Ephyrae rhopalium numbers and observations of the up-side down jellyfish Cassiopea (Cnidaria: Scyphozoa)

Thesis (M.S.)--University of Hawaii at Manoa, 2007.Includes bibliographical references (leaves 32-36).vii, 36 leaves, bound 29 cmJellyfish rhopalia are gravity sensory organs located on the margin of the animal's bell. Rhopalia are therefore associated with jellyfish behaviors such as swimming, pulsing, and orientation. Often these rhopalium numbers are fixed in the medusa phase of its life cycle and vary among different species of jellyfish. Rhopalium development was documented in developing Cassiopea sp. jellyfish. These ephyrae were observed on a weekly basis until rhopalium numbers remained constant. It was observed that developing rhopalia can occur with natural structural precursors or de novo. Further results showed that there is high variation between clonal ephyrae in regards to the final rhopalium numbers. These observations support the research performed on clonal Aurelia ephyrae