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-- -..........,.-.--- 64 JOURNAL OF APPLIED AQUACULTURE deformed fish revealed spinal deformities, including displaced ver- tebral columns, compressed spinal cords, and displaced muscula- ture (E. MacConnell, Bozeman Fish Technology Center, pers. comm.). Such abnormalities in fishes are typical of vitamin C defi- ciencies (reviewed by Steffens 1989). Storage apparently affects the vitamin concentration of dry diets, and dry catfish diets lost 50% of the original concentration of ascorbic acid when stored at 210C for three months (Piper et al. 1982). For this and other reasons, open- formula feed specifications usually recommend a shelf-life of 90 days for most dry diets (U.S. Fish and Wildlife Service, Open For- mula Feed Specifications). All diets used in this study were kept refrigerated but Were stored for longer than 90 days. Consequently, it is possible that many of the deformities may have been caused by a loss of vitamin C during storage. Differences in the growth and survival presumably reflected pal- atability and nutritional needs, but more work is needed to further evaluate the efficacy of available diets for the fish or to develop new' diets' for them. In the interim, the BioKyowa diets appear to pro- duce satisfactory growth for razorback suckers during the first 126 days of life. Since all diets in Phase III produced some spinal and muscular deformities, care should be taken to provide sufficient vitamins, either by adding them or by storing diets for only short periods (<90 days). ACKNOWLEDGMENTS This study was supported, in part, with funds provided by the Bureau of Reclamation and U.S. Fish and Wildlife Service. We thank T. R. Hatch, M. H. Hughes, and D. L. Moses for their tech- nical assistance. C. A. Karp improved an earlier draft of the manu- script. The Bozeman Fish Technology Center, Bozeman, Montana conducted proximate analysis of diets and histological examination of study fish. REFERENCES Association of Official Analytical Chemists. 1984. Official Methods of Analysis, 14th cd., Association of Official Analytical Chemists. Arlington. Virginia. Hamman. R. L. 1987. Survival of razorback suckers cultured in earthen ponds. Progressive Fish-Culturisl 49:138-140.