First documented record of the Atlantic blue crab Callinectes sapidus Rathbun, 1896 from the southwestern Mediterranean coasts

A previous record of the alien crab Callinectes sapidus from the Algerian coasts was based on a photograph provided by a fisherman showing the dorsal side of a single individual. In this contribution, we confirm this presence in the mouth of the Mafragh Estuary in eastern Algeria, where four individuals of this species were found on 19 November 2019. The specimens examined are one female (60 mm CL, 125.9 g) and three males (60-66 mm CL, 120.4-176.8 g). This discovery confirms the presence of this species in the southwestern Mediterranean Basin where it could become invasive in suitable habitats.