First record of the filament goby Discordipinna filamentosa (Teleostei: Gobiidae) from Mayotte Island, western Indian Ocean

The goby Discordipinna filamentosa, which was previously known only from the Northwest Pacific (Japan and Malaysia), is reported for the first time from the island of Mayotte, in the Southwest Indian Ocean. This new record represents an extension of the species' range of approximately 7000 km southwest of Malaysia. The observation of this species in deep reef habitats off Mayotte Island during an environmental survey highlights the need to intensify prospecting efforts in underexplored areas, particularly the twilight zones of deep reef habitats. Such efforts can result in a deeper understanding of the biodiversity and the ecological functions of such environments.