Tank Performance of Larval Saugeyes (Walleye × Sauger) Produced Out-of-Season and during Regular Season Spawning
M.A. Garcia-Abiado, S. Czesny, K. Dabrowski-2004
North American Journal of Aquaculture: 66(1): 48–52
Abstract:
In the north-central region of the United States,
hybrid saugeyes (female walleye Sander
vitreus [formerly Stizostedion
vitreum] × male sauger S.
canadense) have been recognized as an important species for
recreational fisheries and as a potential aquaculture commodity. We compared
the performance of larval saugeyes that were produced out of season with
larvae produced during the regular spawning season using intensive rearing
systems. Fertilized out-of-season and regular season saugeye eggs that were
produced by crossing two Spirit Lake, Iowa, female walleyes and two
Mississippi River male saugers were obtained from the Rathbun Hatchery, Iowa
Department of Natural Resources, Moravia. Out-of-season spawning was induced
by light and photoperiod manipulation. Eyed eggs were air-shipped overnight
at 10°C. First-feeding larvae (19,000 fish/tank) were stocked in six 800-L
cylindrical tanks provided with turbid water to prevent cannibalism and with
surface sprays to secure swim bladder inflation. The fish were fed
exclusively with commercial diets (Fry Feed Kyowa B-400 and B-700 and
Bio-Oregon starter diet). The specific growth rate (SGR), condition factor,
and survival were compared between saugeyes reared out of season (50 d) and
during the regular season (39 d). The mean SGR and survival of saugeyes from
the out-of-season experiment were significantly lower than those of saugeyes
from the regular season experiment (P < 0.05), although the
condition factor of the fish did not differ between the experiments.
Significant differences in SGR were also observed between tank replicates,
suggesting possible differences in the feeding responses of saugeyes within
a tank system. Large discrepancies (40–43%) were observed between actual
survival at the end of the rearing period and predicted survival based on
counts of dead larvae siphoned from the tank bottom, suggesting the
occurrence of cannibalism and the deterioration of larvae bodies prior to
tank cleaning. The actual survival (12–19%) of larval saugeyes in both
experiments shows some promise in the intensive rearing of saugeyes
exclusively on dry feeds
(School of Natural Resources, Ohio State University,
2021 Coffey Road, Columbus, Ohio 43210, USA)