Triploidy in the hematology of jundia juveniles (Siluriformes: Heptapteridae)

This study compared the hematological characteristics of diploid and triploid of jundia, Rhamdia quelen juveniles, an important freshwater fish cultured in south Brazil. Hematological morphometry of erythrocytes were determined in blood smears under a light microscope. The blood was used to measure the number of red blood cells (RBC) with a hemocytometer Neubauer chamber, and the numbers of white blood cells (WBC) and thrombocytes that were obtained using an indirect method. The results showed that triploidy increased (p < 0.01) the size and volume of the erythrocytes. Nevertheless, as expected, triploidy decreased (p < 0.01) the number of circulating erythrocytes, leucocytes and trombocytes in the blood of jundia. Moreover differential cell counts were different in diploids and triploids, suggesting that triploidy affects the number of cells and their proportion in blood. Lymphocytes were the most predominant cells in the differential counting of diploid fish (62.5%) while monocytes were predominant in triploid fish (49.6%). These results suggest performance differences between ploidies of jundia, and require future studies to evaluate the potential of triploid jundia in the culture conditions and resistance to infection.