Trichodina heterodentata (Ciliophora: Trichodinidae): a new parasite for Piaractus mesopotamicus (Pisces: Characidae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Trichodina colisae (Ciliophora: Trichodinidae): new parasite records for two freshwater fish species farmed in Brazil

Tricodinídeos são protozoários ciliados móveis com ampla distribuição mundial; são considerados um dos agentes parasitários que mais acometem peixes cultivados. No Brasil, a maioria dos tricodinídeos que parasitam importantes espécies de peixes cultivados são desconhecidos, o que requer mais estudos taxonômicos com esse grupo de parasitos. Este estudo caracteriza morfologicamente Trichodina colisae Asmat & Sultana, 2005 de pacu (Piaractus mesopotamicus) e do híbrido patinga (P. mesopotamicus × P. brachypomus) cultivados, respectivamente, no Centro-Oeste e Sudeste do Brasil. Foram feitas montagens a fresco do raspado de muco da pele, nadadeiras e brânquias, fixados com metanol e, posteriormente, impregnados com nitrato de prata e coradas com Giemsa para avaliação em microscopia óptica. O presente estudo relata não só a segunda ocorrência de T. colisae no mundo, mas também a primeira ocorrência na América do Sul.

Metodologia de infecção experimental e grau de susceptibilidade do híbrido tambacu e Leporinus macrocephalus Garavello & Britski (Osteichthyes, Anostomidae) a quatro inóculos de trofozoítos de Icthyophthirius multifiliis Fouquet (Protozoa, Ciliophora)

Tropical fishes like Leporinus macrocephalus Garavello & Britski, 1988 (piauçu) and the hybrid tambacu (Piaractus mesopotamicus Holmberg, 1887 pacu male x Colossoma macropomum Cuvier, 1818 tambaqui female) were experimentally infected with four inocula of trophonts of Ichthyophthirius multifiliis Fouquet, 1876 (Protozoa, Ciliophora) and the infection level was evaluated. Each one of twelve experimental units consisted of a tank with 200 liters of water and two specimens of each kind of fish. The following treatments were designed to each tank, in triplicate: 8, 16,32 and 64 trophonts. After 8 days of exposure the fishes were killed and the number of trophonts was counted at a stereoscopic microscope. This assay showed to be feasible at tropical conditions and was able to show that tambacu was more susceptiblc than piauçu.

FIRST RECORD of AN EPIBIONT PROTOZOAN EPISTYLIS SP (CILIOPHORA, PERITRICHIA) ATTACHED TO AMPLEXIBRANCHIUS BRYCONIS THATCHER & PAREDES, 1985 (COPEPODA, ERGASILIDAE) FROM PEIXE'S RIVER, STATE of São Paulo, BRAZIL

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

Brazilian catfish parasitized by Epistylis sp. (Ciliophora, Epistylididae), with description of parasite intensity score

The determination of mean intensity of parasitism for colony-forming sessile protozoan such as Epistylis has been a great problem in parasitological studies. Some alternatives have been proposed by researchers for laboratory and field conditions. This study describes the criteria to establish the parasitic intensity score for epistylidid infestation in fish. Parasite distribution and the host-parasite relationship in four species of Brazilian cultured catfish and their hybrids are discussed. The highest prevalence rates were found in the hybrid jundiara, Leiarius marmoratus male × Pseudoplatystoma reticulatum female (96.4 %), followed by jurupoca, Hemisorubim platyrhynchos (60 %), and the hybrid surubim, Pseudoplatystoma corruscans male × P. reticulatum female (52.7 %). Positive correlation between parasitic intensity score and the fish size, weight, and relative condition factor were also observed. These findings indicate that Epistylis infestation in Brazilian catfish is an emerging disease in cultured fish. © 2012 Springer-Verlag.

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.

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. © 2013 Elsevier B.V.

Trichodina heterodentata (Ciliophora) infestation on Prochilodus lineatus larvae: a host-parasite relationship study

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

First record of an epibiont protozoan Epistylis sp (Ciliophora, Peritrichia) attached to Ergasilus chelangulatus (Ergasilidae) in Brazil

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

Haematological and gill responses in parasitized tilapia from valley of Tijucas River, SC, Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Rumen microbial diversity under influence of a polyclonal antibody preparation against lactate-producing and proteolytic bacteria in cows fed different energy sources

Nine ruminally cannulated cows fed different energy sources were used to evaluate an avianderived polyclonal antibody preparation against specific ruminal bacteria and monensin on microbial community diversity. The experimental design was three Latin squares 3 x 3 distinguished by the main energy source in the diet [dry-ground corn grain, high moisture corn silage or citrus pulp]. Inside each Latin square, animals received one of the feed additives per period [control, monensin or polyclonal antibody preparation]. Each period lasted 21 days where 20 were used for treatments adaptation and the last one for sampling collection. Microbial diversity was evaluated by protozoa counts and denaturing gradient gel electrophoresis. Polyclonal antibodies plus citrus pulp (CiPu) addition in the diet resulted in an increase of relative counting of Isotricha protozoa that indicates a possible effect on this ruminal ciliate population. In general lines, in the present experiment, it was not possible to assign that there was a pattern in the structures of amplification of Bacteria and Archaea communities of the ruminal content. Oral passive immunization is a technology that arises as an effective alternative for feed additive production. Further research is still necessary to better understand its mechanisms of action.

Avaliação de protozoários em tilápias (Oreochromis niloticus) e possíveis riscos em saúde pública

Pós-graduação em Medicina Veterinária - FMVZ

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.