Vitamin C is known to perform numerous biochemical and physiological functions in both plant and animal metabolism (Tolbert, 1979). Most animals can synthesize this vitamin in the form of ascorbic acid in amounts sufficient to prevent the clinical symptoms of deficiency collectively known as scurvy. However, primates, guinea pigs, fish, shrimp, and some insects, bats, and birds require a dietary source of vitamin C to prevent or reverse scorbutic symptoms. Among these species, dietary essentiality of vitamin C in fish and shrimp probably results from an absence or insufficiency of L- gulonolactone oxidase (Wilson, 1973; Yamomoto et al., 1978). This enzyme is required for biosynthesis of ascorbic acid from glucose or other simple precursors (Lehninger, 1971).