Abstract
The present study investigated the interrelationships between feeding, food depriva- tion and swimming performance in juvenile grass carp Ctenopharynodon idellus. Oxygen con- sumption, as a function of swimming speed, was determined by fitting data to a power function. Speed exponents from oxygen consumption functions were 1.46, 1.23 and 1.91 with time after feeding of 6 h, 2 d and 2 wk, respectively, which indicated that swimming efficiency increased after digestion was complete and decreased with extended food deprivation. Excess post-exercise oxygen consumption (EPOC) increased slightly with time after feeding, and recovery time varied between 1 and 1.5 h after fatigue. The contribution of anaerobic metabolism began at swimming speeds 28.3 to 40.2% of critical swimming speed (Ucrit) and increased with time after feeding. Both optimal swimming speed and critical swimming speed decreased with time after feeding. The metabolic scope of grass carp decreased for at least 6 h after feeding (384 mg O2 kg -1 h -1 ). It nearly doubled after 2 d (727 mg O2 kg -1 h -1 ) and then declined after 2 wk throughout the duration of food deprivation (420 mg O2 kg -1 h -1 ). In conclusion, feeding and food deprivation affected swim- ming efficiency, metabolism (both aerobic and anaerobic) and swimming capability, with only slight effects on EPOC and recovery time. The results of the present study provide information which will assist in the design of fish ladders and resting pools and thus support fish migration and conservation of biodiversity.
Highlights
Hydraulic engineering is thriving in China, and many dams are under construction
Normal respirometer operating assumptions were made: (1) Swimming speed (U ) of the fish equals water flow speed, as measured with an acoustic Doppler velocity meter (Nortek) and (2) fish oxygen consumption is calculated based on the change in dissolved oxygen (DO, mg l−1), measured by a probe (Hach HQ30d)
Before the swimming tests, there was no change in condition factor (CF) in both Group 1 and Group 2
Summary
Hydraulic engineering is thriving in China, and many dams are under construction. The Ministry of Water Resources (2011) reported that 87 873 dams were operating in China at the end of 2010. Dams effectively control flooding and bring large economic benefits; they produce environmental impacts such as interrupting fish migration. The construction of fish ladders is an engineering approach for mitigating impacts on fish migration. An effective design requires knowledge of fish biology (Yagci 2010), swimming performance, which includes swimming behavior and capability as well as the metabolic changes associated with swimming (Ohlberger et al 2007, Tu et al 2011). Grass carp Ctenopharynodon idellus Valenciennes, 1844 is a large cyprinid species found primarily in
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
