We report the occurrence in the inner fishing port of the Málaga harbour (southern Spain) of an established population of the gastropod Marginella glabella, native on West African Atlantic coasts of Morocco to Senegal and also present at the Canary Islands. This is the third gastropod species with a tropical Atlantic origin found as an established population in the Mediterranean. In spite of its presumably scarce self-dispersal ability due to its direct development, it should be considered an invasive species since it is potentially able to spread out from the area currently occupied and preys voraciously on autochthonous gastropods. It is suggested that this species was introduced during the 1990s as within port discarded by-catch of Málaga-based trawlers, which at that time were fishing on the Atlantic coast off Morocco and the Canary–Saharian bank.
