Fauna parasitária e relação parasito-hospedeiro de tambaquis criados na região do Baixo São Francisco, nordeste do Brasil / Parasitic fauna and parasite-host relationship of tambaqui reared in São Francisco river basin, Brazilian northeast

Este trabalho teve como objetivo avaliar a fauna parasitária de tambaquis na região do Baixo São Francisco-AL/SE-Brasil e correlacionar os índices de prevalência e intensidade média com fatores bióticos e abióticos. Foram coletados 252 espécimes para análise parasitológica de 10 pisciculturas. Os parasitos foram contabilizados, identificados, e determinaram-se os índices de prevalência e intensidade média, que foram correlacionados com fatores bióticos e abióticos. Dos peixes coletados, 65,5% estavam parasitados por pelo menos um táxon. Foram encontrados 10 táxons: Monogeneas, Ichthyophthirius multifiliis, tricodinídeos, Piscinoodinium pillulare, Ichthyobodo sp., Dolops carvalhoi, Lernaea cyprinacea, Procamallanus (Spirocamallanus) inopinatus, Henneguya sp. e Myxobolus sp. As maiores prevalências foram encontradas para Monogeneas (49,2%) e Myxobolus sp. (31,5%). Correlações negativas entre prevalência e fatores bióticos (peso e comprimento) foram observadas para Monogeneas (r2= -0,49; r2= -0,43), Myxobolus sp. (r²= -0,46; r²= -0,39) e Henneguya sp. (r²= -0,41; r²= -0,39). O fator abiótico temperatura apresentou correlação negativa com as prevalências de Lernaea cyprinacea (r= -0,39) e tricodinídeos (r= -0,33), enquanto a condutividade elétrica apresentou correlação positiva (r= 0,40) com a prevalência de tricodinídeos. Conclui-se que a fauna parasitária dos tambaquis cultivados na região do Baixo São Francisco é diversificada e com a carga parasitária dependente da qualidade de água e do estágio de desenvolvimento dos peixes.(AU)

This study investigated the parasitic fauna of tambaquis reared in lower Sao Francisco region-Al/SE-Brazil correlating parasitic indices to abiotic and biotic factors. A total of 252 specimens of tambaqui were collected in ten fish farms for parasitological analysis. The parasites were counted, identified and the parasitological indices were determined and correlated to biotic and abiotic factors. Of all collected fish, 65,5 % were parasitized by at least one taxon. Ten taxa were found: Monogeneans, Ichthyophthirius multifiliis, trichodinids Piscinoodinium pillulare, Ichthyobodo sp, Dolops carvalhoi, Lernaea cyprinacea, Procamallanus (Spirocamallanus) inopinatus, Henneguya sp. and Myxobolus sp. The higher prevalences were found to monogeneans (49.2%) and Myxobolus sp. (31.5%). Negative correlation of prevalence and biotic factor (weight and length) were observed to monogeneans (r 2 = -0.49, r 2 = -0.43), Myxobolus sp (r²= -0.46; r²= -0.39) and Henneguya sp (r²= -0.41; r²= -0.39). Abiotic factor of temperature presented a negative correlation to prevalence of Lernaea cyprinacea and trichodinids (r= -0.39 e r= -0.33, respectively) and the electric conductivity presented positive correlation to trichodinids (r= 0.40). It was concluded that parasitic fauna of tambaquis cultured in Lower São Francisco region is diversified and the parasitic load dependent on water parameters and fish growth.(AU)

Haematological and histopathological analysis in South American fish Piaractus mesopotamicus parasitized by monogenean (Dactylogyridae).

Monogeneans are the parasites mostly found on the body surface and gills of fish and can cause large losses in farmed fish. Some studies demonstrate elevated parasitic levels causing hematological alterations. But few of them relate the effects of parasitism on the hematology and histopathology of native freshwater farmed fish. This study evaluated the host-parasite relationship in pacu (Piaractus mesopotamicus) parasitized by the monogenean Anacanthorus penilabiatus. Hematological and parasitological assessments were obtained in 60 fish captured in a fish farm located in Dourados, State of Mato Grosso do Sul, Central Brazil. Fish were analyzed in different categories of parasite number: class I (n=13; 0-200 parasites), class II (n=17; 201-1200 parasites); class III (n=7; 1201-2200 parasites); and class IV (n=23; more than 2200 parasites per host). The highest levels of parasitism caused significant decrease (p<0.05) in the hematocrit, red blood cells (RBC), mean hemoglobin concentration (MCHC) and basophils number. Thrombocytes, mean corpuscular volume (MCV), mean corpuscular hemoglobin concentration (MCHC), monocytes, eosinophils, neutrophils and LG-PAS did not present significant difference among the parasitic levels. In contrast, increased number of total leukocytes and lymphocytes were found in highly-parasitized fish. A positive linear correlation (p<0.01) was found between the amount of parasites and fish weight. Histopathology revealed severe hyperplasia, sub-epithelial edema, fusion of the secondary lamellae, focal and multifocal necrosis in highly parasitized fish.

Paratrichodina africana (Ciliophora): a pathogenic gill parasite in farmed Nile tilapia.

Trichodinids are ciliated protozoa that are widely known as one of the main groups of fish parasites. The genus Trichodina presents the greatest species diversity. However, records of Paratrichodina species are scarce, and little is known about their pathogenicity in hosts. The present study provides new records of Paratrichodina africana Kazubski and El-Tantawy (1986) in Nile tilapia from South America and descriptions of pathological changes and seasonality. A total of 304 farmed fish were examined. From gill scraping, parasites were identified using Klein's nitrate impregnation method. Gill samples were fixed for histopathological analysis. Small trichodinid found in this study have a prominent blade apophysis and narrow central part and blade shape that corresponds to the characteristics of P. africana Kazubski and El-Tantawy (1986). Gill lesions were proportional to parasite intensity, in which the gill tissue was compromised in heavy infestation. Proliferative disturbances were found, including epithelial hyperplasia, desquamation, and mononuclear and eosinophilic infiltrate that culminated in necrosis. We did not observe a seasonality effect on the occurrence of P. africana. This ciliated protozoan causes compromised respiratory capacity that leads to severe gill lesions and currently is an important pathogen that afflicts intensive tilapia cultures in Brazil.

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.

Isolamento e identificaçäo da microbiota fúngica e de dermatófitos da pele de equinos hígidos e daqueles afetados por dermatofitose / Isolation and identification of fungal microbiota and of dermatophytes from healthy horses and from dermatophytosis-affected horses

Pela inexistência na literatura latino-americana e brasileira de trabalhos que enfoquem a microbiota fúngica de equinos hígidos e as principais espécies de dermatófitos em casos de equinos com lesöes sugestivas de infecçäo dermatofítica do tegumento cutâneo, utilizaram-se 175 equinos, de ambos os sexos, tanto de raça definida como daqueles sem perfeita condiçäo racial, de diferentes idades e que foram reunidos em 2 grupos. O GRUPO I composto de 133 equinos assintomáticos e desprovidos de lesöes cutâneas, dos quais, após exame dermatológico, interposiçäo da Luz de Wood (48 equinos), colheram-se, pela técnica do carpete, material que foi semeado em meios de ágar Sabouraud Dextrose, Mycobiotic ágar, Tricophyton ágar 3, Tricophyton ágar 5 e incubados a 25§ e 37§C durante 30 dias. Isolaram-se: Penicillium sp (80,4 por cento), Rhizopus sp (62,4 por cento), Aspergillus sp (41,3 por cento), Fusarium sp (40,6 por cento), Cladosporium sp (33,1 por cento), Trichoderma sp (21,0 por cento), Mucor sp (18,0 por cento), Epicoccum sp (12,0 por cento), Mycelia sterillia (8,8 por cento), Rhodotorula sp (2,2 por cento), Neurospora sp (4,5 por cento), Alternaria sp (3,7 por cento), Aureobasidium sp (3,7 por cento), Geotrichum sp (3,0 por cento), Paecilomyces sp (2,0 por cento), Monascus sp (2,2 por cento), Cephalosporium sp (1,5 por cento), Nigrospora sp (0,7 por cento), Scopulariopsis brevicaulis (0,7 por cento), Trichosporun sp (0,7 por cento). O GRUPO II foi composto por 42 equinos portadores de lesöes sugestivas de dermatofitose que, após terem sido submetidos a exame dermatológico, expostos à luz de Wood (22 equinos), tiveram pelame e crostas submetidos a cultivo micológico, isolando-se em 6 (14,3 por cento) cepas de Dermatophylus congolensis e em 3 (7,1 por cento) equinos houve o crescimento de dermatófitos da espécie Microsporum canis. Dos 70 equinos expostos à radiaçäo ultravioleta observou-se falsa fluorescência em 2 animais