Juvenile yellowtail kingfish were either forced to perform sustained swimming exercise at an optimal speed of 2.46 body-lengths per second (‘swimmers’) or allowed to perform spontaneous activity at low water flow (‘resters’) in a 3,600 L oval-shaped flume with flow created by an impeller driven by an electric motor. At the start of the experiment, ten fish were sampled as controls (346±6mm, 504±27g). After 18 days, swimmers (n=23; 385±4mm, 735±23g) showed a 92% greater increase in body-length and 46% greater increase in body-weight as compared to resters (n=23; 367±5mm, 661±32g). As both groups were fed equal portions, the feed conversion ratio (FCR) for swimmers was 1.21 and lower than 1.74 for resters. Using Doppler ultrasound imaging, we found a 31% higher blood flow in the ventral aorta of swimmers vs. resters (respect. 44±3 ml/min vs. 34±3 ml/min, under anaesthesia). This study shows that growth performance can be rapidly improved by optimal swimming, even without larger feed investments.
|Title of host publication||Book of abstractsof the International Congress on th Biology of Fish|
|Publication status||Published - 2014|
|Event||11th International Congress on the Biology of Fish, Edinburgh, UK - |
Duration: 3 Aug 2014 → 7 Aug 2014
|Conference||11th International Congress on the Biology of Fish, Edinburgh, UK|
|Period||3/08/14 → 7/08/14|