Silver catfish is a species of economic interest for the southern Rio Grande do Sul region, Brazil, being well adapted to different environments and artificial diets, showing easy management and good commercial acceptance. Good nutritional status is a determinant factor in fish development. Difference in formation of blood cells is dependent of diet manipulation. The objective of this study was to evaluate the effect of a diet with different protein levels on erythrocytic parameters of silver catfish. Ninety (90) fish were used with an average standard length of 20.01±1.28cm and average weight of 131.4±25.9g distributed in three 1,000L tanks, containing three baskets (80L) each, with three levels of crude protein (30, 40 and 50%). Animals were sampled every two weeks during 45 days. After anesthetization blood was collected through caudal puncture using needle and syringe containing EDTA at 10%. Blood analyses corresponding to the erythrocyte series were performed through automatic counter. Proteic level of diet influences erythrocytic parameters, especially the total number of erythrocytes, hemoglobin rate and hematocrit. The level of 50% CP showed best stimulation of erythropoiesis.
erythrocytes; nutrition; Pimelodidae; protein
