BODY THERMAL RESPONSE TO ENVIRONMENT TEMPERATURE IN RAINBOW TROUT (Oncorhynchus mykiss) DURING THE SUMMER SEASON.

The body temperatures of rainbow trout, Oncorhynchus mykiss were monitored from June through August 2018 in three trout farms from Bistrița-Năsăud County (Romania). The body temperature was measured from 3 different regions of the body: head, trunk (epaxial and hypaxial muscle region) and caudal peduncle. Body temperatures were compared to the basins water temperature. The lowest water temperature in the basins was recorded in May and June, in Șoimul de Jos farm, and the highest temperature in Fiad farm. In July, Strâmba farm, recorded the highest water temperature, and in August, Fiad farm. In all farms studied, the body temperature of the trout was higher than that of the basins water temperature regardless of the studied region. The highest differences between the basins water and body temperature in farms were found in the caudal peduncle and epaxial muscle regions, due to their role in locomotor mechanism. This is due to the high growth density, the feeding and the intensification of metabolism, with energy release, as well as a much higher level of stress than that encountered in the natural environment. [ABSTRACT FROM AUTHOR]