Effects of continuous acute and intermittent exposure on the tolerance of juvenile yellow catfish (Pelteobagrus fulvidraco) in total dissolved gas supersaturated water

Chenyang Cao; Yuxuan Deng; Qingjie Yin; Na Li; Xiaoqing Liu; Haoran Shi; Yao Yang; Liangfang Xu

doi:10.1016/j.ecoenv.2020.110855

Effects of continuous acute and intermittent exposure on the tolerance of juvenile yellow catfish (Pelteobagrus fulvidraco) in total dissolved gas supersaturated water

Ecotoxicol Environ Saf. 2020 Sep 15:201:110855. doi: 10.1016/j.ecoenv.2020.110855. Epub 2020 Jun 13.

Authors

Chenyang Cao¹, Yuxuan Deng², Qingjie Yin³, Na Li², Xiaoqing Liu⁴, Haoran Shi², Yao Yang², Liangfang Xu²

Affiliations

¹ Key Laboratory of Fluid and Power Machinery, Ministry of Education, Xihua University, Chengdu, 610039, China; School of Energy and Power Engineering, Xihua University, Chengdu, 610039, China.
² Key Laboratory of Fluid and Power Machinery, Ministry of Education, Xihua University, Chengdu, 610039, China.
³ Sichuan Water Conservancy Vocational College, Chengdu, 611130, China.
⁴ Key Laboratory of Fluid and Power Machinery, Ministry of Education, Xihua University, Chengdu, 610039, China; School of Energy and Power Engineering, Xihua University, Chengdu, 610039, China. Electronic address: liuxq@mail.xhu.edu.cn.

PMID: 32540620
DOI: 10.1016/j.ecoenv.2020.110855

Abstract

Total dissolved gas (TDG) supersaturation generated by discharged flood water may cause the death of fish downstream of dams and severely threaten their survival during the flood season. No study has performed to investigate the effects of TDG on fish dwelling in shallows in China. Furthermore, varied TDG levels are caused by the varied flow of flood water during the spill season. Fish may alternatingly experience intermittent TDG exposure from equilibrated water and TDG-supersaturated water. However, little research on the effects of intermittent TDG exposure on fish has been conducted. To evaluate the tolerance of fish to continuous acute TDG exposure, juvenile yellow catfish living in the shallows were exposed to TDG-supersaturated water at 125%, 130%, 135% and 140% TDG for 96 h. The results showed that the juvenile yellow catfish exhibited obvious gas bubble disease (GBD) and abnormal behaviours (e.g., exophthalmos and bubbles on fins). The survival probability declined with the arising TDG levels. The median survival time (ST₅₀) of yellow catfish was 8.57, 18.1, 33.86 and 58.84 h at above TDG levels, respectively. To further investigate the effects of intermittent TDG exposure on juvenile yellow catfish, the fish were subjected to varied TDG levels (125%, 130%, 135% and 140%) for a specific duration (3 h and 6 h) and then underwent a period of recovery (3, 6 and 9 h) in equilibrated water. The results showed that an increase in recovery time (or decreasing exposure time) can prolong the survival time of yellow catfish and improve their survival probability at the same exposure time (or same recovery time). Compared with that under continuous acute exposure, the ST₅₀ of juvenile yellow catfish increased significantly with intermittent exposure. Intermittent exposure can enhance the tolerance of juvenile yellow catfish to TDG. The application of the results may contribute to the protection of aquatic organisms and the formulation of the scheme of reservoir operation in the Yangtze River.

Keywords: Intermittent exposure experiments; Median survival time (ST(50)); Survival probability; TDG-Supersaturated water; Yellow catfish.

MeSH terms

Adaptation, Physiological / drug effects*
Animals
Behavior, Animal / drug effects
Catfishes / physiology*
China
Gases / analysis
Gases / toxicity*
Probability
Rivers / chemistry*
Survival Analysis
Water Movements
Water Pollutants / analysis
Water Pollutants / toxicity*
Water Quality

Substances

Gases
Water Pollutants