Perfil hematológico de tilápias (Oreochromis niloticus) cultivadas em Pernambuco

Abstract

The environmental changes during fish culture reflect directly in the animal health, so the physiologic state should be evaluated systematically. It’s important to assess the animal health during whole culture, making possible an intervention as fast as necessary when any anomaly be detected. The hematological exams are an important tools to diagnose early symptoms. The aim of this study was to investigate the hematological reference values for Nile tilapia, Oreochromis niloticus (Cichlidae), cultured in Pernambuco. Were analyzed 109 fishes with weight and length mean of 525g and 27.7cm. Were determined the hematocrit, red blood cells (RBC); white blood cells (WBC); total thrombocyte; differential count of leukocytes expressed in relative and absolute values; hemoglobin concentration; mean corpuscular volume (MCV); mean corpuscular hemoglobin concentration (MCHC) and mean corpuscular hemoglobin (MCH). When evaluated separately the fishes from two different groups according to the culture technique (pond or cage), great heterogeneity was observed between the two groups. The mean value of RBC from tilapia cultured in ponds was 2.14x106/μL and in cages was 1.86x106/μL, being around 15% greater. The mean value of hemoglobin and hematocrit were, respectively, 16.87% and 26.14% greater in the pond cultured fish. Was verified difference (P<0.05) in the mean values of total thrombocyte, WBC and lymphocyte/μL, that were respectively 34.83%, 38.55%, 33.28% greater in tilapia cultured in ponds. These differences demonstrate that generic parameters to tilapia hematology must be used with caution, try when possible to establish specific values to the target population, using as reference in sanity accompaniment.