An effective method to mass culture a lobate ctenophore (Bolinopsis mikado)

Abstract

This paper reports an effective and easy method to culture the ctenophore Bolinopsis mikado. Fifteen adult B. mikado individuals were maintained in a kreisel tank, and fertilized eggs, which were detected in the following days, were all raised together in the same tank. From the early development stage to day 13, the B. mikado cydippid larvae were only fed Artemia nauplii. The cydippid larvae were able to easily catch the Artemia nauplii excreted by adult B. mikado; therefore, they were considered capable of growing on excrement. Adult B. mikado individuals were removed from the tank when the cydippid larvae reached approximately 5 mm in length (day 14). The cydippid larvae were then transferred to a circular tank with a water spray chamber. Approximately 21 days after the early development stage, cydippid larvae had grown to lengths of approximately 20 mm and were then bred in the same manner up to the 5th generation. The greatest advantages of this culture method are that it is less cumbersome and only requires feeding and observation until the cydippid larvae attain a size that enables them to pursue live Artemia nauplii. Thus, damage to the living body due to water exchange and the labor involved are reduced, thereby allowing stable breeding of B. mikado.