Doroshov, S.
Absract:
Commercial culture of white sturgeon emerged in the 1980s, driven by the interest of aquaculturists in this highly valued endemic species and the development of hatchery technology at the University of California. Current annual production of white sturgeon in California and Idaho is about 700 MT, greater than the combined annual catch of the commercial and sport fisheries on the Columbia River. Similar production has been achieved by the white sturgeon industry established in northern Italy.
Development of broodstock and domestic breeding of white sturgeon in California has entirely replaced gamete and fingerling supplies from the wild-caught broodfish, previously a major hurdle in sturgeon culture. Males and females mature at mean ages of 4 and 8 years and have annual and biennial reproductive cycles, respectively. Ovulation and spermiation are induced by hormonal treatment. The longevity of female sexual maturation, large size of broodfish (body weight up to 100 kg in repeatedly spawned females) and the labor-intensive hatchery procedures require the accurate prediction of the ovulatory response and maximum reproductive efficiency. Spawning and hatching success rates of 70-90% are now being achieved by the sturgeon industry.
White sturgeon is raised intensively throughout the life cycle. Larvae readily accept artificial diets and generally exhibit high survival to metamorphosis. The fingerlings appear to be the most vulnerable life stage of sturgeon in culture because of their high susceptibility to stress and diseases. Grown juvenile and subadult sturgeon are hardy and well suited to a high-density, intensive production system. They are raised in flow-through tanks, raceways, earthen ponds, and water recirculation facilities on artificial diets with 36-42% protein and at biomass density of 40-60 kg m3. Major finished products include 7-10 kg fish for the restaurant market, smaller pan-sized fish for the live fish market, smoked sturgeon fillet, and caviar.
The white sturgeon industry succeeded in domestication of large anadromous sturgeon species and established renewable sturgeon resources for human use. However, many problems are yet to be resolved to establish an effficient culture system with higher rates of economic return. The ongoing collaborative studies of universities and commercial producers will enhance further development of sturgeon culture.
(Department of Animal Science, University of California-Davis, Davis, California 95616, USA)
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