Comparative phylogenetic study of Stichotrichia (Alveolata: Ciliophora: Spirotrichea) based on 18S-rDNA sequences.

Since molecular phylogenies of stichotrich ciliates started to be published, some remarkable contradictions to morphology-based classifications have been reported, such as the Convergent Evolution of Urostylids and Uroleptids (CEUU) hypothesis, the Halteria paradox, the polyphyly of Oxytricha and of Stichotrichia. We hypothesized the internal phylogeny of 18S-rDNA from 53 morphological species of stichotrichs and their relationships with Hypotrichia and Oligotrichia using parsimony and neighbor-joining methods, including new data from Pseudouroleptus caudatus and Strongylidium pseudocrassum. Competing phylogenetic scenarios were compared using statistical tests, and the results suggest the reconsideration of both CEUU and the position of Halteria among flexible-body oxytrichids. The polyphyly of Oxytricha was not rejected and the monophyly of Stichotrichia was accepted based on parsimony analysis if Pseudoamphisiella is considered an external (discocephalid related) taxon.

Ciliate protists from Cabiúnas Lagoon (Restinga de Jurubatiba, Macaé, Rio de Janeiro) with emphasis on water quality indicator Species and description of Oxytricha marcili sp. n.

We found 34 species of ciliate protists in the samples collected by the margins of Cabiúnas Lagoon during 2001. The ciliates were cultivated in the laboratory, where they were examined in vivo and identified through silver impregnation techniques. A new species, Oxytricha marcili (Ciliophora, Oxytrichidae), was found and characterized as follows: in vivo length about 60-80 microm x 30-40 microm wide; on average 22 adoral membranelles; 18 left marginal cirri; 18 right marginal cirri; and 3 small caudal cirri. All specimens analyzed presented 7 frontal cirri (3 anterior + 4 posterior), 1 buccal cirrus, 4 ventral cirri (3 postoral + 1 pre-transverse), and 5 transverse cirri. Among the species found, some are considered as water quality indicators ranging from alpha-mesosaprobity to polysaprobity and isosaprobity.

Ciliate protists from Cabiúnas Lagoon (Restinga de Jurubatiba, Macaé, Rio de Janeiro) with emphasis on water quality indicator species and description of Oxytricha marcili sp. n

Foram encontradas 34 espécies de protistas ciliados nas amostras coletadas nas margens da lagoa de Cabiúnas em 2001. Os ciliados foram cultivados em laboratório, onde foram examinados in vivo e identificados por meio de técnicas de impregnação pela prata. Uma nova espécie, Oxytricha marcili (Ciliophora, Oxytrichidae), foi encontrada e caracterizada. Mede, in vivo, aproximadamente 60-80 mm de comprimento por 30-40 mm de largura. Apresenta em média 22 membranelas adorais, 18 cirros marginais esquerdos, 18 cirros marginais direitos e 3 cirros caudais de dimensões reduzidas. Todos os espécimes analisados apresentam 7 cirros frontais (3 anteriores + 4 posteriores), 1 cirro bucal, 4 cirros ventrais (3 pós-orais + 1 pré-transverso) e 5 cirros transversos. Dentre as espécies identificadas, algumas são consideradas indicadoras de qualidades de água que variam de alfa-mesossaprobidade a polissaprobidade e isossaprobidade.

Electron microscopic identification of the intestinal protozoan flagellates of the xylophagous cockroach Parasphaeria boleiriana from Brazil.

Flagellate protozoa of the hindgut of the xylophagous blattid Parasphaeria boleiriana were examined by light and electron microscopy. This species harbours two oxymonad species of the genera Monocercomonoides and Polymastix, the latter bearing Fusiformis bacteria on its surface. A diplomonad was present and has features of the genus Hexamita rather than Spironucleus. In addition, two trichomonads of the genera Monocercomonas and Tetratrichomastix were identified. A precise comparison with species of blattids and other insects was difficult because most of these flagellates have been described only by light microscopy after cell staining and there are few electron microscope studies and no molecular studies. None of the flagellates contained wood fragments in their food vacuoles and so evidently do not participate in the digestion of wood or cellulose.

Improvement of silver impregnation technique (Protargol) to obtain morphological features of protists ciliates, flagellates and opalinates

The research on ciliates, flagelates and opalinates have been widespread by the utilization of techniques employing silver impregnation (Protargol), modified by several authors. However, these are time consuming and its results are variable. The present work is a variant of the technique described by Tuffrau (1964, 1967) showing some adaptations made in our laboratory. The organisms can be preserved by different fixatives (alcoholic Bouin, Stieve's fluid, 2.5 percent glutaraldehyde and others) and then rinsed in destilled water followed by a fast clarification by 3 percent sodium hypochloride. If the organism is very sensitive to hypochloride, 4 percent sodium lauryl sulfate may be used and then washed 3 times in distilled water. The protista can be adhered to the glass slides with Mayer's glycerinated-albumin (1 glycerin vol. to 1 or 2 albumin vol.), diluted in water at a proportion of 1:10 Cv/v., or with 1 percent polylysine followed by fast washes with distilled water. After the slide preparation, they were covered with a layer of 0,8 percent Silver proteinate. Right after that, the slide has to be placed in a glass tray lined with moist tissue and covered to prevent the proteinate to dry. The tray was placed in a incubator at 40º-50ºC for 30 minutes. The slides are rinsed for 1 minute. with warm (35ºC) distilled water. The development of the material should be done with 0.4 percent hydroquinone with a maximum incubation time of 1 minute. It should be developed gradually, controlling the silver impregnation intensity by observation under optical microscope. Next, rinse in distilled water for 1 minute, and then, fix in 2,5 percent Sodium thiosulfate. Rinse the slide for two minutes before dehydrating it in an alcoholic serial 50-100º. Finally rinse the slides in xylene. Mount the slides with Entellan MerckTM or Canada balsam

Improvement of silver impregnation technique (protargol) to obtain morphological features of protists ciliates, flagellates and opalinates.

The research on ciliates, flagelates and opalinates have been widespread by the utilization of techniques employing silver impregnation (protargol), modified by several authors. However, these are time consuming and its results are variable. The present work is a variant of the technique described by Tuffrau (1964, 1967) showing some adaptations made in our laboratory. The organisms can be preserved by different fixatives (alcoholic Bouin, Stieve's fluid, 2.5% glutaraldehyde and others) and then rinsed in destilled water followed by a fast clarification by 3% sodium hypochloride. If the organism is very sensitive to hypochloride, 4% sodium lauryl sulfate may be used and then washed 3 times in distilled water. The protista can be adhered to the glass slides with Mayer's glycerinated-albumin (1 glycerin vol. to 1 or 2 albumin vol.), diluted in water at a proportion of 1:10 Cv/v., or with 1% polylysine followed by fast washes with distilled water. After the slide preparation, they were covered with a layer of 0,8% Silver proteinate. Right after that, the slide has to be placed in a glass tray lined with moist tissue and covered to prevent the proteinate to dry. The tray was placed in a incubator at 40 degrees - 50 degrees C for 30 minutes. The slides are rinsed for 1 minute. with warm (35 degrees C) distilled water. The development of the material should be done with 0.4% hydroquinone with a maximum incubation time of 1 minute. It should be developed gradually, controlling the silver impregnation intensity by observation under optical microscope. Next, rinse in distilled water for 1 minute, and then, fix in 2,5% Sodium thiosulfate. Rinse the slide for two minutes before dehydrating it in an alcoholic serial 50-100 degrees. Finally rinse the slides in xylene. Mount the slides with Entellan MerckTM or Canada balsam.

Structural and ultrastructural observations of the ciliate Phacodinium metchnicoffi certes, 1891 (Heterotrichea, Phacodiniida).

This work points out several specific ultrastructural characteristics of the ciliate Phacodinium metchnicoffi. The somatic infraciliature consists of several segments of aciliferous or partially ciliferous monokinetids or alignments of kinetosomes with a particular structuration. All alignments of kinetosomes in double rows are associated with striated kinetodesmal fibers and to a ribbon of postciliary microtubules. The transverse fibers are observed only from monokinetids showing also kinetosomes associated with a 1-2 ribbon of transverse microtubules. However, only the anterior kinetosome of the monokinetid presents a ribbon of transverse fibers and an isolated microtubule next to triplet 5. The somatic kinetosomes located in the zones surrounding the buccal area are clearly associated with a noded microfibrillar network and with nemadesmata on the remaining part of the cortex. The kinetosomes of adorai organelles show 1-2 transverse microtubules. Each organelle is provided with 4 rows of kinetosomes and on each organelle, the kinetosomes of the anterior row bear postciliary microtubules directed towards the front part of the membranelle. The kinetosomes of the left row are associated with 1 or 2 transverse microtubules (T2) as are the kinetosomes of the other rows. The paroral organelle consists of an internal row of kinetosomes accompanied by a succession of parallel small rows each consisting most often of 3 kinetosomes. Only the kinetosomes of the internal row bear postciliary microtubules and prepostciliary microtubules and also show a noded microfibrillar network connecting their proximal zones. Lastly, the taxonomic relationships between Transitella and Phacodinium are discussed.

Observations sur la structure et l'utrastructure du cilié Myxophthirus anomalocardiae gen.nov., sp.nov. (Scuticociliatida, Thigmophryidae), parasite du bivalve Anomalocardia brasiliana Gmelin, 1791.

We describe a new genus of Thigmophryidae which is characterized by the cytoskeleton of the thigmotactic area, the median position of the buccal cavity with paroral and adorai organelles. On the locomotive cortex, the kinetosomes are in pairs and ciliated with a median parasomal sac. With the posterior kinetosome are associated: a) a kinetodesmal fibre, b) a ribbon of postciliary fibres, c) a ribbon of transverse microtubules, d) a transverse tractus, e) a microfibrillar tractus. Two or three microtubules run along each kinety. On the thigmotactic cortex, each posterior kinetosome is associated with a kinetodesmal fibre, a postciliary ribbon, a ribbon of transverse fibres and a transverse tractus. Moreover, a skeletal fibre with periodic structure, at the proximal end of the kinetosomes, runs along the left of each kinety. The endoplasm is full of host cells or organisms of the palleal cavity. The ultrastructure of the ciliate is typical of Scuticociliates, just as the buccal organization, with presence of a scuticus. The paroral membrane is a row of dyads with a development of a microfibrillar network as at the level of the single adoral organelle the kinetosomes of which have postciliary fibres.