Hematological evaluation in commercial fish species from the floodplain of the upper Paraná River, Brazil

Abstract

In February 1994 and in March 1995 one hundred and forty-four four specimens of teleosts were analyzed. They belonged to the 20 most representative species from the Paraná River basin, state of Paraná and Mato Grosso do Sul, Brazil. Blood samples were collected from caudal peduncle to determine the number of erythrocytes (Er), hematocrit (Ht), hemoglobin rate (Hb) and differential percentage of leukocytes. Total hematometric indexes (mean corpuscle volume, mean corpuscle hemoglobin and mean corpuscular hemoglobin concentration) were estimated. Hematological parameters related to sex and gonadal maturation stages were undertaken for Prochilodus lineatus and Schizodon borellii. In these species significant differences between the gonadal maturation stages, with lowest values in the resting stage were found. Lymphocytes, monocytes, neutrophils, basophils, eosinophils, special granulocytic cells and immature cells were registered in the leukocyte differential count. As a general rule, neutrophil, followed by lymphocytes, was the most frequent cell recorded in the peripheral blood of most species. High percentage of eosinophils in the peripheral blood of some Siluriforms was observed.