This study evaluated the haematological parameters of the hybrid surubim (Pseudoplatystoma
corruscans x P. reticulatum) farmed in intensive and semi intensive system. A total
of 240 fish were examined, 120 from fish farm and 120 from a semi-intensive for comparison
between the hot and cold season. The water quality was weekly measured to evaluate
the influence of environmental conditions on the haematology. Fish from intensive
system showed hematocrit and white blood cell count (WBC) higher in hot season while
the total plasmatic protein, hemoglobin concentration, mean corpuscular hemoglobin
concentration (MCHC) and mean corpuscular volume (MCV) were higher in cold season.
In fish from semi intensive system, the red blood cells count (RBC) and total thrombocyte
number was higher in hot season while the MCHC and MCV were higher in cold season.
There was no alterations in the numbers of lymphocytes, neutrophils, basophils, eosinophils
and PAS - positive granular leukocyte (PAS-LG). The results showed the influence of
seasonality on the hematological parameters of the hybrid surubim kept under normal
farming conditions. Regarding water quality, hot season was directly related to increased
water temperature and decreased dissolved oxygen while the opposite was found in cold