The Influence of Season Variation on Hematological Parameters and Oxidative Stress for Rainbow Trout (Oncorhynchus mykiss)

Abstract

The parameters studied were RBC, Ht, Hb, erythrocyte index MCV, MCH, MCHC, and oxidative stress through SOD and GPx. For each parameter, blood samples were collected at specimens weighing between 100-140g in the summer season, 250-280 g in the fall, 270-300g in the winter and 320-350g in the spring. At the specimens studied the highest values of GPx and SOD were recorded in the spring season due to the stress caused by massive precipitation. During the study, the water temperature ranged between 5.1° C in winter and 19.2° C in summer and O 2 ranged between 8.30 mg/l in the summer and 10.20 mg / l in winter. For most parameters, the highest values were recorded in the spring season and the lowest in the summer season. The data obtained in each season on Oncorhynchus mykiss species do not indicate pathological conditions but more an adaptive fish response to environmental conditions and can serve as a database for future research on welfare of salmonids.

Multi-Approach Assessment for Stress Evaluation in Rainbow Trout Females, Oncorhynchus mykiss (Walbaum, 1792) from Three Different Farms during the Summer Season

“…The MCH value is influenced by the stage of development of a fish (i.e., fry, juvenile, adult) and is also influenced by the water temperature. According to other studies, the normal values of MCH recorded are between 23.16 and 68.06 pg [ 49 , 51 ]. Since MCHCs were not significantly different between months and farms, there is nothing to suggest that there was a higher contribution of immature red blood cells in the groups.…”

Impact of chronic exposure of rainbow trout, Oncorhynchus mykiss, to low doses of glyphosate or glyphosate-based herbicides

“…Seasonal variations in hematologic parameters resulting in erythrocytosis or leukopenia are well documented in RT and explained by physiological adaptation to external conditions [57,36] or to breeding cycles with gonad maturation [8]. Disturbance in hematologic parameters can also be induced by acute, sub-chronic or chronic exposure to GBHs, as reported in various fish species [41,31,29,74,56,40].…”