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FSN Research Center, University of Rhode Island, West Kingston, RI 02892;
* School of Agriculture, Fisheries, and Human Sciences, University of Arkansas at Pine Bluff, Pine Bluff, AR 71601;
College of Veterinary Medicine, University of Georgia, Athens, GA 30602;
** School of Natural Resources, The Ohio State University, Columbus, OH 43210; and
School of Applied Marine Science, Cheju National University, Jeju, Korea
2To whom correspondence should be addressed. E-mail: rlochmann{at}uaex.edu.
Golden shiners (Notemigonus crysoleucas) require a dietary source of ascorbic acid (AA) for growth or survival, depending on diet composition. However, no quantitative requirements of golden shiners for AA for growth, health or survival have been determined, and specific deficiency signs have not been observed. The purpose of this study was to determine the effects of different dietary levels of AA on the growth and health of golden shiners fed diets containing 0218.5 mg AA/kg diet for 1016 wk. Weight gain, survival and gross deformities were assessed at 10 wk. The remaining fish were fed the same diets from wk 1116; hematology and alternative complement activity were then assessed and a subset of live fish from each tank was exposed to elevated temperature. Gross deformities appeared in fish fed 0 mg AA/kg diet at 9 wk. The 19.5 mg AA/kg diet was sufficient to prevent the deformities and optimize survival, whereas growth did not differ among treatments. Fish fed 40.3 mg of AA/kg diet had a higher survival rate than fish fed 0 or 19.5 mg AA/kg diet after exposure to elevated temperatures (3435.5°C). Alternative complement activity and visceral AA concentrations were greater in fish fed diets with 218.5 mg AA/kg than in all other groups. The results indicate that the dietary requirement of AA for golden shiners increases in response to heat stress, and that the alternative complement activity (one index of immune competence) was strongly enhanced in fish fed a diet with
10 times the amount of AA required to prevent deficiency signs.
KEY WORDS: ascorbic acid vitamin deficiency golden shiner alternative complement heat stress