Resposta fisiológica à infestação experimental com Ichthyophthirius multifiliis (Fouquet, 1876) em alevinos de jundiá (Rhamdia quelen Quoy e Gaimard, 1824) previamente alimentados com diferentes fontes lipídicas

Abstract

RESUMOUm fator limitante nas primeiras fases do cultivo do jundiá (Rhamdia quelen Quoy e Gaimard, 1824) é a presença da ictioftiríase. Os ácidos graxos poliinsaturados (PUFAs) presentes na dieta possuem uma potente atividade imunomoduladora, e esta atividade depende da espécie analisada e da quantidade/qualidade dos PUFAs da dieta. O objetivo do presente estudo foi avaliar a resposta fisiológica de alevinos de jundiá, alimentados com diferentes fontes de ácidos graxos, quando parasitados pelo protozoário Ichthyophthirius multifiliis (Fouquet, 1876 A limiting factor in the early stage of the jundiá (Rhamdia quelen Quoy; Gaimard, 1824) culture is the presence of diseases such as ichthyophthiriasis or "Ich". Dietary polyunsaturated fatty acids (PUFAs) have a potent immunomodulatory activity; and this activity depend of the fish species, quantity/quality of the dietary PUFAS. The aim of this study was evaluate the physiologic response of jundiá, rather fed diets with different sources of fatty acids when challenge to Ich disease. Fingerlings of jundiá (7.6±0.8g) were fed during seven weeks with five diets with a different lipid source: fish, linseed and corn oils. Then, the fish were challenged with the Ichthyophthirius multifiliis (Fouquet, 1876). On the 5 th day, the presence of the disease was detected. Survival rate, blood samples and infection grade were recorded. Diets affect the survival rate of fingerlings, thus fish fed with diet with fish oil showed a higher survival. Hematocrit and infestation grade no recorder differences among treatment. The differential analysis of white blood cells shows difference. The results point out, at first time in jundiá, that dietary lipids caused diversity physiologic response, this may be represent an opportunity for the disease treatment. New studies must be carrying out to deep knowledge found.