Is there a link between morphological, physiological and genetic variability of the ophiuroid Amphipholis squamata?

Amphipholis squamata is a small ophiuroid considered to be distributed worl dwide except in Polar Regions. Numerous colour varieties were reported fur this species, which is also bioluminescent. It is hermaphrodite and brood p rotecting; both selfing and outcrossing occur. A high genetic variability w as observed among adult individuals belonging to very close (Mediterranean) local populations. Three distant populations were investigated in order to characterize morphological, physiological and genetic variability. In the population of Normandy (France), Amphipholis were collected under stones of tide pools; ophiuroids from Sicily (Italy) were collected in a Cymodocea n odosa meadow from a lagoon completely isolated from the sea. since 10 years ; individuals from Santa Barbara (USA) were sampled in the aquarium system of the Marine Institute. Four colour varieties are studied throughout the s ampled populations and each exhibits its own capability to produce light: ( 1) a spotted variety is present in the 3 populations and produces light of high intensity; (2) the orange, grey and black varieties are only present i n the population of Normandy and produce light of lower intensity. Genetic variations were revealed by RAPDs. Preliminary results indicate that generi c structure is homogenous for each colour variety within a population while , as expected, it shows inter-population variations for the same variety. T his suggests that polychromatism and bioluminescence might be good indicato rs of variability of genotypes only at an intra-population level.