Effects of Partial Tank Covers on the Growth of Juvenile Feral Rainbow Trout during Hatchery Rearing
M.E. Barnes, D.J. Durben-2003
North American Journal of Aquaculture, 65(4):
344–348
Abstract:
Partial tank covers were evaluated for their effects
on the growth of juvenile feral McConaughy strain rainbow trout Oncorhynchus
mykiss during hatchery rearing. Trout were reared in 1999 and 2000
in circular tanks that were either completely open on top or partially (29%)
covered. Trout reared in tanks with partial covers were 93 mm long at the
end of 55 d of rearing in 1999, which was significantly longer than the
88-mm mean length of trout reared in uncovered tanks. Total lengths were
also significantly different after 34 d of rearing in 2000: 81 mm for fish
from partially covered tanks and 78 mm for fish from open tanks. The total
weight gains of fish per tank were significantly greater (23.9 versus 22.7
kg) and feed conversions were significantly better (0.83 versus 0.87) in
partially covered tanks in 1999. In 2000, the total weight gain of fish per
tank was 15.4 kg in tanks with partial covers and 13.5 kg in uncovered
tanks, and the respective feed conversions were 0.90 and 1.05. However,
neither weight gain nor conversion was significantly different in 2000. No
significant differences in percent mortality were observed in fish reared
with or without partial covers.
(South Dakota Department of Game, Fish, and Parks, McNenny State Fish
Hatchery, 19619 Trout Loop, Spearfish, South Dakota 57783, USA)