113 resultados para Tetra fishes
Resumo:
The molluscs Heleobia castellanosae and Ampullaria canaliculata and cichlid fishes were collected from an artificial pond at Tres de Febrero Park (Buenos Aires city), between June 1994 and May 1995. One hundred and eighty of 2,467 H. castellanosae examined were infected with pre-adults of Lobatostoma jungwirthi, 112 of them in concurrent infections with digeneans. L. jungwirthi was significantly more prevalent in larger snails, especially those infected with larval digeneans, but the prevalence of infection did not fluctuate significantly throughout the year. A. canaliculata and cichlids smaller than 10 cm were not infected, but larger Cichlasoma facetum harboured adults of L. jungwirthi in their intestines. Experimental infections of C. facetum and Gymnogeophagus meridionalis with pre-adult aspidogastreans obtained from H. castellanosae were successful. The development of L. jungwirthi in the snail host involves five arbitrary growth phases. Its life-cycle is heteroxenous, similar to that described for L. manteri, with H. castellanosae as the intermediate host and cichlid fishes as the definitive host in this pond.
Resumo:
The morphology of the scolices and metascolices of 29 proteocephalid species, parasites of freshwater fishes from Brazil was compared by using scanning electron microscope, light and laser microscopy. The following species were evaluated: Proteocephalus vazzolerae, P. piramutab, Robertiella paranaensis, Travassiella avitellina, Monticellia loyolai, M. spinulifera, M. belavistensis, Houssayela sudobim, Zygobothrium megacephalum, Gibsoniela mandube, Cangatiella arandasi, Nomimoscolex sudobim, N. lopesi, N. admonticellia, N. piraeeba, N. pirarara, Harriscolex kaparari, Crepidobothrium eirasi, Spatulifer rugosa, Megathylacus brooksi, Choanoscolex abscisus, Amphoteromorphus peniculus, A. piraeeba, Paramonticellia itaipuensis, Peltidocotyle rugosa, Othinoscolex lenha, Rudolphiella rugata, R. piranabu, Jauella glandicephalus. Some features as overall shape of scolex, suckers, apical sucker, frontal glands and several kinds of metascolex were analyzed. The taxonomic importance of scolex and metascolex is discussed.
Resumo:
New records for nematode species recovered from elasmobranch fishes in Brazil are established and new systematical arrangements proposed. Parascarophis sphyrnae Campana-Rouget, 1955 from the spiral valve of Sphyrna zygaena is referred for the first time in South America as a new host record. Procamallanus (S.) pereirai Annereaux, 1946, from the spiral valve of Raja castelnaui is reported parasitizing an elasmobranch host. Nematode larvae of the genera Anisakis, Contracaecum, Pseudoterranova and Raphidascaris are listed from the stomach and spiral valves of several hosts. Anisakidae larvae previously referred in Brazil in the genus Phocanema should be reallocated in Pseudoterranova. Nematodes of the genera Anisakis, Contracaecum, Pseudoterranova and Raphidascaris are reported for the first time parasitizing elasmobranchs in Brazil.
Resumo:
New records for helminth species recovered from elasmobranch fishes in Brazil are established. Digenean and acanthocephalan parasites of elasmobranch fishes are reported from the southern coast of Brazil: Otodistomum veliporum (Creplin, 1837) Stafford, 1904 (Digenea: Azygiidae) in the stomach and spiral valve of Dipturus trachydermus and in the spiral valve of Squatina sp. Cystacanths and juveniles of the acanthocephalans Corynosoma australe Johnston, 1937 and Corynosoma sp., in the spiral valve of Squatina sp., Galeorhinus galeus and Hexanchus griseus and in the stomach of Squalus megalops; a juvenile of Gorgorhynchus sp., in the spiral valve of Sphyrna zygaena. Dipturus trachydermus and Squatina sp. are new host records for O. veliporum. Digeneans and acanthocephalans are reported for the first time parasitizing elasmobranch fishes in Brazil.
Resumo:
Specimens of elasmobranch fishes, captured in the states of Paraná and Santa Catarina, of the southern coast off Brazil, represented by three families, four genera, and four species, were parasitized with otobothrioid trypanorhynch cestodes: Heptranchias perlo (Bonnaterre, 1788), Squalus sp. and Carcharhinus signatus (Poey, 1868) were parasitized with Progrillotia dollfusi Carvajal & Rego,1987; Prionace glauca (Linnaeus, 1758) with Molicola horridus (Goodsir, 1841) Dollfus, 1942. Details of internal morphology and/or scolex and/or proglottids surface ultrastructure, that expanded the description of M. horridus, through observations with lightfield, and/or scanning eletronic microscopy, are provided. The known geographical distribution for the species M. horridus is enlarged. P. dollfusi is reported for the first time in elasmobranchs.
Resumo:
The pathology induced by the nematode Camallanus cotti in the aquarium fishes Beta splendens (beta fish) and Poecilia reticulata (guppy) consisted of gross and microscopic lesions, the former characterized by abdominal swelling with reddish parasites protruding from the anus in both fish hosts and the latter, similar in the beta fishes and guppies, by hemorrhage, congestion, edema, a few glandular elements, and extensive erosion areas in the rectum mucosa, with a marked thickening of the wall and absence of inflammatory infiltrate. Lesions were associated with the presence of several worms attached to the wall or free in the rectal lumen. This is the second reference of the parasite in Brazil and the first report of pathological findings related to this nematode species that is also briefly redescribed and illustrated for the first time on the basis of Brazilian samples.
Resumo:
New species of Dilobitarsus Latreille with tetra-tuberculated pronotum (Coleoptera, Elateridae, Agrypninae). Four species of Dilobitarsus Latreille, 1834, D. angulosus sp. nov. (Brazil: São Paulo, Rio de Janeiro), D. bellus sp. nov. (Peru), D. nigrus sp. nov. (Argentina) and D. thoraconstrictus sp. nov. (Bolivia) are described, and D. quadrituberculatus Candèze, 1857 is redescribed. Diagnostic characters of all studied species are illustrated and new records for D. quadrituberculatus are included. A key to Dilobitarsus species from the Neotropical Region is also presented.
Resumo:
Resulting from ion displacement in a solid under pressure, piezoelectricity is an electrical polarization that can be observed in perovskite-type electronic ceramics, such as PbTiO3, which present cubic and tetragonal symmetries at different pressures. The transition between these crystalline phases is determined theoretically through the bulk modulus from the relationship between material energy and volume. However, the change in the material molecular structure is responsible for the piezoelectric effect. In this study, density functional theory calculations using the Becke 3-Parameter-Lee-Yang-Parr hybrid functional were employed to investigate the structure and properties associated with the transition state of the tetragonal-cubic phase change in PbTiO3 material.
Resumo:
Na viagem efetuada à volta do mundo pela U. S. Exploring Expedition mais conhecida pelo nome de Expedição Wilkes e durante o período em que a mesma operava no Atlântico Ocidental, foram visitadas as regiões do Rio de Janeiro e da Patagônia. Por ocasião da festa comemorativa do centenário da The American Philosophical Society, de Filadélfia, ocorrida a 23 de Fevereiro de 1930, o autor teve a oportunidade de apresentar uma nota prévia da qual constava uma lista de peixes capturados durante o cruzeiro da Expedição. Teve, então, o ensejo de examinar o diário redigido pelo Dr. Charles Pickering, botânico da Expedição, nele encontrando anotações valiosas para a História Natural, considerada em seu sentido amplo, detalhes a respeito das localidades percorridas e relações extensas de animais e plantas, além de diversos representantes pertencentes a outros grupos. Sob o ponto de vista histórico, os comentários aí constantes são de importância significativa. Em muitos casos, essas apreciações fornecem base sólida para a efetivação de estudos faunísticos, de caráter comparativo, muito instrutivos e úteis. O autor examinou a coleção de peixes da Expedição Wilkes que se encontra no Museu Nacional dos Estados Unidos, em Washington, acervo esse gentilmente posto à sua disposição para estudo. Dessa maneira, no presente trabalho, fornece matéria de amplo interesse histórico, visando com isso lançar alguma luz sobre a imensa fauna do Brasil e da Argentina. Baseando-se nos dados fornecidos por Pickering, o autor divulga dados curiosos a respeito da baía do Rio de Janeiro e adjacências, no ano de 1838. Segue-se uma lista contendo a diagnose de 82 espécimes de água doce, salobra e salgada, estudados e comparados com outros de várias procedências. Referindo-se ao Rio Negro, descreve o autor o aspeto da região patagônica, durante certo período de 1839, fazendo comentários a respeito de 7 espécies de peixes nela, encontradas.
Resumo:
Neste artigo descrevemos a contaminação acidental de uma cepa de malária de roedor (Plasmodium berghei) por um hemoparasita (Eperythrozoon coccoides), levando a alterações importantes no comportamento da malária experimental. A demonstração do parasita foi feita por microscopia óptica e eletrônica e a fonte de contaminação foi detectada em roedores normalmente utilizados na manutenção da cepa, obtidos do mesmo biotério. As medidas disponíveis para o controle deste tipo de infecção são discutidas propondo se a utilização de tetra-ciclina em matrizes e posterior utilização de animais Fl não tratados. Comenta-se a importância deste tipo de contaminação experimental.
Resumo:
The first register of Biomphalaria straminea, vector species of schistosomiasis, in Santa Catarina State, South Brazil is described. The specimens were obtained from two ornamental aquaria of private residences. In both cases the ornamental plants and/or fishes were bought from the same supplier. The presence of this species was later confirmed in the farm where these plants and fishes are cultivated, in the city of Governador Celso Ramos, also in Santa Catarina State. The occurrence in natural environments was later detected in two different places of the Island of Santa Catarina.
Resumo:
Fishes of family Batrachoididae are responsible for great number of injuries in fishermen in North and Northeast regions of Brazil. The genus Thalassophryne presents various venomous species of fishes found in the Brazilian coast, T. nattereri being the most common of them. The venom is ejected through two hollow spines on the dorsal fin and two on pre-opercular regions, which present a venomous gland in the base and can be erected or depressed by the fish. The manifestations of the envenoming were intense local pain, edema and erythema in 43 patients observed in Salinópolis (Pará State) and Aracaju (Sergipe State). There were no systemic manifestations, but necrosis was detected in eight and bacterial infection in ten injured fishermen. The circumstances of the contacts and therapeutic aspects are discussed. Envenoming by the genus Thalassophryne is important and frequent and should be considered of moderate severity grade, since there are not the excruciating pain or the massive local necrosis provoked by scorpionfishes (Scorpaena) or stingrays injuries nor the systemic manifestations that are the most important marker of severe envenoming.
Resumo:
The present study was undertaken to assess the effect of the crude extract of Cleome droserifolia (CD) leaves on experimentally infected mice with Schistosoma mansoni. Two groups of mice, showing a patent infection of S. mansoni, one of them was daily treated with an alcoholic extract of CD leaves (0.31 g kg-1 body weight, i.p.) for 21 days. The schistosomicidal activity of the CD extract was evaluated, three weeks post-treatment, on some parasitological and histopathological aspects including worm load, oogram pattern, faecal eggs releasing and granuloma formation. In addition, serum thyroid hormones levels (tri-iodothyronine; T3 and tetra-iodo-thyronin; T4), serum total protein contents and hepatic reduced glutathione (GSH) were evaluated. Treatment using CD extract resulted in a weak reduction in worm burden (32.46%) and affected the viability of both mature and immature eggs as indicated by the increase in the percentage of dead eggs and the decrease in the percentage of live ones. In addition, a week post-treatment, eggs elimination was observed in the stool of the infected-treated group which was low compared to the infected group. There was a suppressive effect of the extract on granuloma formation that could be due to the antioxidant effect of the extract. These data are confirmed by increasing hepatic GSH, serum total proteins and thyroid hormone levels in the infected-treated group as compared to the infected group. Treatment significantly enhanced b globulin fractions of the protein. Based on these assumptions, CD extract has beneficial effects on thyroid hormones status and anti-schistosomiasis activity. The beneficial effects of CD extract could be related to its direct effects on the parasite, and secondary to its effect on the antioxidant capacity of the host. The present study could emphasize the precise mechanism (s) of CD extract protection.
Resumo:
Pleurolophocercous cercariae emerged from naturally infected Melanoides tuberculata from Minas Gerais State, Brazil, were used to perform experimental infection of laboratory-reared Poecilia reticulata. Mature metacercariae were obtained from the gills of fishes and force-fed to Mus musculus. The adult parasites which recovered from small intestines of mice were identified as Centrocestus formosanus. This is the first report of M. tuberculata as intermediate host of this heterophyid in Brazil.
Resumo:
INTRODUCTION: The fishes of continental Brazil have socioeconomic importance due to their potential for sport fishing and commercial and subsistence uses, as seen in the Upper Paraguay River Basin, particularly in the municipalities of the Pantanal region, where it is the second largest economic activity. Injuries caused in professional fishermen are common and poorly studied, as in other regions of the country. METHODS: Data were obtained from questionnaires and interviews with 100 professional fishermen, 50 in each municipality, between December 2008 and October 2009. RESULTS: All the fishermen reported some kind of injury caused by fish stings (78% of injuries) and fish, alligator and snake bites (22%) on the hands (46% of cases) and feet (35% of cases). Most of the patients had mild symptoms. The most severe cases were associated with secondary bacterial infections and required specific treatment and prolonged recovery associated with social and economic losses. CONCLUSIONS: The results of this study indicate that the stressful work conditions, inattention to basic preventive measures and carelessness were factors that contributed to accidents and that the toxicity and ability to inflict mechanical trauma of some aquatic species, plus the ineffective use of first aid and hospital treatment, contributed to the high morbidity and complications in many cases. Data from this study are relevant to the fishing communities of the Pantanal region, since they reveal high rates of accidents, lack of knowledge concerning first aid, initial treatment, injury prevention and lack of medical follow-up of the population.