Smith, T.I.J., Jenkins, W.E., Heyward, L.D., Sr.
Abstract:
In 1996, two trials examined the hatchery production of white bass,
Morone chrysops, and sunshine bass, white bass female x striped bass
(M. saxatilis) male using cultured broodstocks which were naturally
conditioned in outdoor tanks. Strip-spawning of hCG-treated 4 year
old female white bass (307.6 mm TL) and 3-4 year male striped bass
yielded 44,431 eggs/female and a hatch level of 63.9% (28,400 hybrid
fry/female). Strip-spawning of four year old white bass males and
females, mean 301.1 mm TL, and 407.7 g, using hCG resulted in a
mean egg production of 48,102 eggs/female with a hatch level of
63.3.0% (30,492 white bass fry/female). No statistical differences
(T-test, P > 0.05) were detected among fish size, egg and fry
production or hatching level. These hatch rates are comparable to
those obtained by public hatcheries throughout the southeast.
The second study compared tank-spawned HCG-treated white bass to
strip-spawned fish. Although production of fry (mean 16,733
fry/female) was substantially lower among tank-spawned fish, no
difference was detected (Mann -Whitney Rank Sum Test P > 0.05).
Results of these studies indicate that cultured striped bass male and
white bass female broodstock can be used by hatcheries to reduce
their current dependence on annual acquisition of wild broodstock.
(South Carolina Department of Natural Resources, Marine Resources
Research Institute, P. O. Box 12559, Charleston, South Carolina,
USA 29422)