ヒラメの白化とリボフラビン含量との相関について

Abstract

To elucidate the relationship between riboflavin content and body color (melanin content), albinic juvenile flounder Paralicthys olivaceus were examined for riboflavin in the skin and muscle. In the normal juvenile fluounder, the riboflavin content reached 1, 200μg/100g in the black skin of the ocular side. The values obtained from the albinic individuals were less than one tenth of that of the normal ones; the more the degree of albinism, the smaller the amount of riboflavin. There was little difference between the albinic and the normal individuals as for riboflavin content in the blind side. The riboflavin content in the muscle of the normal individuals was roughly proportional to that in the skin and was higher in the ocular side than in the blind side. In piebald individuals the riboflavin content of the skin was remarkably higher in the black part than in the white part. It was confirmed by paper chromatography that all of the riboflavin in the skin of both the norrnal and the albinic individuals existed as free type. From the above results, it seems that there is a close relationship between riboflavin con-tent and body color (melanin content). As riboflavin is a photosensitive substance, melanin formation should be accelerated by its photosensitive action under the sun light.