Studies on Vitamin B₁₂ of Aquatic Animals-VI

The Vitamin B₁₂ Level in the Gastric and Intestinal Contents of Fish

Abstract

By measuring vitamin B₁₂ amounts of gastric and intestinal contents for various species of fish according to the bioassay using Euglena gracilis the following results were obtained:
1. In case of fishes listed in Table 2, vitamin B₁₂ level of intestinal contents is much higher than that of gastric contents, suggesting that bacteria synthesize vitamin B₁₂ in intestnal tract. The intestinal contents of such high B₁₂ values may be considered as an important B₁₂ source in manufacturing fish solubles from these fishes.
2. The intestinal contents of the fishes shown in Table 3 reveal no singificant increase in B₁₂ level as compared with the gastric contents. It is presumed that vitamin B₁₂ synthetic activities of the intestinal bacteria are only weak or absent in these fishes.