Hematologic study of red pacu (Colossoma brachypomum)

A study of a laboratory population (N = 60) of immature red pacu (Colossoma brachypomum) was conducted for the purpose of characterizing hematological parameters. Median (2.5th - 97.5th percentile) values obtained by hemocytometer counts, spun packed cell volume, refractometer, and differential counts were as follows: packed cell volume 25.8 (22.0 - 32.0) %, total plasma solids 4.0 (3.4 - 4.7) gm/dl, red blood cell concentration 1.68 (1.15 - 2.94) x 10(3) microliter, white blood cell concentration 33.5 (13.6 - 52.3) x 10(3) microliter, heterophils 3.2 (0.3 - 16.8) x 10(3) microliter, non-staining granulocytes 0.4 (0.05 - 1.9) x 10(3) microliter, eosinophils 0.2 (0.1 - 0.3) x 10(3) microliter, lymphocytes 21.0 (8.2 - 35.6) x 10(3) microliter, granular lymphocytes 1.4 (0.4 - 5.6) x 10(3) microliter, and monocytes 1.2 (0.4 - 4.4) x 10(3) microliter. Blood cell measurements were taken and descriptions given of the blood cells encountered on the stained smear A modified leukocyte slide estimate formula [(avg. # leukocytes/10 HPF x 2,000) + 6,3001 (/microliter) had better agreement with Neubauer hemocytometer white cell counts than the method used for avian species.