First record of the blue crab Portunus segnis (Crustacea, Decapoda, Portunidae), a non-indigenous species along the eastern Algerian coast

This paper reports the first record of the alien species Portunus segnis (Forskål 1775), in Jijelian coastal waters (East Algeria), with few observa-tions on its biology. We first observed debris of this Lessepsian species along the coast at Aouka in 2021. The following observations were reported in 2022, in two different sites, Aouka again and Bazoul, distant of 12km. This is the first report of this species along the Algerian coast. It has been considered as invasive in other Mediterranean areas such as Tunisia, where it has important socio-economic impacts, particularly on fisheries. As it expands westward along the African coast, this species will need to be closely monitored, as it will likely become invasive in suitable habitats of the Algerian coast.