First record of Pomacentrus atriaxillaris (Teleostei: Pomacentridae) from Mayotte Island

Previously treated as endemic to northwestern Madagascar, Pomacentrus atriaxillaris is reported for the first time from the lagoon of Mayotte Island, at a depth of 22 m. This observation confirms there is a range extension for this species and enhances the hypothesis of larval connectivity between the Comoro Archipelago and northwestern Madagascar. This paper also highlights the importance of prospecting coral pinnacles on the soft bottoms of Mayotte's lagoon to better understand of the biodiversity and ecological functions of these understudied habitats.