The effects of
swimming exercise on growth and whole-body protein and fat contents of fed
and unfed fingerling yellowtail
H. Yogata, H. Oku-2000
Fisheries Science, 66(6): 1100-1105
(from Current Contents)
Abstract :
Fingerling yellowtail Seriola quinqueradiata (initial
mean body weight 4.3 g), an active pelagic fish, were reared under fed (4
weeks) and unfed (1 week) conditions to investigate the effects of swimming
exercise on growth performance and whole body composition. The fish were
raised in three water velocities: < 0.3 body length/s (bl/s), 1.0 bl/s,
and 2.25 bl/s and fed diets containing two fat levels (13.2 and 20.3%). The
exercised fish had significantly higher weight gains and feed efficiencies
than the unexercised fish in both dietary fat levels. A second-order
polynomial suggested that the optimum water velocity for the growth occurred
at about 1.6 bl/s. The whole-body crude protein and fat contents were higher
in the exercised fish than in the unexercised fish, and consequently
apparent body protein and fat retentions were improved in both dietary fat
levels by swimming. However, during 1 week starvation, body fat loss/g body
weight loss was higher in the exercised fish than in the unexercised fish.
The results of the present study clearly show that swimming condition
improves growth performance of fingerling yellowtail, and suggest that
swimming exercise stimulates both anabolism and catabolism of protein and
fat; however, under fed conditions anabolism appears superior to catabolism.
(Natl Res Inst
Aquaculture, Nansei, Mie 5160193, Japan, e-mail :
ogata1@ss.nria.affrc.go.jp)