An acute increase in water temperature can decrease the swimming performance and energy utilization efficiency in rainbow trout (Oncorhynchus mykiss)

• Published in: Fish physiology and biochemistry 2021-02, Vol.47 (1), p.109-120
• Main Authors: Yin, Leiming, Chen, Lei, Wang, Maolin, Li, Hongquan, Yu, Xiaoming
• Format: Article
• Language: English
• Subjects: Animal Anatomy; Animal Biochemistry; Animal Physiology; Animals; Biomedical and Life Sciences; Body mass; Body temperature; Energy Metabolism; Energy utilization; Fish; Freshwater & Marine Ecology; Freshwater fishes; Histology; Life Sciences; Mass; Metabolic rate; Morphology; Oncorhynchus mykiss; Oncorhynchus mykiss - physiology; Oxygen Consumption; Salmon; Statistical analysis; Swimming; Swimming - physiology; Temperature; Trout; Water; Water temperature; Zoology
• ISSN: 0920-1742; 1573-5168
• DOI: 10.1007/s10695-020-00897-3

In order to evaluate the effects of acute temperature exposure on the swimming performance of rainbow trout ( Oncorhynchus mykiss ), the critical swimming speed ( U crit ) and oxygen consumption rates (MO 2 ) were determined at different temperatures (13.2, 18.4, and 22.5 °C). The U crit and MO 2 of different body mass (109.44, 175.74, and 249.42 g) fish were also obtained at 13.4 °C. The U crit first increased as the temperature increased from 13.2 to 15.2 °C, which was calculated to be the optimal temperature for the U crit , and then decreased with increasing temperature. The optimal swimming speed ( U opt ) showed a similar trend to the U crit . At a given swimming speed, the MO 2 and cost of transport (COT) were significantly higher at 22.5 than at 13.2 °C, suggesting the energy utilization efficiency decreased with increasing temperature. The absolute values of U crit and U opt increased as the body mass increased from 109.44 to 249.42 g, whereas the relative values decreased. Although not statistically significant, the maximum metabolic rate (MMR) tended to increase with temperature but decrease with body mass. Results can be of value in understanding the behavioral and physiological response of rainbow trout to acute temperature change.