Impacts of
Increased Tempering Lengths on Twenty-Four-Hour Survival of Hybrid Striped
Bass Fry
H.D. Walker, G.I. Coates, S.Wilhelm-2000
North American Journal of Aquaculture, 32(4): 316-318
Abstract:
We evaluated the impacts of different tempering rates
on the 24-h survival of 4-d-old palmetto bass (female striped bass Morone
saxatilis × male white bass M. chrysops). We used the increase rate of pH
as a measure of water quality change. Four tempering rates were conducted
concurrently to determine the importance of extended tempering time on the
survival of fry following an adjustment to an increase in pH, alkalinity,
and hardness. Fry were tempered to increases of 0.6–1.9 pH units over
periods from 11 to 330 min, producing pH tempering rates of 11.4–0.02/h.
The study produced average tempering rates and average survival rates for a
set of controls and four treatment groups. Average fry survival rates ranged
from 75% in the control replicates with a pH tempering rate of +0.01/h to
48% for fry subjected to an increase of 1.9 pH units in 10 min or a
tempering rate of +11.4 pH/h.
(Rock Creek State Fish Hatchery, Nebraska Game and
Parks Commission, HC 69 Box 5, Parks, Nebraska 69041, USA)
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