Nenneguya garavelli n. sp and Myxobolus peculiaris n. sp (Myxozoa : Myxobolidae) in the gills of Cyphocharax nagelli (Osteichthyes : Curimatidae) from Rio do Peixe Reservoir, Sao Jose do Rio Pardo, São Paulo, Brazil

The present work describes myxozoans found in Cyphocharax nagelli (Characiformes: Curimatinae) commonly called saguiru collected from Rio do Peixe Reservoir, Sao Jose do Rio Pardo, São Paulo, Brazil. From a total of 38 examined fish, 24 were infected with Henneguya garavelli n. sp. (63% prevalence) and two with Myxobolus peculiaris n. sp. (5% prevalence) in the gills. Spores were studied by staining and fresh spores were observed by differential interference contrast optics. Henneguya garavelli n. sp. differs from Henneguya iheringi , Henneguya occulta, Henneguya cesarpintoi, Henneguya santae, Henneguya pisciforme, Henneguya amazonica, Henneguya striolata, Henneguya leporinicola and Henneguya chydadea in spore length and from Henneguya travassosi, Henneguya adherens, Henneguya malabarica, Henneguya piaractus and also Henneguya chydadea in polar capsule length and tail length. Myxobolus peculiaris n. sp. was very different when compared to other species of Myxobolus in its morphology and the biggest size of spore body. The authors present tables with comparative measurements of Brazilian myxozoan parasites. (c) 2006 Elsevier B.V. All rights reserved.

Gill infection of Leporinus macrocephalus Garavello & Britski, 1988 (Osteichthyes: Anostomidae) by Henneguya leporinicola n. sp. (Myxozoa: Myxobolidae). Description, histopathology and treatment

Piauçus (Leporinus macrocephalus) criados em viveiro de 300 m² (densidade de 10 peixes/m²) apresentavam sinais de asfixia e mortalidade diária de 27 peixes. Exemplares com 8 cm em média foram examinados quanto à presença de lesões e seus possíveis agentes. Muco da superfície corporal e fragmentos de órgãos foram colhidos e examinados à microscopia de luz, em esfregaços a fresco ou corados ou em cortes histológicos. O exame dos esfregaços mostrou a presença de inúmeros esporos entre as lamelas secundárias dos filamentos branquiais, identificados como Henneguya leporinicola n.sp (Myxozoa: Myxobolidae). À histopatologia verificou-se marcada hiperplasia epitelial com preenchimento dos espaços entre as lamelas secundárias, congestão e teleangiectasia sinusoidal. Observou-se ainda hiperplasia de células caliciformes e inúmeros cistos do parasito, com até 70,3 mim de diâmetro, localizados entre as lamelas secundárias, recobertos ou não pelo epitélio hiperplásico. Estabelecido o diagnóstico foram realizadas três aplicações de formalina na dose de 10 ml/m³ de água. Após 15 dias da última dose do tratamento, os peixes foram novamente examinados, constatando-se a eficácia das medidas adotadas para interromper a mortalidade, a enfermidade e combater o parasitismo. As únicas alterações teciduais presentes nas brânquias nesse último exame foram moderada congestão sinusoidal e discreta hiperplasia epitelial na base das lamelas secundárias.

Henneguya piaractus n.sp. (Myxozoa: Myxobolidae), a gill parasite of Piaractus mesopotamicus Holmberg, 1887 (Osteichthyes: characidae), in Brazil

Henneguya piaractus n.sp. was found from the gill filaments of Piaractus mesopotamicus (Characidae). Fishes were collected during a year from the reservoir at Centro de Aquicultura da UNESP, Jaboticabal, SP, Brazil. The prevalence of this parasite was 97.3% in the gills of farmed fish. Observations on spore development into the cysts were done. Studies with scanning electon microscopy were performed to observe the spore and cyst structure.

Henneguya nagelii n. sp. (Myxozoa: Myxobolidae) in Cyphocharax nagelii (Steindachner, 1881) (Teleostei: Characiformes: Curimatidae) from the Peixe's River, São Paulo State, Brazil

A new species of Myxosporea, Henneguya nagelii n. sp., is described parasitizing the gills of Cyphocharax nagelii collected from Peixe's River, São Paulo State, Brazil. Among the fish examined, 16.7 % had gills parasitized by myxosporeans. The plasmodia were white, round, or oval and measured 150-250 μm. The mature spores were fusiform and had smooth wall. The spores measurements were the following: total length, 34.5 ± 4.2 (26.4-39.9) μm; body length, 12.0 ± 0.5 (11.2-11.9) μm; body width, 4.9 ± 0.3 (4.4-5.5) μm; and caudal process length, 22.4 ± 4.0 (14.7-27.3) μm. The polar capsules were elongated and of unequal size, with lengths of 4.9 ± 0.4 (4.0-5.9) μm and 5.2 ± 0.4 (4.6-6.0) μm for the longest and shortest axes, respectively. Capsule width was 1.8 ± 0.2 (1.5-2.2) μm. Each capsule contained a polar filament with six to eight turns. There was no mucous envelope or iodinophilous vacuole. Morphometric differences between this parasite and other species of the genus Henneguya indicated that the parasite observed in C. nagelii is a new species. This is the first species of Myxosporea described in Peixe's River. © 2013 Springer-Verlag Berlin Heidelberg.

Estudo dos mixozoários (Myxozoa : Myxosporea) parasitos dos peixes characiformes Acestrorhynchus lacustris (Lütken, 1875) e Steindachnerina insculpta (Fernández-Yépez, 1948) coletados no Rio do Peixe, médio Rio Tietê, SP, Brasil

The São Paulo State has as one of its main rivers the Tietê, which is an extremely important source because of its biodiversity, use in navigation and mainly as direct supplier of water for thousands of people in the region. Currently, the biodiversity of marine and freshwater ecosystems has been threatened, primarily by environmental problems resulting from the degradation of ecosystems, an example is the stretch of the Middle Tietê River, where the Barra Bonita dam (SP) focused virtually the whole load organic effluents from the metropolitan region of São Paulo, leading to eutrophication with the loss of water quality. This basin is located in the Peixe’s River, a tributary of the Barra Bonita whose sources are on the slopes of the Cuesta de Botucatu, presenting an altitudinal gradient in a good state of conservation and water quality. From another perspective, the studies related to parasites and other pathogens of aquatic organisms have considerably increased the relevance, especially those hosts with potential for growing and marketing, given the significant increase these activities in Brazil and worldwide. Among the agents responsible for diseases in fish are the myxosporean, which can cause major economic damage, with high mortality ratios. Based on the above, this study evaluated the biodiversity of myxosporean parasites of two species of fish Acestrorhynchus lacustris and Steindachnerina insculpta. During the period January to November 2012, 40 specimens of Acestrorhynchus lacustris and 33 specimens of Steindachnerina insculpta were collected from the Peoxe’s river at four different points. The necropsies were performed and all organs were analyzed looking for myxosporean. Only the species Steindachnerina insculpta had their gills parasitized by two species of the genus Henneguya

Análises morfológicas dos mixozoários (MYXOZOA) parasitos presentes em tecido nervoso de peixes coletados no Rio do Peixe, médio Rio Tietê, SP, Brasil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Morphological aspects of Henneguya aequidens n. sp (Myxozoa: Myxobolidae) in Aequidens plagiozonatus Kullander, 1984 (Teleostei: Cichlidae) in the Amazon region, Brazil

A new species of Myxosporea, Henneguya aequidens sp. n. (Myxozoa: Myxobolidae), was described based on its ultrastructural features. This is a parasite of the freshwater fish Aequidens plagiozonatus, in the Peixe-boi River, Para, Brazil. This parasite was found in the gills, in the form of whitish ellipsoid cysts with mature spores inside them. The average spore body was 15 +/- 0.9 mu m in length (n = 30) and 6 +/- 0.8 mu m in width (n = 30), and the tail measured 27 +/- 0.5 mu m in length (n = 15). The spores showed typical features of the genus Henneguya with two valves of equal size and two symmetrical polar capsules of 3 +/- 0.3 mu m in length and 2 +/- 0.3 mu m in width. Each polar capsule had a polar filament forming a helix from the apical region to the polar caps, with four to six turns. Based on the ultrastructural differences in morphology of these spores, the location of the parasite, and its host specificity, this parasite was described as a new species.

Comparative evaluation of the susceptibility of cultivated fishes to the natural infection with myxosporean parasites and tissue changes in the host

O objetivo deste estudo foi avaliar a susceptibilidade de 4 importantes peixes cultivados a parasitos esporozoários. Os peixes foram coletados bimestralmente de um tanque de cultivo, durante 1 ano. Myxobolus colossomatis e Henneguya piaractus foram encontrados nos órgãos internos e brânquias, respectivamente. A incidência de ambos os parasitos foi de 97,3% em pacu (Piaractus mesopotamicus), 33,3% no híbrido tambacu (Piaractus mesopotamicus x Colossoma macropomum), 5,6% em tambaqui (Colossoma macropomum) e 0% em carpa (Cyprinus carpio). Pacu foi o peixe mais susceptível, encontrando-se parasitado 79,2% nas brânquias, 66,7% nos rins e 50% no baço. A análise histopatológica das brânquias mostrou hemorragias, reação inflamatória com células mononucleares, fibroblastos e hiperplasia das células basais e mucosas.

Phylogeny, ultrastructure, histopathology and prevalence of Myxobolus oliveirai sp. nov., a parasite of Brycon hilarii (Characidae) in the Pantanal wetland, Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Myxobolus cordeiroi n. sp., a parasite of Zungaro jahu (Siluriformes: Pimelodiade) from Brazilian Pantanal: Morphology, phylogeny and histopathology

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

First record of chilodonella hexasticha (ciliophora: Chilodonellidae) in brazilian cultured fish: A morphological and pathological assessment

Chilodonelids are small ciliated protozoans found worldwide and can be dangerous in culture conditions. This study presents morphometric data on the ciliate Chilodonella that is found in cultured Nile tilapia (Oreochromis niloticus), native bait fish tuvira (Gymnotus aff. inaequilabiatus) and native pacu (Piaractus mesopotamicus) and includes a histopathological assessment of the changes that occur in the pacu. For parasitic diagnosis, skin and gill samples were scraped onto slides, dried at room temperature, stained with Giemsa or impregnated with silver nitrate, and the measurements were obtained from photomicrographs. In the diseased pacu, the first gill arch was collected and fixed in a 10% buffered formalin solution for histopathological analysis. Parasite specimens from the different collection sites were identified morphologically as C. hexasticha Kiernik (1909). Diseased fish exhibited depigmentation, skin ulceration, scale loss, excessive mucus production and gill lesions. Histopathological analysis of pacu gills displayed epithelial proliferation with mononuclear inflammatory infiltrate, hemorrhages, and scattering necrosis. In Brazilian-farmed fish this is the first record of C. hexasticha, which has great pathogenic potential in cultured freshwater species. In addition, two new hosts are presented. © 2012 Elsevier B.V.

Infecções parasitárias e microbianas na produção do pacu Piaractus mesopotamicus e do híbrido patinga procedentes da região noroeste do Estado de São Paulo

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Parasitic infections of Piaractus mesopotamicus and hybrid (P. mesopotamicus x Piaractus brachypomus) cultured in Brazil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Parasitofauna de cachara cultivado em tanque-rede no rio Paraguai

The objective of this work was to describe the parasitic fauna of cachara (Pseudoplatystoma reticulatum) cultured in a net-cage in the Paraguai River, Brazil. Ten fish with mean weight of 598.0±81.3 g and total length of 38.6±1.6 cm were examined. All necropsied fish were parasitized by at least two species. Among them, Ichthyophthirius multifiliis (Ciliophora), Myxobolus sp. and Henneguya sp. (Myxozoa), Monogenoidea, Choanoscolex abscissus and Nominoscolex sudobim (Cestoda), Dolops carvalhoi (Crustacea), and Digenea were diagnosed. The protozoan Ichthyophthirius multifiliis was the most prevalent parasite.