzymatic activities of the antioxidants superoxide dismutase (SOD) and catalase (CAT) were measured in conjunction with the production of superoxide (O2??) and hydrogen peroxide (H2O2) in batch cultures of five different raphidophytes species during early exponential, late‐exponential, and stationary growth phases. The greatest concentrations of O2?? per cell were detected during exponential growth with reduced levels in stationary phases in raphidophytes Heterosigma akashiwo (Hada) Hada ex Y. Hara et Chihara, Chattonella marina (Subrahman.) Y. Hara et Chihara, and Chattonella antiqua (Hada) Ono (strain 18). Decreasing trends from exponential to stationary phases for SOD activity and H2O2 per cell were observed in all species tested. Significant correlations between O2?? per cell and SOD activity per cell over growth phase were only observed in three raphidophytes (Heterosigma akashiwo, Chattonella marina, and Chattonella antiqua strain 18), likely due to different cellular locations of externally released O2?? radicals and intracellular SOD enzymes measured in this study. CAT activity was greatest at early exponential phase for several raphidophytes, but correlations between H2O2 per cell and CAT activity per cell were only observed for Fibrocapsa japonica Toriumi et Takano, Chattonella antiqua (strain 18), and Chattonella subsalsa Biecheler. Our results suggest that SOD and CAT play important protective roles against ROS during exponential growth of several raphidophytes, while other antioxidant pathways may play a larger role for scavenging ROS during later growth.  相似文献   

14.
Significant production of superoxide, a known reductant of both inorganic and organically complexed iron(III), occurs in natural systems by both biotic and abiotic pathways. We have investigated the generation of superoxide by Chattonella marina (Subrahman.) Y. Hara et Chihara, a phytoplankton taxon known to produce high levels of this reactive oxygen species, and examined the role of superoxide in the acquisition of iron by this organism. Additionally, a generalized model for iron acquisition by C. marina has been developed, which includes three pathways of iron acquisition from organically complexed iron(III): nondissociative reductive uptake, dissociative reductive uptake, and nonreductive dissociative uptake. The model is shown to be particularly useful in ascertaining the relative importance of these various iron‐uptake pathways as a function of solution parameters including concentration and iron‐binding strength of the organic ligand and superoxide concentration. Our results suggest that superoxide can participate in the C. marina iron‐uptake process when iron is complexed to weak ligands, such as citrate, but plays only a minor role when iron is bound to a strong ligand. It thus appears that facilitation of iron acquisition is not the sole purpose of superoxide production by these organisms.  相似文献   

15.
Ceropegia pullaiahii Kullayiswamy, Sandhyarani et Karuppusamy sp. nov. (Apocynaceae) is described from open dry deciduous forest of Anantapur district, Andhra Pradesh, India. Its tubers are eaten by the local people. It is similar to C. mahabalei Hemadri et Ansari but differs in its twining habit and 3‐flowered cyme.  相似文献   

16.
We have undertaken a comprehensive, molecular‐assisted alpha‐taxonomic examination of the rhodophyte family Liagoraceae sensu lato, a group that has not previously been targeted for molecular studies in the western Atlantic. Sequence data from three molecular markers indicate that in Bermuda alone there are 10 species in nine different genera. These include the addition of three genera to the flora — Hommersandiophycus, Trichogloeopsis, and Yamadaella. Liagora pectinata, a species with a type locality in Bermuda, is phylogenetically allied with Indo‐Pacific species of Hommersandiophycus, and the species historically reported as L. ceranoides for the islands is morphologically and genetically distinct from that taxon, and is herein described as L. nesophila sp. nov. Molecular sequence data have also uncovered the Indo‐Pacific L. mannarensis in Bermuda, a long‐distance new western Atlantic record. DNA sequences of Trichogloeopsis pedicellata from the type locality (Bahamas) match with local specimens demonstrating its presence in Bermuda. We described Yamadaella grassyi sp. nov. from Bermuda, a species phylogenetically and morphologically distinct from the generitype, Y. caenomyce of the Indo‐Pacific. Our data also indicated a single species each of Ganonema, Gloiocallis, Helminthocladia, Titanophycus, and Trichogloea in the flora.  相似文献   

17.
A multi‐gene (SSU, LSU, psbA, and COI) molecular phylogeny of the family Corallinaceae (excluding the subfamilies Lithophylloideae and Corallinoideae) showed a paraphyletic grouping of six monophyletic clades. Pneophyllum and Spongites were reassessed and recircumscribed using DNA sequence data integrated with morpho‐anatomical comparisons of type material and recently collected specimens. We propose Chamberlainoideae subfam. nov., including the type genus Chamberlainium gen. nov., with C. tumidum comb. nov. as the generitype, and Pneophyllum. Chamberlainium is established to include several taxa previously ascribed to Spongites, the generitype of which currently resides in Neogoniolithoideae. Additionally we propose two new genera, Dawsoniolithon gen. nov. (Metagoniolithoideae), with D. conicum comb. nov. as the generitype and Parvicellularium gen. nov. (subfamily incertae sedis), with P. leonardi sp. nov. as the generitype. Chamberlainoideae has no diagnostic morpho‐anatomical features that enable one to assign specimens to it without DNA sequence data, and it is the first subfamily to possess both Type 1 (Chamberlainium) and Type 2 (Pneophyllum) tetra/bisporangial conceptacle roof development. Two characters distinguish Chamberlainium from Spongites: tetra/biasporangial conceptacle chamber diameter (<300 μm in Chamberlainium vs. >300 μm in Spongites) and tetra/bisporangial conceptacle roof thickness (<8 cells in Chamberlainium vs. >8 cells in Spongites). Two characters also distinguish Pneophyllum from Dawsoniolithon: tetra/bisporangial conceptacle roof thickness (<8 cells in Pneophyllum vs. >8 cells in Dawsoniolithon) and thallus construction (dimerous in Pneophyllum vs. monomerous in Dawsoniolithon).  相似文献   

18.
In this study we investigated the morphology of three oligotrich (s.l.) ciliates, Strombidium guangdongense sp. nov., Cyrtostrombidium paralongisomum Tsai et al., 2015 and Strombidinopsis sinicum sp. nov. Strombidium guangdongense sp. nov. is characterized by its elongate obconical to obovoidal body shape and widely spaced dikinetids in the girdle and ventral kineties. Another new species, Strombidinopsis sinicum sp. nov. is diagnosed by its small size and semi-globular body shape without mineral envelopes. Some additional morphological data of the recently described species Cyrtostrombidium paralongisomum Tsai et al., 2015, such as the endoral membrane, are supplied based on our population. We also analysed the molecular phylogeny of each species based on small subunit rRNA (SSU rRNA) gene sequence data. The monophyly of Cyrtostrombidium is supported by our phylogenetic analyses, but the monophyly of Strombidinopsis and of the family Strombidinopsidae are both rejected by AU tests. In addition, Strombidium species have a tail branch separately from one another in phylogenetic trees, whereas strombidiids with a pigment spot group together, suggesting the latter character is a synapomorphy for this group of strombidiids.

http://zoobank.org/urn:lsid:zoobank.org:act:35FE2AFD-A582-4885-BD01-48901E4C76C4

http://zoobank.org/urn:lsid:zoobank.org:act:E9D4A497-DAD6-4AA0-A044-A5A1D2C1A057  相似文献   

19.
Two new taxa of Silene L. (Caryophyllaceae) from Turkey, Silene demirizii K. Y?ld?z & Ç?rp?c? sp. nov. and Silene marschallii C. A. Meyer subsp. anamasi K. Y?ld?z & Dadand? subsp. nov. are described and illustrated. Their taxonomic positions are discussed and they are compared with allied taxa. The distributions of the new and closely related species are mapped. Pollen grain and seed coat ultrastructure of the new and allied taxa were examined by SEM.  相似文献   

20.
Paracyathocaulis ogurae gen. et comb. nov. andCyathocaulis yezopteroides sp. nov. are Late Cretaceous tree-fern stems with cyatheaceous affinity. They are comparable with the Recent scaly cyatheoids (Cyathea s.l.), as well as with the Cretaceous and Tertiary fossil stems that have similar anatomy. All of these tree ferns, including the Late Jurassic to Early CretaceousOguracaulis Tidwellet al., comprise a well-defined morphological complex within Cyatheaceae, and are considered to be monophyletic. The taxonomy of this complex is analyzed cladistically, and the cladogram is phylogenetically evaluated by reference to the chronological data of fossils.  相似文献   

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