The reconstitutional performances of the Leptomedusa Campanularia jonstoni

Abstract

The reconstitutional abilities of the Leptomedusa Campanularia jonstoni (Alder) were studied by means of isolating various regions and sectors of the animals. All such fragments first restore the typical bell-shape by a rapid morphodynamic process, the mechanisms of which are not yet understood. In a second, much slower step, the missing organs such as manubrium, radial and circular canals, tentaces, statocysts and gonads are regenerated to a varying extent. The original radial symmetry is practically never restored. The manubrium plays a key role in these processes. When it is present in the fragment isolated, the regeneration of the peripheral components of the vascular system (radial canals) originates from the manubrium. When the fragment is devoid of a manubrium, the latter is first reconstituted by the subumbrellar tissues including ectoderm and entoderm. Interradial sectors lacking radial and circular canals, as well as a manubrium, are capable of reconstituting a small medusa using exumbrellar and subumbrellar tissues alone. Gonads are regenerated along with the reconstitution of radial canals. The histodynamics of these processes have, so far, not been investigated.