Microglena butcheri nov. sp., a flagellate from the English Lake District

Summary Microglena butcheri nov. sp. (Chrysophyceae) is described and figured. Morphology and asexual reproduction were investigated by light microscopy. It was not possible to maintain this organism in culture.

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Zusammenfassung Microglena butcheri nov. sp. (Chrysophyceae) wird beschrieben and abgebildet. Die Morphologie and die ungeschlechtige Vermehrung wurden durch Lichtmikroskopie untersucht. Es war nicht möglich, diesen Organismus zu kultivieren.

     

SYNUROPHYCEAE CLASSIS NOV., A NEW CLASS OF ALGAE

The silica-scaled algae (Synuraceae, Chrysophyceae sensu lato) are compared to other Chrysophyceae, Phaeophyceae and Bacillariophyceae with occasional comparisons to other chlorophyll c-containing algae, scaled protozoa and oomycete fungi. The silica-scaled algae have several unique characters which separate them from the above groups and based upon these differences a new order, Synurales ord. nov., and a new class, Synurophyceae class. nov., are described. The major distinguishing characters of the Synurophyceae class. nov. are: they have chlorophylls a and c₁ but lack chlorophyll c₂; their flagellar apparatus includes a microtubular root that loops around two parallel flagella and a flagellar root system which occurs in four absolute orientations; the photoreceptor consists of paired flagellar swellings which are not associated with the cell membrane and chloroplast; no eyespot is present; the nuclear envelope is not or is only weakly associated with the chloroplast endoplasmic reticulum. The Synurophyceae class. nov. are about equally distinct from the Chrysophyceae sensu stricto, Phaeophyceae and Bacillariophyceae when the class level characters are compared. Although the Phaeophyceae have a long history of being placed by themselves in the division Phaeophyta, and the Bacillariophyceae and Chrysophyceae have recently been placed alone in the Bacillariophyta and Chrysophyta, respectively, the similarities found among these classes suggest these algae are not so distinct that they require separate divisions. Tentatively, therefore, the Synurophyceae are placed in the division Phaeophyta along with the Bacillariophyceae and Chrysophyceae sensu stricto.     

The fine structure of Pseudopedinella pyriforme Carter (Chrysophyceae)

Pseudopedinella pyriforme Carter displays a second non-emergent flagellum and vestigial anterior tentacles. The trailing rhizopodium is without supporting microtubules, and seemingly arises from a posterior vesicle apparently associated with the Golgi apparatus. Stalked pyrenoids, so far unreported for any other member of the Chrysophyceae, are demonstrated. The structure of P. pyriforme is compared with members of the Chrysophyceae and Craspedamonadales and its taxonomic position is discussed.     

A NEW PHYLOGENY FOR CHROMOPHYTE ALGAE USING 16S-LIKE RRNA SEQUENCES FROM MALLOMONAS PAPILLOSA (SYNUROPHYCEAE) AND TRIBONEMA AEQUALE (XANTHOPHYCEAE)1

The 16S-like ribosomal RNA genes from Mallomonas papillosa Harris et Bradley (Synurophyceae) and Tribonema aequale Pascher (Xanthophyceae) were sequenced and compared to those of other eukaryotes. Mallomonas is closely related to Ochromonas (Chrysophyceae) and supports the general hypothesis of a close phylogenetic relationship between the Synurophyceae and Chrysophyceae. Tribonema is specifically related to Costaria costata (C. A. Agardh) Saunders (Phaeophyceae) demonstrating an unexpected phylogenetic relationship between the Xanthophyceae and Phaeophyceae. Distance and parsimony analysis place these four chromophyte genera in a complex evolutionary assemblage that includes the Bacillariophyceae and Oomycetes but excludes the Dinophyceae. The close relationship between the chromophyte algae and the Öomycete fungi supports the hypothesis that protists with tripartite hairs form a natural assemblage.     

THE OCCURRENCE OF CHLOROPHYLLS C1 AND C2 IN THE CHRYSOPHYCEAE1

We analyzed 34 strains representing 25 species of Chrysophyceae for chlorophylls c₁ and c₂ using thin-layer chromatography. Most organisms had both chlorophylls c₁ and c₂ in addition to chlorophyll a but 17 strains of 9 species of Synura and Mallomonas possessed only chlorophylls a and c₁. These are the first chlorophyll c-bearing algae which lack chlorophyll c₂. We postulate that at least some of the silica-scaled algae including Mallomonas and Synura may be distinct from other Chrysophyceae based upon pigmentation and other characters described in the literature.     

Synuraceae (Chrysophyceae) in the Netherlands

Summary Investigations of phytoplankton biomass development and species succession in the Oude Waal near Nijmegen revealed the importance of the Chrysophyceae (Table I).Submicroscopical structures of the Chrysophyceae are known to be species-specific. So electronmicroscopical observations have been introduced into the research program. Special attention has been paid to the (scale-bearing) Synuraceae. The analysis of weekly taken samples in the year 1979 revealed a typical temporal distribution pattern of the Synuraceae, mainly controlled by temperature. Particulary the genusSynura showed a succession of four species:S. uvella dominated at water temperatures from 10–14°C,S. glabra from 14–16°C,S. curtispina from 10–19°C andS. petersenii occurred at water temperatures ranging from 0–21°C.     

A new species of Pavlova from Madeira

Light microscope observations on Pavlova pinguis sp. nov. (Chrysophyceae), a marine flagellate, are described and it is compared with the type species P. gyrans. Recent observations on P. gyrans are given and the diagnoses of the genus and type species emended.     

Chrysocapsopsis rupicola: A new genus and species in the Chrysophyceae

Chrysocapsopsis rupicola gen. et sp. nov. (Chrysophyceae) is described. It differs from Chrysocapsa and the closely related genera Chrysocapselia and Tetrachrysis by possessing both epiphytic and planktonic forms within the same life-history. Reproduction is by budding which produces short irregular branches within a gelatinous mass. Four or more aplanospores are produced from each mother cell; no motile cells were observed.     

Lorica construction in Pseudokephyrion pseudospirale bourrelly

The lorica of the freshwater nannoplankton flagellate Pseudokephyrion pseudospirale (Chrysophyceae or Chrysomonadida) has been examined by light and electron microscopy and found to possess a microfibrillar structure which becomes thickened and obscured by mineral deposition. Taxonomic implications are discussed.     

Studies on generaMallomonas andSynura,and other plankton in freshwater with the electron microscope VIII. On three new species of chrysophyceae

Three new species (Chrysophyceae) which belong to the Torquata group of the genusMallomonas, to the Spinosa group of the genusSynura, and to the genusOhromonas were found from freshwater in the North-East of Japan by the aid of an electron microscope. They were namedMallomonas recticostata, Synura mammillosa, andOchromonas diademifera, respectively. The characteristics of the three new species are described here.     

Some aspects of the seasonal distribution of flagellates in mountain lakes

In a larger regional survey in Tyrol, phytoplankton species composition and biovolume of mid-altitude and high-mountain lakes was studied. Results from eight lakes showed that flagellates (mainly Chrysophyceae, Dinophyceae, and Cryptophyceae) are important components of the phytoplankton.In the mid-altitude lakes a spring and an autumn maximum of Chrysophyceae as well as a summer maximum of large dinoflagellates are observed, whereas Cryptophyceae and Dinophyceae show irregular distributions. In the high-mountain lakes the seasonal variations of phytoplankton, including flagellates, are limited by the long duration of the winter situation. However similar sequences of phytoplankton assemblages as in the midaltitude lakes can be observed. Flagellates in high-mountain lakes are important to sustain phytoplankton standing crop under the winter snow and ice cover.In order to show similarities and differences of high-mountain and mid-altitude lakes, vertical profiles of phytoplankton from three lakes and seasonal patterns of Gymnodinium uberrimum from two lakes are compared. In addition the patterns of cryptomonads differing in their ecological requirements (Cryptomonas spp. and Rhodomonas minuta) are shown for a meromictic mid-altitude lake.     

Some rare Chrysophyta from Swedish oligotrophic lakes

Five new species from oligotrophic forest and mountain lakes are described: Chrysolykos calceatus, Chrysolykos hamulatus, Chrysoikos complanatus, Pseudokephyrion gibbosum (all Chrysophyceae) and Tetraëdriella patiens (Xanthophyceae). Some unusual species described earlier were also found in the lakes investigated: Bitrichia ollula, Pseudokephyrion angulosum and Palatinella cyrtophora. Finds of Kephyrion boreale with two flagella are reported.     

Die Feinstruktur kristalloider Einschlüsse in Mitochondrien von Porterioochromonas stipitata

Summary The matrix of the mitochondria of Porterioochromonas stipitata Lewin (Chrysophyceae) often contains crystalloid inclusion bodies that are composed of hexagonally packed fibrils (or tubules). The fibrils have a diameter of 10 nm, their center-to-center spacing is 13,5 nm.     

Silica‐scaled chrysophytes from Abisko (Swedish Lapland)

The silica‐scaled chrysophyte flora of Swedish Lapland (near Abisko) was examined. Chrysophyte scales were found in 18 of the 32 investigated water bodies (lakes and pools). Altogether, 28 taxa from the classes Chrysophyceae and Synurophyceae were found. The most abundant species was Synura echinulata. Three species were observed for the first time in Sweden: Mallomonas maculata, M. rasilis and Spiniferomonas serrata.     

Chrysosphaerella (Pseudochrysosphaerella)solitaria,spec. nova (Chrysophyceae)

A new unicellular species of the genusChrysosphaerella (Chrysophyceae) was found in fresh-water ponds in Switzerland, Japan, and the U.S.A. It is described asC. solitaria. The genus is divided into two subgenera:Chrysosphaerella, comprising the colonial species, andPseudochrysosphaerella, the unicellular ones.     

Periphyton flora of some lotic and lentic environments of Hope Bay (Antarctic Peninsula)

A taxonomic study was made of the periphytic algal flora of some freshwater environments at Hope Bay, Antarctic Peninsula (63°27S; 56°59W), during summer 1992–1993. Seven lakes and two pools that are characterized by different trophic levels were studied. The largest, Boeckella Lake, has an important outflow (Prasiola Stream) that was also analyzed. Ninety-seven algal taxa, including specific and infraspecific entities, are recorded. Thirty-one new records for the Antarctic continent are described and illustrated. The flora comprises 44.4% Cyanophyceae, 21.6% Bacillariophyceae, 18.5% Chlorophyceae, 9.3% Tribophyceae, 4.2% Chrysophyceae and 2% Zygophyceae. The epilithic flora of Hope Bay shows a high species richness. Phormidiumfragile and Lyngbya lagerheimii were the most abundant species among the Cyanophyceae. In the algal mats we also found Chrysophyceae (mainly Hydrurus foetidus and Chrysococcus rufescens) and the macroscopic chlorophycean Prasiola crispa. Tribonema australis sp. nov. (Tribonematales, Tribophyceae) is put forward as a new species. Hormidium fluitans (Gay) Heering is renamed Klebshormidium fluitans.     

Freshwater scaled chrysophytes,heliozoa and thaumatomonad flagellates from Edo State,Nigeria

A total of nine silica-scaled chrysophytes (Chrysophyceae: two species each in Spiniferomonas and Paraphysomonas; Synurophyceae: five Mallomonas species), 16 heliozoa, and two scaled flagellates were recorded from 19 samples collected from Edo State, Nigeria, over a period covering both dry and rainy seasons in 2006–2007. Identifications were based on transmission electron microscopy. Eleven are new records for Africa, including a new species of Mallomonas, M. cribridomus. Also observed were two siliceous scaled colourless free-living thaumatomonad flagellates, Thaumatomastix nigeriensis and Gyromitus limax, the latter also a new record for Africa.     

A study of the nannoplankton flagellate Pedinella hexacostata vysotskii by light and electron microscopy

A strain of Pedinella hexacostata Vysotskii (Chrysophyceae, or Chrysomonadida) was grown in culture and examined by light and electron microscopy. Behaviour, phagotrophy and division have been observed and salinity tolerance tested experimentally. Pedinella is discussed with relation to Pseudopedinella and other members of the Pedinellaceae. The fine structure of the tentacles is compared with that of tentacles in some other Protozoa.     

The morphology and fine structure of the colourless colonial flagellate Anthophysa vegetans (O. F. Müller) Stein

A strain of Anthophysa vegetans (O. F. Müller) Stein (Chrysophyceae or Chrysomonadida) was grown in culture and examined in detail by light and electron microscopy. It was shown to be a typical, though apochlorotic, member of its class; features of interest include a well-developed leucoplast and a starch-like reserve product. Aspects of the largely inorganic stalk are also discussed.