Studies on Vitamin B₁₂ of Aquatic Animals-IV

The Vitamin B₁₂ of the Starfish (1)

Abstract

Predatory activity of the yellow starfish, Asterias amurensis versicolor Sladen, has teen so rampant in clam culture grounds in the Tokyo Bay that commercial harvest of clams for the present season and in the future has been seriously threatened. In the course of investigating the situation, attention has been attracted to the vitamin B₁₂ contents of the asteriod which was expected to be as high as its food, shell-fish, in view of knowledge obtair. d p eviously¹⁾.
Of numbers of individuals collected from the invaded area in February and March, 1954 the samples which were apparently in a medium size presented the weight by anatomical parts as shown in Table 1. The vitamin B₁₂ contents have been determined by microbiological assay using Euglena as the test organism. As the result it has been revealed that the viscera, and especially the pyloric caecum, contain vitamin B₁₂ by far more than those of other marine animals, except ?? few cases, reporte1 in the preceding papers¹⁾ (Table 2).
Since vitamin B₁₂ can be easily extracted from the starfish by enzymic digestion, as has been demonstrated (Table 3), it is suggested that this echinoderm may be utilized as a potential source of vitamin B₁₂ for human consumption as well as for feeding of livestock, providing an adequate mcthcd for industrial prccessing is established. And such utilization, if avilable on industrial scales, will have an effect, at the same time, to alleviate depredation of the starfish upon commercially important shell-fish in the area.