INFLUENCE OF THERMAL STRESS ON THE HEMATOLOGICAL PROFILE OF ONCORHYNCHUS MYKISS HELD IN DIFFERENT STOCKING DENSITIES IN RECIRCULATING AQUACULTURE SYSTEMS
Angelica Docan, V. Cristea, Lorena Dediu
Hematological indices are important parameters for the evaluation of fish physiological status. The aim of present study was to obtain a basic knowledge of the hematological response of Oncorhynchus mykiss maintained in different technological condition induced by stocking density and temperature. Specimens belonging to two experimental groups had individual weights of 494.34 ± 83.19 g respectively 558.04 ± 46.51 g and the stocking density was 41 kg/m3 respectively 28 kg/m3.The sampling of Oncorhynchus mykiss blood from the four variants before and after the experimental trial allowed determination of hematological indices. Red blood cell counts (RBCc), hematocrit values (Hct), hemoglobin concentration (Hb), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH) and mean corpuscular hemoglobin concentration (MCHC) were measured and analyzed, with routine methods used in fish hematology. Differences in hematological parameters were statistically analyzed by Student T test. Physiological stress, induced by maintenance in different technological condition induced by thermal stress, was reflected in the hematological indices (significant increase, p<0.05, RBCc, Hb, Ht, MCV and decrease insignificant, p >0.05 MCH, MCHC) with direct implications at the biotechnological level.
Key words: Oncorhynchus mykiss, stocking density, thermal stress, hematological indices