PFIESTERIA PISCICIDA GEN. ET SP. NOV. (PFIESTERIACEAE FAM. NOV.), A NEW TOXIC DINOFLAGELLATE WITH A COMPLEX LIFE CYCLE AND BEHAVIOR1

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.     

ULTRASTRUCTURE AND 18S RRNA GENE SEQUENCE FOR PELAGOMONAS CALCEOLATA GEN. ET SP. NOV. AND THE DESCRIPTION OF A NEW ALGAL CLASS,THE PELAGOPHYCEAE CLASSIS NOV.1

Pelagomonas calceolata gen. et sp. nov., an ultra-planktonic marine alga, is described using electron microscopy and the cytoplasmic small subunit (18S) ribosomal RNA (rRNA) gene sequence. Cells are uniflagellate, about 1.5 × 3 μm in size. The flagellium has two rows of bipartite hairs, the paraxonemal rod has a dentate appearance, and a two-gyred transitional helix is present between two transitional plates. Microtubular roots, striated roots, and a second basal body are absent. A thin organic theca surrounds most of the cell. There is a single chloroplast with a girdle lamella and a single, dense mitochondrion with tubular cristae. A single Golgi body with swelled cisternae lies beneath the flagellum, and each cell has an ejectile organelle that putatwely releases a cylindrical structure. A vacuole, or cluster of vacuoles, contains the putative carbohydrate storage product. The 18S rRNA gene was sequenced completely in both directions, excluding three primer regions. When compared to the same gene sequence from other organisms, Pelagomonas calceolata gen. et sp. nov. occupies an unresolved position among other chromophyte algae and is distinct from members of any of these classes. Based on morphological, ultrastructural, and molecular data, we describe this alga as a new species, and we place this highly unusual new species in a new genus, family, order, and class.     

MORPHOLOGY OF THE SUBANTARCTIC RED ALGA CENACRUM SUBSUTUM GEN. ET SP. NOV. (RHODYMENIALES) FROM MACQUARIE ISLAND1

The red alga Cenacrum subsutum gen. et sp. nov. is described from material collected at Macquarie Island in the subantarctic between November 1977 and February 1978. The habit and carposporophyte development are similar to members of the family Rhodymeniaceae (Rhodymeniales), but certain vegetative features are unique. The frond is a variously incised or lobed foliose blade with hollow apices above and a medulla which becomes progressively filled basipetally with ingrowing rhizoidal filaments. Details of carpogonial branch, auxiliary cell, connecting cell and gonimoblast anatomy are given, as well as observations on the habitats and distribution of the species.     

OCTOSPORIELLA COLORADOENSIS GEN. ET SP. NOV., A NEW TETRASPORALEAN GREEN ALGA FROM TWO COLORADO MOUNTAIN LAKES1

A new green alga, Octosporiella coloradoensis, belonging to the order Tetrasporales, family Tetrasporaceae, is described from Colorado mountain lakes. Colonies are planktonic or attached, the latter often forming loosely aggregated colonial complexes, thus creating an irregularly shaped complex. Individual colonies are spherical and consist of eight subcolonies, with each subcolony having spherically arranged octads of cells. Each vegetative cell bears two pseudoflagella that extend well beyond the colonial sheaths. Cell division is by eleutheroschisis and may be synchronous or asynchronous. Daughter colony formation is apparently coenobic, with each cell in the octad forming new subcolonies of eight cells each. Zoospore formation may precede daughter colony formation but the flagella remain rigid and non-motile. Large akinetes form in response to nutrient depletion. These germinate to produce eight aplanospores which divide to reconstitute a typical colony of Octosporiella. Sexual reproduction was not observed.     

ATRACTOMORPHA ECHINATA GEN. ET SP. NOV., A NEW ANISOGAMOUS MEMBER OF THE SPHAEROPLEACEAE (CHLOROPHYCEAE)1,2

Atractomorpha echinata gen. et sp. nov. is described from isolates derived from zygotes present in a dry soil sample obtained from Texas. The new genus is distinguished from Sphaeroplea primarily by its pattern of vegetative growth. While Sphaeroplea is distinctly filamentous with numerous coenocytic cells uniseriately arranged, Atractomorpha grows as individual, multinucleate, spindle-shaped cells with sharply pointed extremities. Such cells may vary considerably in length (25–6000 μm, or more) and normally lack septa. In young, rapidly growing cultures the cells often attain lengths of 300–500 μm, but rarely exceed 1800 μm. The new species is further characterized by: (1) the regular formation of biflagellate zoospores in asexual reproduction, (2)anisogamy (occasionally oogamy) and (3) the size and ornamentation of its zygotes. Variations in vegetative morphology are discussed as are conditions for obtaining gametogenesis.     

STARRIA ZIMBABWEËNSIS (CYANOPHYCEAE) GEN. NOV. ET SP. NOV.: A FILAMENT TRIRADIATE IN TRANVERSE SECTION1

A new filamentous bluegreen alga Starria zimbabweënsis gen. nov. et sp. nov. isolated from a soil sample collected near Zimbabwe, Southern Rhodesia, has a unique triradiate morphology. In transverse section each narrow cell possesses three arm-like projections, separated by 120° and in which pigment is concentrated. Filaments may be straight or twisted and various clonable biradiate forms have originated in cultures initiated from the triradiate type. Cell ultra-structure is typical of the Oscillatoriaceae except that 70 nm pit-like pores occur throughout the L-II layer of the longitudinal walls. Wall structure of deviant forms is identical to that of the triradiate “wild type.” The organism is assigned to the Oscillatoriaceae rather than to the Gomontiellaceae or to a new family.     

NEW ENDOLITHIC CYANOPHYTES FROM THE NORTH ATLANTIC OCEAN: I. CYANOSACCUS PIRIFORMIS GEN. ET SP. NOV.1

This paper describes a new genus and species of endolithic microorganism, Cyanosaccus piriformis Lukas and Golubic (Cyanophyta, Pleurocapsales). It is characterized by 1) having one to four spherical to pear-shaped cells within a stalked, gelatinous sheath, 2) its mode of reproduction by release of a large number of baeocytes produced by the proximal daughter cell following transverse binary fission of the parent cell, and 3) its ability to bore into and dwell within carbonate substrates in the marine environment. Its habit of asymmetrical sheath production allies it with the common microboring genera Hyella and Solentia within the family Hyellaceae. Cyanosaccus is a common inhabitant of mollusk shells found in water depths ranging from +0.5 to –75 m MLW on the eastern Florida continental margin and in carbonate sands or rocks in the intertidal and subtidal zones of the Bermuda and Bahama Islands. Its distribution within and among inhabited substrates is patchy due to its mode of reproduction and growth.     

中国中三叠世龙蝎蛉新科的发现(昆虫纲,长翅目)

记述龙蝎蛉新科Drakonochoristidae fam. nov.和1新亚科及其2新属、种和1个老亚科。2新属种的化石标本采自中国陕西铜川中三叠统铜川组下段上部的灰绿色泥岩和页岩。新科性质及其分类位置在文中进行讨论。新科的建立填补这个类群在中国的空白,同时对于小蝎蛉科Nannochoristidae和二叠蝎蛉科Permochoristidae的演化关系的研究有一定的意义。这些新属、种系陕西昆虫群(陕西生物群的一个类别)铜川昆虫组合的新成员。铜川组的时代相当于欧洲拉丁尼期(Ladinian Stage)。     

COMPARATIVE DEVELOPMENT OF THE RED ALGAL PARASITES BOSTRYCHIOCOLAX AUSTRALIS GEN. ET SP. NOV. AND DAWSONIOCOLAX BOSTRYCHIAE (CHOREOCOLACACEAE,RHODOPHYTA)1

The development of two red algal parasites was examined in laboratory culture. The red algal parasite Bostrychiocolax australis gen. et sp. nov., from Australia, originally misidentified as Dawsoniocolax bostrychiae (Joly et Yamaguishi-Tomita) Joly et Yamaguishi-Tomita, completes its life history in 6 weeks on its host Bostrychia radicans (Montagne) Montagne. Initially the spores divide to form a small lenticular cell, and then a germ tube grows from the opposite pole. Upon contact with the host cuticle, the germ tube penetrates the host cell wall. The tip of the germ tube expands, and the spore cytoplasm moves into this expanded tip. The expanded germ tube tip becomes the first endophytic cell from which a parasite cell is cut off that fuses with a host tier cell. The nuclei of this infected host cell enlarge. As parasite development continues, other host-parasite cell fusions are formed, transferring more parasite nuclei into host cells. The erumpent colorless multicellular parasite develops externally on the host, and reproductive structures are visible within 2 weeks. Tetrasporangia are superficial and cruciately or tetra-hedrally divided. Spermatia are formed in clusters. The carpogonial branches are four-celled, and the carpogonium fuses directly with the auxiliary (support) cell. The mature carposporophyte has a large central fusion cell and sympodially branched gonimoblast filaments. Early stages of development differ markedly in Dawsoniocolax bostrychiae from Brazil. Upon contact with the host, the spore undergoes a nearly equal division, and a germ tube elongates from the more basal of the two spore cells, penetrates the host cell wall, and fuses with a host tier cell. Subsequent development involves enlargement of the original spore body and division to form a multicellular cushion, from which descending rhizoidal filaments form that fuse with underlying host cells. This radically different development is in marked contrast to the final reproductive morphology, which is similar to B. australis and has lead to taxonomic confusion between these two entities. The different spore germination patterns and early germ-ling development of B. australis and D. bostrychiae warrant the formation of a new genus for the Australian parasite.     

DEUCALION GEN. NOV. AND ANISOSCHIZUS GEN. NOV. (CERAMIACEAE,CERAMIALES), TWO NEW PROPAGULE-FORMING RED ALGAE FROM SOUTHERN AUSTRALIA1

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.     

FURTHER STUDIES OF PRESUMEDLY PRIMITIVE GREEN ALGAE,INCLUDING THE DESCRIPTION OF PEDINOPHYCEAE CLASS. NOV. AND RESULTOR GEN. NOV.1

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.     

MORPHOLOGY AND MOLECULAR PHYLOGENY OF AUREOPHYCUS ALEUTICUS GEN. ET SP. NOV. (LAMINARIALES,PHAEOPHYCEAE) FROM THE ALEUTIAN ISLANDS1

A previously unknown species of kelp was collected on Kagamil Island, Aleutian Islands. The species can be easily distinguished from any known laminarialean alga: the erect sporophytic thallus is composed of a thin lanceolate blade attaining ～2 m in height and ～0.50 m in width, without midrib, and the edge of the blade at the transition zone is thickened to form a V‐shape; the stipe is solid and flattened, slightly translucent, attaining ～1 m in length; the holdfast is semidiscoidal and up to 0.15 m in diameter. Anatomically, the blade has the typical trumpet‐shaped hyphae characteristic of the Chordaceae and derived foliose laminarialean species (i.e., Alariaceae/Laminariaceae/Lessoniaceae). No hair pits or mucilaginous structures were observed on the blade or stipe. No fertile sporophytes were collected, but abundant juvenile sporophytes were observed in the field. In the molecular phylogenetic analyses using chloroplast rbcL gene, nuclear ITS1‐5.8S‐ITS2 rDNA, and mitochondria nad6 DNA sequences, the new species (Aureophycus aleuticus gen. et sp. nov.) showed a closer relationship with Alariaceae of conventional taxonomy, or the “Group 1” clade of Lane et al. (2006) including Alaria and related taxa than with other groups, although the species was not clearly included in the group. Aureophycus may be a key species in elucidating the evolution of the Alariaceae within the Laminariales. Because of the lack of information on reproductive organs and insufficient resolution of the molecular analyses, we refrain from assigning the new species to a family, but we place the new species in a new genus in the Laminariales.     

TETREUTREPTIA POMQUETENSIS GEN. ET SP. NOV. (EUGLENOPHYCEAE): A QUADRIFLAGELLATE,PHOTOTROPHIC MARINE EUGLENOID1

A new euglenoid genus and species, Tetreutreptia pomquetensis, is described from winter waters of Maritime Canada. This phototrophic species is characterized by four emergent heterodynamic flagella, two about the length of the cell and two less than one-half this length. Tetreutreptia pomquetensis has features in common with species of Eutreptiella while it differs in several respects from any of the described species of that genus. It could be assigned to the order Eutreptiales or Euglenamorphales sensu Leedale or the order Euglenales sensu Farmer. This new alga has a narrow range of temperature tolerance; it grows best from 0° to 7° C and dies at temperatures above 10° C. The optimum salinity for growth was near full-strength seawater. Growth conditions for the alga define the conditions whence this species was isolated.     

MORPHOLOGY AND MOLECULAR ANALYSES OF THREE TOXIC SPECIES OF GAMBIERDISCUS (DINOPHYCEAE): G. PACIFICUS, SP. NOV., G. AUSTRALES, SP. NOV., AND G. POLYNESIENSIS, SP. NOV.

Three new dinoflagellate species, Gambierdiscus polynesiensis, sp. nov., Gambierdiscus australes, sp. nov., and Gambierdiscus pacificus, sp. nov., are described from scanning electron micrographs. The morphology of the three new Gambierdiscus species is compared with the type species Gambierdiscus toxicus Adachi et Fukuyo 1979, and two other species: Gambierdiscus belizeanus Faust 1995 and Gambierdiscus yasumotoi Holmes 1998. The plate formula is: Po, 3′, 7", 6C, 8S, 5‴, 1p, 2". Culture extracts of these three new species displayed both ciguatoxin- and maitotoxin-like toxicities. The following morphological characteristics differentiated each species. 1) Cells of G. polynesiensis are 68–85 μm long and 64–75 μm wide, and the cell’s surface is smooth. They are identified by a large triangular apical pore plate (Po), a narrow fish-hook opening surrounded by 38 round pores, and a large, broad posterior intercalary plate (1p) wedged between narrow postcingular plates 2‴ and 4‴. Plate 1p occupies 60% of the width of the hypotheca. 2) Cells of G. australes also have a smooth surface and are 76–93 μm long and 65–85 μm wide in dorsoventral depth. They are identified by the broad ellipsoid apical pore plate (Po) surrounded by 31 round pores and a long and narrow 1p plate wedged between postcingular plates 2‴ and 4‴. Plate 1p occupies 30% of the width of the hypotheca. 3) Cells of G. pacificus are 67–77 μm long and 60–76 μm wide in dorsoventral depth, and its surface is smooth. They are identified by the four-sided apical pore plate (Po) surrounded by 30 round pores. A short narrow 1p plate is wedged between the wide postcingular plates 2‴ and 4‴. Plate 1p occupies 20% of the width of the hypotheca. These three newly described species were also characterized by isozyme electrophoresis and DNA sequencing of the D8–D10 region of their large subunit (LSU) rRNA genes. The consistency between species designations based on SEM microscopy and classification inferred from biochemical and genetic heterogeneities was examined among seven isolates of Gambierdiscus. Their classification into four morphospecies was not consistent with groupings inferred from isozyme patterns. Three molecular types could be distinguished based on the comparison of their LSU rDNA sequences. Although G. toxicus TUR was found to be more closely related to G. pacificus, sp. nov. than to other G. toxicus strains, the molecular classification was able to discriminate G. polynesiensis, sp. nov. and G. australes, sp. nov. from G. toxicus. These results suggest the usefulness of the D8–D10 portion of the Gambierdiscus LSU rDNA as a valuable taxonomic marker.     

ATRACTOMORPHA PORCATA SP. NOV., A NEW MEMBER OF THE SPHAEROPLEACEAE (CHLOROPHYCEAE) FROM CALIFORNIA1

Atractomorpha porcata sp. nov. is described from culture isolates derived in 1981 from zygotes present in a 28 year old, dried soil sample collected from near Lemon-cove, Tulare County, California. Vegetative individuals are coenocytic, spindle-shaped unicells with long, thin-pointed apices. Asexual reproduction is by means of large, biflagellate zoospores or, frequently, by aplanospores. Sexual reproduction is usually monoecious, with a single spindle-shaped gametangial cell producing small, biflagellate male gametes at either end, and larger female gametes in the midportion. Female gametes are often biflagellate, but more commonly they lack flagella and are liberated by squeezing through slit-like openings in the gametangial wall. Sexual reproduction may thus be considered as either oogamous or anisogamous, depending on whether or not a particular female gamete has flagella; most often it is oogamous. Atractomorpha porcata is readily distinguished from A. echinata, the only other known member of the genus, by (1) its greater tendency toward oogamy (versus anisogamy), (2) its bisexual gametangia, (3) its frequent production of aplanospores in asexual reproduction, (4) its unusual primary membranes that frequently bear long, delicate bristles, and (5) its distinctive zygote wall ornamentation.     

THE ULTRASTRUCTURE OF PYRAMIMONAS PSEUDOPARKEAE SP. NOV. (PRASINOPHYCEAE) FROM SOUTH AFRICA1

The ultrastructure of Pyramimonas pseudoparkeae sp. nov., a member of the class Prasinophyceae occurring in tidal pools along the east, south and west coast of South Africa, is described. The cell surface is covered by three distinctive body scales whilst the flagellar surfaces possess four types of scales. The structure of these scales is described. P. pseudoparkeae resembles Pyramimonas parkeae Norris and Pearson but differs in the structure of the type 2 body scale. The symmetry and ultrastructure of the cell are described with special attention given to the flagellar apparatus. Preliminary information on the life cycle of this species is presented. This new species is compared with other closely related members of the genus Pyramimonas.     

CACHONINA ILLDEFINA SP. NOV. (DINOPHYCEAE): CHLOROPLAST TUBULES AND DEGENERATION OF THE PYRENOID1

A new species of the dinoflagellate genus Cachonina, C. illdefina sp. nov., was isolated from a red tide off El Capitan State Park, Santa Barbara County, California, in October 1973. The organism is light yellowgreen in color with deeply incised girdle and sulcal grooves. Electron microscopy of the organism, revealed a typical dinokaryotic nucleus. The chloroplasts of the organism are connected, and often contain microtubule-like elements, 25 nm diam. The pyrenoids are characterized as excluding chloroplast thylakoids and ribosomes, although containing an amorphous matrix and numerous tubular invaginations from the cytoplasm. The pyrenoids become detached from the chloroplasts and degenerate into small vesicles. C. illdefina is not bioluminescent.     

NORTH CAROLINA MARINE ALGAE. IX. ONSLOWIA ENDOPHYTICA GEN. ET SP. NOV. (PHAEOPHYTA,SPHACELARIALES) AND NOTES ON OTHER NEW RECORDS FOR NORTH CAROLINA1

Four benthic algae are reported here for the first time in the North Carolina flora. The new brown algal genus and species, Onslowia endophytica Searles, is described as an endophyte of Halymenia floridana from the North Carolina continental shelf. New records of Boodleopsis pusilla and Naccaria corymbosa from North Carolina constitute range extensions of these tropical species on the American coast north from Florida. Blastophysa rhizopus, an endophyte and epiphyte known from the North Atlantic coast of Europe and America as well as the Caribbean is reported from North Carolina for the first time and in a new host, Predaea feldmannii.     

禽棒恙螨属属征的商榷和肩棒恙螨属,新属的建立（蜱螨亚纲：恙螨科）

本文对禽棒恙螨属Ｏｒｎｉｔｈｏｇａｓｔｉａ的属征提出商榷,并建立肩棒恙螨属,新属Ｏｍｏｇａｓｔｉａ ｇｅｎ．ｎｏｖ．来安置Ｎｅｏｓｃｈｏｅｎｇａｓｔｉａ ｒｉｖｅｒｓｉ Ｗｈａｒｔｏｎ ｅｔ Ｈａｒｄｃａｓｔｌｅ,１９４６。