Swimming Speed and Swimming Metabolism of Atlantic Cod ( Gadus morhua ) in Relation to Available Food: A Laboratory Study
A laboratory study was performed on how young Atlantic cod (Gadus morhua) regulate their swimming speed according to available food. A circular tank 15 m in diameter was divided into six sectors, each containing two cod ranging in length from 29 to 42 cm. Live fish 5 cm long on average were used as...
| Published in: | Canadian Journal of Fisheries and Aquatic Sciences |
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| Main Author: | |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
Canadian Science Publishing
1993
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| Subjects: | |
| Online Access: | http://dx.doi.org/10.1139/f93-277 http://www.nrcresearchpress.com/doi/pdf/10.1139/f93-277 |
| Summary: | A laboratory study was performed on how young Atlantic cod (Gadus morhua) regulate their swimming speed according to available food. A circular tank 15 m in diameter was divided into six sectors, each containing two cod ranging in length from 29 to 42 cm. Live fish 5 cm long on average were used as prey. For the first 48 d food intake was changed every 1 or 2 wk equally for all six groups. During the last 31 d each group received different amounts of food. The mean swimming speed was highest (0.6 bl/s) when food intake was about half the maximum intake and lowest (0.2 bl/s) when food was unlimited or not available. Swimming metabolism was related to food intake in a similar way, but with a larger difference between the most active (50 mg O 2 ∙kg −1 ∙h −1 ) and the least active group (10 mg O 2 ∙kg −1 ∙h −1 ). Maximum sustained swimming metabolism was estimated to be about 0.6 times the standard metabolism. The estimated energetic cost of swimming as a percentage of energy obtained from the food decreased with food intake from 24% at maintenance ration to 2% at maximum food intake. On a log–log plot swimming speed decreased linearly with time after encounter of prey. |
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