Description:
Wurzelmundqualle. Beispiel ökologischer Anpassung durch Umfunktionieren einer ursprünglichen Bewegungsweise: Die durch Glockenkontraktion frei schwimmende Meduse setzt sich mit der Schirmoberseite fest; Glockenkontraktionen strudeln Nahrungspartikel in die lappenförmigen Mundarme
Cassiopeia xamachana, a scyphozoa, belongs to the family of rhizostomae. This medusa lives in still lagoon waters of tropical coasts. Whereas other species of rhizostomae spend their lives swimming free, Cassiopeia changes over to a stationary mode of life. It swims, like all medusae, by means of rhythmic contractions of its umbrella. It can, however, also fasten itself to a substrate, whereby the upper surface of the umbrella serves as suction pad. The contractions then continue at a slower pace, creating a water current which is filtered for food particles. The film shows aquarium shots of Cassiopeia xamachana swimming free and attached to a surface