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1.
Five Ceramiaceae (Rhodophyta) are reported from the offshore waters of the southeastern, warm temperate coast of the United States. These include two new monotypic genera, Calliclavula trifurcate Schneider in the Griffithsieae and Nwynea grandispora Searles in the Sphondylothamnieae, and three new species, Callithamniella silvae Searles, Ptilothamnion occidentale Searles, and Lejolisia exposita Schneider et Searles.  相似文献   

2.
We examined the molecular phylogeny and ultrastructure of Chlorogonium and related species to establish the natural taxonomy at the generic level. Phylogenetic analyses of 18S rRNA and RUBISCO LSU (rbcL) gene sequences revealed two separate clades of Chlorogonium from which Chlorogonium (Cg.) fusiforme Matv. was robustly separated. One clade comprised Cg. neglectum Pascher and Cg. kasakii Nozaki, whereas the other clade included the type species Cg. euchlorum (Ehrenb.) Ehrenb., Cg. elongatum (P. A. Dang.) Francé, and Cg. capillatum Nozaki, M. Watanabe et Aizawa. On the basis of unique ultrastructural characteristics, we described Gungnir Nakada gen. nov. comprising three species: G. neglectum (Pascher) Nakada comb. nov., G. mantoniae (H. Ettl) Nakada comb. nov., and G. kasakii (Nozaki) Nakada comb. nov. We also emended Chlorogonium as a monophyletic genus composed of Cg. euchlorum, Cg. elongatum, and Cg. capillatum. Because Cg. fusiforme was distinguished from the redefined Chlorogonium and Gungnir by the structure of its starch plate, which is associated with pyrenoids, we reclassified this species as Rusalka fusiformis (Matv.) Nakada gen. et comb. nov.  相似文献   

3.
On the basis of LM, we isolated strains of two species of fusiform green flagellates that could be assigned to former Chlorogonium (Cg.) Ehrenb. One species, “Cg.”heimii Bourr., lacked a pyrenoid in its vegetative cells and required organic compounds for growth. The other was similar to Cg. elongatum (P. A. Dang.) Francé and “Cg.”acus Nayal, but with slightly smaller vegetative cells. Their molecular phylogeny was also studied based on combined 18S rRNA, RUBISCO LSU (rbcL), and P700 chl a‐apoprotein A2 (psaB) gene sequences. Both species were separated from Chlorogonium emend., Gungnir Nakada and Rusalka Nakada, which were formerly assigned to Chlorogonium. They were accordingly assigned to new genera, Tabris Nakada gen. nov. and Hamakko (Hk.) Nakada gen. nov. as T. heimii (Bourr.) Nakada comb. nov. and Hk. caudatus Nakada sp. nov., respectively. Tabris is differentiated from other genera of fusiform green flagellates by its vegetative cells, which only have two apical contractile vacuoles and lack a pyrenoid in the chloroplast. Hamakko, on the other hand, is distinguishable by the fact that its pyrenoids in vegetative cells are penetrated by flattened thylakoid lamellae.  相似文献   

4.
Asteromenia gen. nov. (Rhodymeniales, Rhodophyta) is proposed with a single species, Asteromenia peltata (W. R. Taylor) comb. nov. (basionym: Fauchea peltata W. R. Taylor). Thalli of the proposed new genus are stipitate with dorsiventral, peltate blades that are initially circular in shape but with age become stellate with ligulate arms. Internally, the blades have a polystromatic medulla of large, hyaline cells, grading into a cortex of smaller, pigmented cells. Clusters of translucent cells occur on the dorsal surface of the blade. Tetrasporangia are formed by transformations of intercalary midcortical cells. Mature tetrasporangia have cruciately arranged spores and are densely aggregated in the cortex, mostly on the ventral surface, but occasional tetrasporangia also arise on the dorsal surface. Carpogonial branches are four-celled and arise on inner cortical cells. Auxiliary cells are borne on auxiliary mother cells attached to supporting cells of the carpogonial branches. Cystocarps are protuberant, with well-developed, ostiolate pericarps that often have extended, proboscis-like necks. The new genus differs from the previously described peltate or dorsiventral taxa in the Rhodymeniaceae by its polystromatic medulla (Maripelta and Sciadophycus have a monostromatic medulla), intercalary tetrasporangia formed in an unmodified cortex, and four-celled carpogonial branches (Halichrysis, as typified by H. depressa (J. Agardh) F. Schmitz, has terminal tetrasporangia in nemathecia and three-celled carpogonial branches).  相似文献   

5.
The tiny jumping flagellate originally described as Pedinomonas mikron Throndsen was isolated into pure culture from Australian waters and its ultrastructure critically examined. Pedinomonas mikron differs in behavior and in features of the flagellar apparatus from P. minor, the type species from freshwater, and is referred to the new genus Resultor. The two genera are closely related and form the new class Pedinophyceae, which is characterized by features of the flagellar apparatus, mitosis, and cytokinesis. The flagella show the 11/5 orientation otherwise characteristic of Ulvophyceae and Pleurastrophyceae, but they are arranged end to end as in the Chlorophyceae. The flagellar root system is asymmetric and includes a rhizoplast that emerges from the base of one flagellum but subsequently associates with a microtubular root from the second basal body. Mitosis studied previously by Pickett-Heaps and Ott in Pedinomonas is closed, unlike in other green algae, and the spindle is persistent. No phycoplast or phragmoplast is formed during cytokinesis. The eyespot of the Pedinophyceae is located at the opposite end of the cell from the flagella and adjacent to the pyrenoid, as in the most primitive members of the Prasinophyceae. Members of the Pedinophyceae lack prasinoxanthin and Mg 2,4D, characteristic of certain other primitive green algae. The primitive green algae include the classes Prasinophyceae and Pedinophyceae. Micromonadophyceae Mattox et Stewart is considered a synonym of Prasinophyceae. Two new orders are established, Pedinomonadales, containing all known members of the Pedinophyceae, and Scourfieldiales, with the single family Scourfieldiaceae fam. nov. and the single genus Scourfieldia.  相似文献   

6.
The newly described toxic dinoflagellate Pfiesteria piscicida is a polymorphic and multiphasic species with flagellated, amoeboid, and cyst stages. The species is structurally a heterotroph; however, the flagellated stages can have cleptochloroplasts in large food vacuoles and can temporarily function as mixotrophs. The flagellated stage has a typical mesokaryotic nucleus, and the theca is composed of four membranes, two of which are vesicular and contain thin plates arranged in a Kofoidian series of Po, cp, X, 4′, 1a, 5″, 6c, 4s, 5″′, and 2″″. The plate tabulation is unlike that of any other armored dinoflagellate. Nodules often demark the suture lines underneath the outer membrane, but fixation protocols can influence the detection of plates. Amoeboid benthic stages can be filose to lobose, are thecate, and have a reticulate or spiculate appearance. Amoeboid stages have a eukaryotic nuclear profile and are phagocytic. Cyst stages include a small spherical stage with a honeycomb, reticulate surface and possibly another stage that is elongate and oval to spherical with chrysophyte-like scales that can have long bracts. The species is placed in a new family, Pfiesteriaceae, and the order Dinamoebales is emended.  相似文献   

7.
云南省蚱科一新属新种(直翅目:蚱科)   总被引:4,自引:0,他引:4  
本文报道蚱科一新属一新种。新属,微翅蚱属Alulatettix gen nov.的主要特征是前胸背板强烈隆起呈屋脊形,前胸背板侧片后缘具二凹陷,前、后翅甚微小。其模式种为云南微翅蚱Alulatettix yunnanensis sp.nov.  相似文献   

8.
The new genus Pycnococcus Guillard is based on several clones from the western North Atlantic and Gulf of Mexico. The type and only described species, Pycnococcus provasolii Guillard, sp. nov., is typified by clone Ω48-23 from the North Atlantic. Cells of Pycnococcus provasolii are solitary, spherical, 1.5–4.0 μm in diameter, have a resistant cell wall lacking sporopollenin, and have the ultrastructural characteristics of green algae. With the light microscope they are scarcely distinguishable from cells of other coccoid planktonic organisms. In pigmentation P. provasolii resembles Micromonas pusilla, Mantoniella squamata, and Mamiella gilva in having chl a, much chl b, Mg 2,4-divinylphaeoporphyrin a5 monomethyl ester (presumably), and prasinoxanthin as a major xanthophyll. The pyrenoid of P. provasolii has a cytoplasmic channel, which is unique among species closely related to it. Flagellates, occurring rarely in culture, are similar to but distinguishable from known Pedinomonas species by size and shape. Pycnococcus provasolii is referred to the new family Pycnococcaceae Guillard, in the order Mamiellales of the class Micromonadophyceae (Chlorophyta). Clones of Pycnococcus provasolii are oceanic in nutritional characteristics, require only vitamin B12 in culture, and are well adapted to growth under blue or blue-violet light of low intensity.  相似文献   

9.
Two new propagule-farming red algae from southern Australia, Deucalion levringii (Lindauer) gen. et comb. nov. and Anisoschizus propaguli gen. et sp. nov., are described and defined largely on their development in laboratory culture. Deucalion is included in the tribe Compsothamnieae on the basis of its subapical procarp and alternate distichous branching. It differs from the other genera included in that tribe in that it produces 3-celled propagules, polysporangia, a subapical cell of the fertile axis which bears 3 pericentral cells, and an apparently post-fertilization involucre which develops from the hypogenous and sub-hypogenous cells of the fertile axis. Its gametophyte morphology has been elucidated in culture, as only sporophytes are known from the field. Gametophytes do not appear to produce propagules. Anisoschizus is provisionally included in the tribe Spermothamnieae on the basis of its subdichotomous branching, possession of a prostrate system and the production of polysporangia. It differs from the other genera of the tribe in the production of 2-celled propagules. Observations on the germination of the “monosporangia” of Mazoyerella arachnoidea and Monosporus spp. indicate that they are analagous to the propagules of Deucalion and Anisoschizus. The nature of these propagules and their role in recycling the parent plant are discussed and contrasted with true monosporangia. It is recommended that Monosporus be maintained as a form genus containing representatives from more than one tribe, as exemplified by plants from Lord Howe I. provisionally identified as M. indicus Boergesen which have both prostrate and erect, as opposed to only erect, axes.  相似文献   

10.
Cyrtophorids are a specialized group of ciliated protozoa with multitudinous morphotypes. In the present work, the morphology and infraciliature of two new and three rarely known species, including two new genera of cyrtophorid ciliates, Heterohartmannula fangi gen. et sp. nov. , Aporthotrochilia pulex (Deroux, 1976) gen. et comb. nov. , Trochilia alveolata sp. nov. , Trochochilodon flavus Deroux, 1976, and Hypocoma acinetarum Collin, 1907, are described. Heterohartmannula gen. nov. is mainly characterized by a combination of features: two circumoral kineties obliquely arranged, podite not surrounded by somatic kineties, and no distinct gap between left and right ciliary field. Aporthotrochilia gen. nov. is diagnosed mainly by: podite present, oral ciliature reduced to two fragments, several kinety fragments positioned on the right posterior of frontoventral kineties and several terminal fragments. Phylogenetic analyses based on the small subunit rRNA (SSU rRNA) gene sequences support the establishment of two new genera and indicate that Heterohartmannula is most closely related to Hartmannula, and Aporthotrochilia is basal to the Cyrtophoria‐Chonotrichia clade. Trochilia alveolata sp. nov. differs from its congeners mainly by having a conspicuous alveolar layer. In addition, detailed live and infraciliature data of Hypocoma acinetarum and Trochochilodon flavus are supplied. © 2012 The Linnean Society of London, Zoological Journal of the Linnean Society, 2012, 164 , 1–17.  相似文献   

11.
A new species from the diatom genus Gomphoneis, G. mesta, was described following morphological and ultra-structural analyses of its frustules by light and scanning electron microscopy. The valve striation consisting of double rows of areolae and the presence of longitudinal lines dictate the systematic position of this taxon in the genus Gomphoneis. The set of features that distinguishes G. mesta from allied taxa is small valves, 26.5–81.6 μm in length and 7–12.5 μm in width, lanceolate to clavate shape, with a broadly lanceolate axial area, and longitudinal lines positioned next to the valve margins, thus contributing to a general thickening of the valve outline. When compared to other members of the genus, G. mesta most resembles G. magna Kociolek & Stoermer. Gomphoneis mesta dominates the epilithic community, growing in the Cherna Mesta, a pristine high-mountainous tributary of the Mesta River in Bulgaria. The species has been also found as small populations in all other benthic habitats of the Cherna Mesta and in a few locations along the Mesta River.  相似文献   

12.
Bipolar asymmetry has been considered a morphological characteristic sufficient for differentiation of genera among the Desmidiaceae. Therefore, Micrasterias sudanensis Grönbl., Prowse & Scott, the only species of Micrasterias showing such asymmetry, is made the type of a new genus, Prescottiella, gen. nov.  相似文献   

13.
Some Liagora and Izziella distributed in Taiwan display a wide range of morphological variation and can be difficult to distinguish. To clarify species concepts, we applied DNA sequence analyses and examined carposporophyte development in detail. These studies revealed two new species, which are described herein as Izziella hommersandii sp. nov. and Izziella kuroshioensis sp. nov. I. kuroshioensis superficially resembles Izziella formosana and Izziella orientalis in that its involucral filaments subtend rather than surround the lower portion of the gonimoblast mass (= Izziella type) and a fusion cell is formed from cells of the carpogonial branch, but it can be separated by differences in the cell numbers and branching pattern of the involucral filaments, as well as thallus morphology. In contrast to other species that also bear short lateral branchlets, I. hommersandii is unique in possessing a mixture of short and long involucral filaments, a phenomenon not reported before. The length of the involucral filaments is species specific among species of Izziella and contrasts to the behavior of the involucral filaments after fertilization in species such as “Liagorasetchellii [= Titanophycus setchellii comb. nov.], in which the filaments completely envelop the gonimoblast. In addition, the cells of the carpogonial branch in Titanophycus do not fuse after fertilization to form a fusion cell. Thus, a combination of characters with respect to the behavior of the carpogonial branch and the involucral filaments after fertilization is very useful for delineating species boundaries in Izziella and for separating Titanophycus from Izziella and Liagora.  相似文献   

14.
A new ceramiaceous alga, Sciurothamnion stegengae De Clerck et Kraft, gen. et sp. nov., is described from the western Indian Ocean and the Philippines. Sciurothamnion appears related to the tribe Callithamnieae on the basis of the position and composition of its procarps and by the majority of post‐fertilization events. It differs, however, from all current members of the tribe by the presence of two periaxial cells bearing determinate laterals per axial cell. Additionally, unlike any present representative of the subfamily Callithamnioideae, no intercalary foot cell is formed after diploidization of the paired auxiliary cells. The genus is characterized by a terminal foot cell (“disposal cell”), which segregates the haploid nuclei of the diploidized auxiliary cell from the diploid zygote nucleus. The nature of three types of foot cells reported in the Ceramiaceae (intercalary foot cells containing only haploid nuclei, intercalary foot cells containing haploid nuclei and a diploid nucleus, and terminal foot cells containing only haploid nuclei) is discussed.  相似文献   

15.
A new raphidophyte flagellate is described from the river mouth of the Daintree River, north-east Australia where there are extensive mangrove forests. The organism has two distinct phases: a club-shaped motile form, and a more or less spherical benthic non-motile form. The motile cell is metabolic and possesses 10–20 chloroplasts. The chloroplasts are imbricated, somewhat reminiscent of roofing tiles. A unique structure has been found at the posterior end of the cell. It is a tubular invagination, which consists of a single membrane supported by many small flattened vesicles. In addition, the structure is surrounded by many fibril-containing vesicles. The tubular invagination is different from both the contractile vacuoles and the pusules of dinoflagellates in both behavior and structure. Based on the possession of these unique features, it is concluded that the this mangrove flagellate should be described as a new species in a new genus and the name Haramonas dimorpha Horiguchi gen. et sp. nov. is proposed.  相似文献   

16.
17.
Morphological and anatomical evidence is presented to support the taxonomic judgment that Talarodictyon tilesii Endlicher is conspecific with Hydroclathrus stephanosorus Kraft in Kraft & Abbott. Because the former name has nomenclatural priority over the latter name, Hydroclathrus tilesii (Endlicher) comb. nov. is proposed.  相似文献   

18.
We investigate an organism that closely resembles the nonphotosynthetic dinoflagellate “Gymnodinium elongatum” Hope 1954 using EM and molecular methods. Cells are 20–35 μm long, 10 μm wide, biconical, transparent, and have a faint broad girdle. Thecal plates are thin but present (plate formula Po Pi CP 3′ 1–2A 5″ 3C 6S 4? 3″″). With the exception of one feature, the presence of three antapical plates, the amphiesmal arrangement of this species is consistent with that of the order Peridiniales, family Podolampaceae; it is not at all consistent with the characteristics of the genus Gymnodinium. On the basis of these ultrastructural findings, we establish a new genus, Lessardia, and a new species, Lessardia elongata Saldarriaga et Taylor. Molecular phylogenetic analyses were performed using the small subunit rRNA genes of L. elongata as well as Roscoffia capitata, a member of a genus of uncertain systematic position that has been postulated to be related to the Podolampaceae. These analyses place Lessardia and Roscoffia as sister lineages within the so‐called GPP complex. Thecal plate arrangements led us to expand the family Podolampaceae to include the genus Lessardia and, in combination with new molecular results, to propose a close relationship between the Podolampaceae and Roscoffia. Within this lineage, Lessardia and Roscoffia appear to have retained a number of ancestral characters: Roscoffia still has a well‐developed cingulum, a feature absent in all members of the Podolampaceae, and Lessardia has more than one antapical plate, a character reminiscent of some members of the family Protoperidiniaceae.  相似文献   

19.
20.
华模蛛科——采自中国的蜘蛛目一新科(蛛形纲,蜘蛛目)   总被引:1,自引:0,他引:1  
记述了采自我国云南西双版纳雨林的1新科,华模蛛科Sinopimoidae fam.nov.,1新属,华模蛛属Sinopimoa gen.nov.,1新种,双色华模蛛Sinopimoa bicolor sp.nov..模式标本保存在中国科学院动物研究所.  相似文献   

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