Swimming of rhizostomid medusa, Stomolophus nomurai
Stomolophus nomurai is one of the largest species in Scyphozoan. Diameter of its umbrella is about 1 meter. It is bred around the East China Sea and the southwestern coast of the Korean Peninsula, and is often cast away on the coast of the Japan Sea in autumn. The "medusa" is a matured individual of sexual generation of Cnidarian. The interior surface of its umbrella has ring and radial muscles, and its opening and closing movement makes it possible swim as shown in this movie. However the movement abilitiy is not so high, therefore it cannot swim against strong tidal current.
(Recorded on 10/Oct/2003 at Tamagawa, Echizen-cho, Fukui, Japan)
This movie is registered in Animal Behavior Movie Archives.
(Registrant: ISHIDA, So / Data ID: momo031013sn01b)
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