ISSN:
1095-8649
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Biology
Notes:
Oxygen consumption rates of adult spring chinook salmon Oncorhynchus tshawytscha increased with swim speed and, depending on temperature and fish mass, ranged from 609 mg O2 h−1 at 30 cm s−1 (c. 0·5 BL s−1) to 3347 mg O2 h−1 at 170 cm s−1 (c. 2·3 BL s−1). Corrected for fish mass, these values ranged from 122 to 670 mg O2 kg−1 h−1, and were similar to other Oncorhynchus species. At all temperatures (8, 12·5 and 17° C), maximum oxygen consumption values levelled off and slightly declined with increasing swim speed 〉170 cm s−1, and a third-order polynomial regression model fitted the data best. The upper critical swim speed (Ucrit) of fish tested at two laboratories averaged 155 cm s−1 (2·1 BL s−1), but Ucrit of fish tested at the Pacific Northwest National Laboratory were significantly higher (mean 165 cm s−1) than those from fish tested at the Columbia River Research Laboratory (mean 140 cm s−1). Swim trials using fish that had electromyogram (EMG) transmitters implanted in them suggested that at a swim speed of c. 135 cm s−1, red muscle EMG pulse rates slowed and white muscle EMG pulse rates increased. Although there was significant variation between individual fish, this swim speed was c. 80% of the Ucrit for the fish used in the EMG trials (mean Ucrit 168·2 cm s−1). Bioenergetic modelling of the upstream migration of adult chinook salmon should consider incorporating an anaerobic fraction of the energy budget when swim speeds are ≥80% of the Ucrit.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1046/j.1095-8649.2003.00217.x
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