The first recorded occurrences of the invasive crab Callinectes sapidus Rathbun, 1896 (Crustacea: Decapoda: Portunidae) in coastal lagoons of the Balearic Islands (Spain)

The introduction of species is a major threat to biodiversity conservation. Island biodiversity is especially sensitive to the arrival of new species, and species introductions are one of the major concerns of conservation management policies. Here, we report for the first time the arrival of Callinectes sapidus, a new potentially invasive crab species from the East coast of America to the Balearic Islands (Spain). It appeared simultaneously in both Mallorca and Menorca islands. Nine different records of 20 individuals were documented in six different localities, suggesting an initial colonization process of the territory.