Swimming, feeding, circulation and vision in the Australian box jellyfish, Chironex fleckeri (Cnidaria:Cubozoa)

Abstract

Juvenile Chironex fleckeri medusae were maintained in aquaria for several months. One individual was raised over a nine-month period to subadult condition for the first time. The medusae did not feed naturally in most aquaria but they accepted and digested prey items placed by hand onto the manubrium. Medusae maintained in planktonkreisels, however, extended tentacles and captured and ingested live Acetes, large prawns and fish by subumbrellar flexing of the pedalia. Digestion of prey was rapid and food particles were circulated directionally through functional canals and lacunae primarily by contractions of the bell but also by peristaltic contractions of interradial gastrovascular tissues. In the laboratory, medusae visually reacted to dark objects by swimming away from them. Swimming behaviour of medusae in the sea and natural predation by green turtles (Chelonia rnydas) on C. fleckeri are described.