Intraspecific Variations of Bioluminescence in a Polychromatic Population OfAmphipholis Squamata(Echinodermata: Ophiuroidea)

Six colour varieties were recognized in an intertidal population ofAmphipholis squamatafrom Normandy (France). Each variety exhibits its own capacity to produce light, the light emitted by the most luminous variety being 500 times more intense than that emitted by the least luminous one. Differences in luminescent capabilities observed between varieties do not seem to be due to differences in pigmentation or to be of exogenous origin. It was shown that the capability to produce light changes according to whether individuals are brooding or not, brooding individuals emitting a more intense light than non-brooding ones. This supports the defensive use of luminescence generally associated to ophiuroid production of light. However, light capabilities differ so much betweenA. squamatacolour varieties that bioluminescence could also be associated with another role in the species.