Bioluminescence is a mode of communication between the luminous individual and its biotic environment. The aim of this research is to document the function of bioluminescence in a small cosmopolitan ophiuroid species. In situ observations and aquarium experiments with image intensification and light measurement techniques are used to study prey/predator interaction and intraspecific communication. Light emission in ophiuroids present characteristics varying from one species to the other. Little is known about control mechanisms; this research aims to make a comparative study of bioluminescence control in three ophiuroid species: Amphiura filiformis, Ophiopsila aranea and Ophiopsila californica. Several steps are considered: identification of the nervous control nature using agonists and antagonists of the most common neurotransmitters found in Echinoderms; characterization of ionic movements using patch-clamp techniques in the luminous cells (photocyte) membrane during light emission.