Range extension of the southwestern Indian Ocean endemic Centropyge debelius (Teleostei: Pomacanthidae)

Previously only known from the western Mascarenes and Aldabra, Centropyge debelius (Pyle 1990) is recorded for the first time at Mayotte and Tromelin islands. These new records expand the geographical distribution of C. debelius in the south-western Indian Ocean, but also the depth range of the species, as the species was observed for the first time at depths shallower than 30 m. It emphasizes the crucial importance to improve the prospecting effort on little studied areas and the "twilight zone" of reef habitats, in order to access to a better understanding of biodiversity and ecological functionalities.