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ABSTRACT. Parasitic fauna of cultivated fishes in feefishing farm ofFranca, São Paulo State, Brazil. I. Protozoans. The present work studied protozoan parasites of cultivated fishes (N = 433) from two feefishing fal111 situated in Franca, São Paulo, Brazil, during a period of April 1997 through March 1999. Specimens of piauçú Leporinus macrocephalus Garavello & Britski, 1988 (Anostomidae) o sistema de cultivo intensivo, usualmente praticado pelas pisciculturas industriais, caracteriza-se pelo aumento da densidade de estocagem de peixes, visando a máxima produção. Assim, nesse tipo de exploração comercial, surgem com freqüência problemas relativos ao manejo inadequado, às questões nutricionais e às enfermidades infecciosas e parasitárias (THATCHER &

Four species of Serrasalmidae, one Characidae, one Cichlidae, one Cynodontidae, one Curimatidae, one Acestrorhynchidae and one Sciaenidae were recorded as new hosts for B. patagonica in the Amazon. This study indicates a low intensity and low parasitic specificity of B. patagonica, and also recorded the first parasitism by this ectoparasite in farmed Colossoma macropomum, describing its highly pathogenic effect.

Objective. This study describes the parasitic fauna and relative condition factor (Kn) in Nile tilapia Oreochromis niloticus L. (Cichlidae) from fish farms in the State of Amapá. Material and methods. 123 fish from four fish farms in the state of Amapá, Brazil were necropsied for parasitological and Kn analysis. Results. 64.2% of the examined fish, had the gills infected with Cichlidogyrus tilapiae Paperna, 1960 (Monogenoidea: Dactylogyridae); Ichthyophthirius multifiliis Fouquet, 1876 (Protozoa: Ciliophora), Trichodina Ehrenberg, 1830 and Paratrichodina africana Kazubski & El-Tantawy, 1986 (Protozoa: Trichodinidae). The highest prevalence found corresponded to Monogenoidea C. tilapiae while the lowest corresponded to Trichodinidae. However, I. multifiliis was the parasite that presented the greatest intensity and abundance. The differences found in the infection rates of the different fish farms due to causes further discussed. The parasitism did not influence the relative condition factor (Kn) of fish. This was the first record of P. africana in Brazil and occurred in the Eastern Amazon. Conclusions. In Brazil, Lamproglena sp. is an emerging parasite in the Southern and Southeastern regions, but this crustacean was not found in the Nile tilapia in the State of Amapá. The parasitic infections in Nile tilapia farmed in Brazil are caused by protozoan, monogenoidea, crustacea and digenea species, and the regional differences on their prevalence and intensity rates are discussed in this study.

ABSTRACT. Hepatosomatic and splenosomatic relation ofintensively cultivated teleost fishes. The mean values of hepatosomatic relation (HSR), splenosomatic relation (SSR) and relative condition factor (Kn) in Nile tilapia (Oreochromis ni/oticus Trewavas, 1983); pacu (Piarac/us mesopo/amicus Holmberg, 1887); piauçu (Leporinus mac/'ocepha/us Garavello & Britski, 1988) and tambacu hybrid (P. mesopo/amicus male x C%ssoma macropomum Cuvier, 1818 female) are described. The experiment was carried out fl'Om feefishing farm situated in Franca, São Paulo State, Brazil. Nile tilapia showed the greatest HSR compared to pacu, piauçu and tambacu. Although, in the last three fishes the relation was similar. The SSR between tilapia and piausu was similar, but smaller than observed in pacu and tambacu. Nevertheless, SSR in pacu and tambacu was different. The hepatic weightlbody weigth relation and hepatic weightlbody length relation presented positive correlation in ali studied fishes. The splenic weight/body weigth relation and splenic weightlbody length relation were not significant (P>O.05) in Nile tilapia, pacu and tambacu, but highly significant in piauçu (P