title: Does air-breathing meet metabolic demands of the juvenile snakehead,Channa argus, in multiple conditions.
abstract: The objective of this study was to examine how the respiratory metabolism of the snakeheadChanna arguschanged when it shifted from breathing water to breathing air, and how increased metabolic demands caused by temperature, feeding, and exhaustive exercise affect its survival in air. The results demonstrated that the oxygen consumption rate (MO2) of the snakehead was lower for aerial respiration than aquatic respiration by 12.1, 24.5 and 20.4% at 20, 25, and 30°C, respectively. Survival time was significantly shortened with increasing temperature and was negatively correlated with the resting MO2in air (MO2Air). No obvious feeding metabolic response was observed in the snakeheads fed at 1% and 3% body mass levels while breathing air. The maximum MO2Airof the snakehead after exhaustive exercise was significantly higher than the resting MO2Airof the control group. The results suggest that the snakehead could survive out of water by breathing air for varying lengths of time, depending on ambient temperature and metabolic demand. Additionally, some degree of metabolic depression occurs in the snakehead when breathing air. The metabolic demand associated with exercise in the snakehead, but not that associated with feeding, can be supported by its capacity for breathing air to some extent.
authors.affiliation: Key Laboratory of Freshwater Fish Reproduction and Development, Ministry of Education, School of Life Sciences, Southwest University, Chongqing 400715, China.
authors.forename: Yongli
authors.initials: Y
authors.lastname: Li
authors.affiliation: Key Laboratory of Freshwater Fish Reproduction and Development, Ministry of Education, School of Life Sciences, Southwest University, Chongqing 400715, China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Lv
authors.affiliation: Department of Clinical Medicine, Chongqing Medical and Pharmaceutical College, Chongqing 401331, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Zhou
authors.affiliation: Key Laboratory of Freshwater Fish Reproduction and Development, Ministry of Education, School of Life Sciences, Southwest University, Chongqing 400715, China.
authors.forename: Chenchen
authors.initials: C
authors.lastname: Shi
authors.affiliation: Key Laboratory of Freshwater Fish Reproduction and Development, Ministry of Education, School of Life Sciences, Southwest University, Chongqing 400715, China.
authors.forename: Ting
authors.initials: T
authors.lastname: Duan
authors.affiliation: Key Laboratory of Freshwater Fish Reproduction and Development, Ministry of Education, School of Life Sciences, Southwest University, Chongqing 400715, China luoguo@swu.edu.cn.
authors.forename: Yiping
authors.identifier: http://orcid.org/0000-0003-3312-6403
authors.initials: Y
authors.lastname: Luo
keywords: Air-breathing; Fish; Metabolic demand; Oxygen consumption