The content of ascorbic acid and tocopherol in the tissues and eggs of wild Macrobrachium rosenbergii during maturation

Variations in the concentrations of ascorbic acid (AA) and tocopherols in association with the gonadal development of the freshwater prawn Macrobrachium rosenbergii were investigated in females captured in the Mae Klong River, Thailand. Mean ovarian AA levels ranged from 210 to 540 µg/g dry weight (dw) and were at least 11-fold higher than midgut gland (MG) levels. Variations in ovarian AA levels are believed to be related to the biosynthesis of steroid hormones, the formation of collagen, and the deposition of egg yolk compounds. alpha-Tocopherol (alpha-T) was the predominant form of vitamin E in prawn tissues and eggs. The level of alpha-T in the MG was constant, whereas in the ovaries, it ranged from 143 to 425 µg/g dw. The incorporation of a-T into the ovary was highly correlated (r² = 0.87) to ovarian lipid levels, which probably reflects the role of this vitamin as a major antioxidant agent. The present results provide further evidence of the essentiality of these vitamins in crustacean reproduction.