Rhizochrysidopsis vorax,n. gen., n. sp.

Zusammenfassung Die Art ist durch eine bedeutende Variation der Zellgröße, damit auch des Chromatophors und des Kerns ausgezeichnet. Mit steigender Zellgröße nimmt die Zahl der kontraktilen Vakuolen von zwei auf mindestens acht zu. — Unter Umständen erfolgt exzessive animalische Ernährung; es werden auch im Vergleich zum Zellkörper sehr große Algenzellen aufgenommen und verdaut.     

Monopylocystis visvesvarai n. gen., n. sp. and Sawyeria marylandensis n. gen., n. sp.: two new amitochondrial heterolobosean amoebae from anoxic environments

Two new species of heterolobosean amoebae from anoxic environments, Monopylocystis visvesvarai and Sawyeria marylandensis, are described on the basis of light microscopy, electron microscopy, and their phylogenetic affiliation based on analyses of nuclear small-subunit ribosomal RNA gene sequences. Both species lack mitochondria but have organelles provisionally interpreted as hydrogenosomes, and neither can tolerate aerobic conditions. As their conditions of culture do not exclude all oxygen, they may be microaerophiles rather than strict anaerobes. Both species have unusual nucleolar morphologies. Monopylocystis visvesvarai, from a marine sediment, has nucleolar material distributed around the nuclear periphery. It is the first non-aerobic heterolobosean protist for which a cyst is known; the cyst is unmineralized and unornamented except for a single, raised, plugged pore. Sawyeria marylandensis, from an iron-rich freshwater stream, has nucleolar material distributed in one or two parietal masses, which persist during mitosis. In phylogenetic analyses of small-subunit rRNA gene sequences, Monopylocystis visvesvarai, Sawyeria marylandensis and Psalteriomonas lanterna converge to form a single clade of non-aerobic (anaerobic/microaerophilic) heteroloboseans.     

Norigondolella n. gen., eine neue obertriassische Conodontengattung

The development of the genus concept for platform-bearing gondolellid conodonts is discussed. The collective genusNeogondolella Bender & Stoppel s. l. must be subdivided into several genera separated mostly by morphological differences of their platform elements. Only for these genera, but not forNeogondolella s. l., differential diagnoses againstGondolella Stauffer & Plummer s. l. can be given.Norigondolella n. gen., species of which were formerly placed intoParagondolella Mosher s. l.,Gondolella Stauffer & Plummer s. l. orNeogondolella Bender & Stoppel s. l., is a typical gondolellid platform conodont genus of topmost Triassic (Norian-Rhaetian) pelagic sediments. It has evolved from Carnian representatives ofParagondolella, but the lower surface of the platform element shows considerable similarities (homoeomorphy) to the Middle Carboniferous to Middle Permian genusMesogondolella Kozur.     

Eremotyle affixa,n. gen., n. sp., eine neue Protococcale (Chlorophycee)

Ohne ZusammenfassungDie Veröffentlichung dieser Untersuchungen fällt zusammen mit der Feier des 70. Geburtstages Prof. Dr.Franz Ruttners. Der Verf. möchte nicht versäumen, mit seinem Glückwunsch dem Jubilar auch seinen herzlichsten Dank auszusprechen: hat er ihm doch zuerst als Student, später als junger Dozent, endlich als Kollege vielerlei Arten von Belehrung, Anregung und Förderung zu verdanken. Mögen diese Zeilen der Erinnerung an manche gemeinsam verlebte Stunden gewidmet sein!     

Sauertylenchus labiodiscus n. gen., n. sp., from Australia (Nematoda:Tylenchorhynchinae)

Sauertylenchus labiodiscus n. gem, n. sp. is described and illustrated from soil around Rhagodia sp. in Australia. It can be distinguished from the most closely related genus Tylenchorhynchus Cobb, 1913 by the distinctly set-off, rounded, lip region with a conspicuous labial disc, and long thin stylet. The face view and spicules of Sauertylenchus labiodiscus are illustrated with scanning electron micrographs. The subfamilies Tylenchorhynchinae and Merlininae ale discussed.     

Thermus aquaticus gen. n. and sp. n., a Nonsporulating Extreme Thermophile

The isolation of a new thermophilic bacterium, Thermus aquaticus gen. n. and sp. n., is described. Successful enrichment requires incubation at 70 to 75 C, and the use of nutrient media relatively dilute with respect to the organic components. Strains of T. aquaticus have been isolated from a variety of thermal springs in Yellowstone National Park and from a thermal spring in California. The organism has also been isolated from man-made thermal habitats, such as hot tap water, in geographical locations quite distant from thermal springs. Isolates of T. aquaticus are gram-negative nonsporulating nonmotile rods which frequently form long filaments at supraoptimal temperatures or in the stationary phase. All isolates form a yellow cellular pigment, probably a carotenoid. A characteristic structure formed by all isolates is a large sphere, considerably larger than a spheroplast. These large spheres, as well as lysozyme-induced spheroplasts, are resistant to osmotic lysis. Deoxyribonucleic acid base compositions of four strains were determined by CsCl density gradient ultracentrifugation and found to be between 65.4 and 67.4 moles per cent guanine plus cytosine. The growth of all isolates tested is inhibited by fairly low concentrations of cycloserine, streptomycin, penicillin, novobiocin, tetracycline, and chloramphenicol. Nutritional studies on one strain showed that it did not require vitamins or amino acids, although growth was considerably faster in enriched than in synthetic medium. Several sugars and organic acids served as carbon sources, and either NH(4) (+) or glutamate could serve as nitrogen source. The organism is an obligate aerobe and has a pH optimum of 7.5 to 7.8. The optimum temperature for growth is 70 C, the maximum 79 C, and the minimum about 40 C. The generation time at the optimum is about 50 min. The possible relationships of this new genus to the myxobacteria, flexibacteria, and flavobacteria are discussed.     

Enterospora canceri n. gen., n. sp., intranuclear within the hepatopancreatocytes of the European edible crab Cancer pagurus

Only 1 genus (Nucleospora) within 1 family (Enterocytozoonidae) of the Microsporidia contains species that are parasitic within the nuclei of their host cells; to date, all described intranuclear Nucleospora spp. parasitise fish. This study describes the first intranuclear microsporidian parasite of an invertebrate, the European edible crab Cancer pagurus L. (Decapoda: Cancridae). Infected crabs displayed no obvious external signs, and maximum apparent prevalence of infection within a monthly sample was 3.45%. Infected hepatopancreatic tubules were characterised by varying numbers of hypertrophic and eosinophilic nuclei within epithelial cells. Parasite stages appeared as eosinophilic granular accumulations causing margination of host chromatin. In advanced cases, the tubule epithelia degenerated, with parasites and sloughed epithelial cells appearing in tubule lumens. All life stages of the parasite were observed within host nuclei. Uninucleate meronts were not detected, although binucleate stages were observed. Multinucleate plasmodia (sporogonal plasmodia) contained up to 22 nuclei in section, and late-stage plasmodia contained multiple copies of apparatus resembling the polar filament and anchoring disk, apparently associated with individual plasmodial nuclei. As such, aggregation and early assembly of sporoblast components took place within the intact sporogonial plasmodium, a feature unique to the Enterocytozoonidae. Liberation of sporoblasts from plasmodia or the presence of liberated sporoblasts was not observed in this study. However, large numbers of maturing and mature spores (measuring 1.3 +/- 0.02 x 0.7 +/- 0.01 microm) were frequently observed in direct contact with the host nucleoplasm. Considering the shared features of this parasite with microsporidians of the family Enterocytozoonidae, and the unique presence of this parasite within the nucleoplasm of decapod crustacean hepatopancreatocytes, this parasite (Enterospora canceri) is proposed as the type species of a new genus (Enterospora) of microsporidian. Molecular taxonomic work is now required, comparing Enterospora to Enterocytozoon and Nucleospora, the 2 other genera within the Enterocytozoonidae.     

Notogaeanemertes folzae gen. n., sp. n., an additional ecologically restricted hoplonemertean from New Zealand

Notogaeanemertes folzae gen. n., sp. n., a monoecious and ovoviviparous hoplonemertean, is described from the supra-littoral at Kaikoura, New Zealand. It shares more characters with group I terrestrial nemerteans than with group II which brings into question the significance of certain features in the systematics of semiterrestrial/terrestrial nemerteans.     

Actiniscus canadensis n. sp., A. pentasterias Ehrenberg v. arcticus n. var., Pseudoactiniscus apentasterias n. gen., n. sp., Marine Relicts in Canadian Arctic Lakes

SYNOPSIS. The family Actiniscaceae Kützing, 1845, (generally placed in the dinoflagellates) includes species derived from Actiniscus pentasterias Schütt, some of which became lacustrine relicts. A. pentasterias v. arcticus. living in Arctic and Altantic waters, differs from the Mediterranean species in having a greater number of siliceous skeletons (pentasters). Advanced atrophy of pentasters in lacustrine A. canadensis , and absence of such structures in Pseudoactiniscus apentasterias , probably results from decreased salinity and an undetermined ecologic factor. Morphogenesis and physiologic transformation of past euryhaline Actiniscaceae into contemporary limnobionts began, presumably, during the prelimnic phase of Great Bear Lake and Keyhole Lake. Arctic Actiniscus which exist under subzero temperatures and endure 10-month-long winters, appear to satisfy their energy requirements by heterotrophy and frequent phagocytosis. Survival of lacustrine Actiniscus species in both Arctic lakes seems possible because of lack of competition from co-existing phytoplankton organisms which can endure extreme dystrophic conditions.