Zur Kenntnis der Neritina fluviatilis Müll.

Von Dr. R. Hilbert

First isolation of a rhabdovirus from perch Perca fluviatilis in Switzerland

Perca fluviatilis is a fish species of increasing interest to the Swiss fish farming industry. In recent years, recirculation systems have been specifically set up to increase production. In one of these farms, abnormal spiral swimming associated with elevated mortalities occurred in repeated batches of imported perch shortly after stocking on several occasions. No bacterial or parasitic etiology was detected, but a virus grown in bluegill fry (BF-2) cells was identified as perch rhabdovirus. Subsequent investigations of other samples suggested a viral tropism for the central nervous system (CNS). Phylogenetic analysis of the partial N and entire G gene sequences positioned this isolate in genogroup C of the species Perch rhabdovirus, with high nucleotide and amino acid (aa) sequence identities with the DK5533 strain isolated in Denmark in 1989. Comparative studies using other closely related isolates allowed the distinction of 2 serological Patterns among perch rhabdoviruses and the identification of a proline substitution by a serine in Position 147 of the glycoprotein potentially involved in antigenic differentiation. Even if perch imported onto the farm tested negative by virus isolation prior to transport, they may have been the origin of this outbreak since CNS tissue was not included in the samples that were analyzed. Another possibility might be a sub-clinical infection with a viral load in resident fish too low to be detected. This study reports the first isolation of a perch rhabdovirus in Switzerland, and emphasizes the necessity of optimizing diagnostic tools that facilitate better control of the risks associated with fish translocation.

Oenanthe fluviatilis Coleman : eine verkannte Blütenpflanze des europäischen Kontinents

von H. Glück

Oenthe fluviatilis Coleman

Von H. Glück

Anatomie und Entwicklungsgeschichte der Neritina fluviatilis /

Mode of access: Internet.

Phylogenetic position and ultrastructure of two Dermocystidium species (Ichthyosporea) from the common perch (Perca fluviatilis)

Sequences of small-subunit rRNA genes were determined for Dermocystidium percae and a new Dermocystidium species established as D. fennicum sp. n. from perch in Finland. On the basis of alignment and phylogenetic analysis both species were placed in the Dermocystidium-Rhinosporidium clade within Ichthyosporea, D. fennicum as a specific sister taxon to D. salmonis, and D. percae in a clade different from D. fennicum. The ultrastructures of both species well agree with the characteristics approved within Ichthyosporea: walled spores produce uniflagellate zoospores lacking a collar or cortical alveoli. The two Dermocystidium species resemble Rhinosporidium seeberi (as described by light microscope), a member of the nearest relative genus, but differ in that in R. seeberi plasmodia have thousands of nuclei discernible, endospores are discharged through a pore in the wall of the sporangium, and zoospores have not been revealed. The plasmodial stages of both Dermocystidium species have a most unusual behaviour of nuclei, although we do not actually know how the nuclei transform during the development. Early stages have an ordinary nucleus with double, fenestrated envelope. In middle-aged plasmodia ordinary nuclei seem to be totally absent or are only seldom discernible until prior to sporogony, when rather numerous nuclei again reappear. Meanwhile single-membrane vacuoles with coarsely granular content, or complicated membranous systems were discernible. Ordinary nuclei may be re-formed within these vacuoles or systems. In D. percae small canaliculi and in D. fennicum minute vesicles may aid the nucleus-cytoplasm interchange of matter before formation of double-membrane-enveloped nuclei. Dermocystidium represents a unique case when a stage of the life cycle of an eukaryote lacks a typical nucleus.

Purificação e caracterização de uma ß-N-acetillhexosaminadase extraída do mamífero marinho Sotalia fluviatilis

This report shows 2232 times purification of a βNAcetylhexosaminidase from hepatic extracts from the sea mammal Sotalia fluviatilis homogenate with final recovery of 8,4%. Sequenced steps were utilized for enzyme purification: ammonium sulfate fractionation, Biogel A 1.5 m, chitin, DEAESepharose and hydroxyapatite chromatographies. The protein molecular mass was estimated in 10 kDa using SDSPAGE and confirmed by MALDITOF. It was found to have an optimal pH of 5.0 and a temperature of 60°C. Using pnitrophenylNAcetylβDglycosaminide apparent Km and Vmax values were of 2.72 mM and 0.572 nmol/mg/min, respectively. The enzyme was inhibited by mercury chloride (HgCl2) and sodium dodecil sulfate (SDS)

Presença de culicídeos em município de porte médio do Estado de São Paulo e risco de ocorrência de febre do Nilo Ocidental e outras arboviroses

INTRODUÇÃO: O objetivo deste estudo foi mensurar a diversidade de espécies de culicídeos, descrever sua abundância e variação sazonal em áreas urbanas e matas de São José do Rio Preto, SP, e discutir o risco de ocorrência de arboviroses. MÉTODOS: Coletas de larvas e de mosquitos adultos foram realizadas mensalmente, em 2006 e 2007, em área urbana e em quatro fragmentos de mata. No perímetro urbano, coletaram-se larvas nos sítios mais prováveis de oviposição para mosquitos do gênero Culex e nas matas foi realizada a coleta de mosquitos adultos, sendo que em duas utilizaram-se armadilhas CDC à noite e, em duas, aspirador de Nasci de dia. RESULTADOS: Na área urbana identificaram-se 34 espécies de culicídeos em um total de 8.683 exemplares; destes, 80,7% corresponderam ao Culex quinquefasciatus, 9,6% ao Culex grupo Coronator, 3,2% ao Aedes albopictus (3,2%) e 1,1% ao Ochlerotatus fluviatilis. A abundância de larvas de Cx. quinquefasciatus correlacionou-se negativamente com a chuva. Nas quatro matas, foram coletados 2.268 mosquitos distribuídos entre 10 gêneros, 46 espécies ou grupos. As mais abundantes foram Aedeomyia squamipennis, Culex. coronator, Culex (Mel.) seção Melanoconion, Culex declarator, Ochlerotatus scapularis, Anopheles triannulatus, Culex bidens/interfor e Culex habilitator/pseudojhantinosoma. CONCLUSÕES: A abundância de Cx. quinquefasciatus na área urbana e a presença de outros culicídeos nas áreas urbanas e de matas apontam para a possibilidade de transmissão do vírus do Nilo Ocidental e de outras arboviroses em São José do Rio Preto e outras cidades do Brasil, sendo fundamental o estabelecimento de medidas visando à vigilância destas arboviroses.

Culicidae (Diptera) em área de barragem em Santa Catarina e no Rio Grande do Sul

A composição de Culicidae do lago de Barra Grande, situado entre os municípios de Esmeralda (Rio Grande do Sul) e Anita Garibaldi (Santa Catarina), foi realizada com coletas mensais. Vinte e quatro espécies foram identificadas dentre um total de 1.185 espécimes (74,7% adultos e 25,3% imaturos), sendo Aedes fluviatilis Lutz a espécie mais frequente. Algumas espécies constituem novos registros e são interesse em saúde pública. O fato sugere que mudanças ambientais na área podem alterar a relação entre humanos e mosquitos vetores

The ocular morphology of the southern hemisphere lamprey Geotria australis gray with special reference to optical specialisations and the characterisation and phylogeny of photoreceptor types

This paper describes the ocular morphology of young adults of the southern hemisphere lamprey Geotria australis, the sole representative of the Geotriidae, and makes comparisons with those of holarctic lampreys (Petromyzontidae). As previously reported for the holarctic lamprey Ichthyomyzon unicuspis [Collin and Fritzsch, 1993], the lens of G. australis is non-spherical and possesses a cone-shaped posterior that may be capable of mediating variable focus. The avascular retina of G. australis is well differentiated, containing three retinal ganglion cell populations, three layers of horizontal cells and three photoreceptor types, in contrast to petromyzontids that contain only two photoreceptor types (short and long), G. australis possesses one rod-like (R1) and two cone-like (C1 and C2) photoreceptors. Although the rodlike receptor in G. australis may be homologous with the short receptors of holarctic lampreys, the two cone-like receptors have morphological characteristics that differ markedly from those of the long receptors of their holarctic counterparts. The features which distinguish the two cone-like receptors from those of the long receptor type in holarctic lampreys are the characteristics of the mitochondria and the presence of large amounts of two different types of stored secretory material in the endoplasmic reticulum of the myoid (refractile bodies). The endoplasmic reticulum of each receptor type has a different shape and staining profile and is polymorphic, each showing a continuum of distension. It is proposed that the presence of two cone-like photoreceptors with different characteristics would increase the spectral range of G. australis and thus be of value during the parasitic phase, when this lamprey lives in the surface marine waters. The irideal flap, present in G. australis but not petromyzontids, would assist in reducing intraocular flare during life in surface waters. The results of this study, which are discussed in the context of the proposed evolution of lampreys, emphasise that it is important to take into account the characteristics of the eyes of southern hemisphere lampreys when making generalizations about the eyes of lampreys as a whole.

Pulse-exposure effects of selected insecticides to juvenile Australian crimson-spotted rainbowfish (Melanotaenia duboulayi)

Laboratory toxicity studies were conducted in southeastern Queensland, Australia, to determine the acute lethal effects of a 1-h pulse exposure of selected insecticides to adult and juvenile (

Aedes (Stegomyia) aegypti L. e a culicideofauna associada em área urbana da região sul, Brasil

Foram mostrados alguns aspectos sobre a ecologia de 11 espécies de Culicidae que procriam em recipientes, em uma área urbana do Sul do Brasil. Os mais variados tipos de recipientes foram listados como eficientes criadouros para larvas de culicídeos. Aedes aegypti apareceu como espécie recém-introduzida e limitada somente a duas áreas da cidade. As espécies predominantes foram: Culex quinquefasciatus, Culex coronator, Aedes aegypti, Aedes fluviatilis e Limatus durhamii.

Flebotomíneo em fragmentos de Mata Atlântica na Região Metropolitana do Recife, PE

Foi realizada uma investigação sobre a distribuição da fauna flebotomínica em 4 fragmentos da Mata Atlântica na Região Metropolitana do Recife. Consistiu na captura de insetos adultos com auxilio de armadilhas luminosas CDC. 1.173 espécimes distribuídos em 11 espécies de Lutzomyia: Lutzomyia evandroi, Lutzomyia choti, Lutzomyia walkeri, Lutzomyia umbratilis, Lutzomyia brasiliensis, Lutzomyia sordellii, Lutzomyia claustrei, Lutzomyia wellcomei, Lutzomyia fluviatilis, Lutzomyia furcata e Lutzomyia aragaoi.