First occurrence of Actaeodes tomentosus (H. Milne Edwards, 1834) (Brachyura: Xanthidae: Actaeinae) in the Mediterranean Sea

The presence of the crab Actaeodes tomentosus, native to the Indo-Pacific Ocean and the Red Sea, is documented for the first time in the Mediterranean Sea, on the basis of two specimens collected from Rhodes Island (Aegean Sea), a marine area particularly vulnerable to warm-water alien invasions. Along with the recent report of Xanthias lamarckii in similar conditions and region, the finding of another non-indigenous xanthid poses many questions regarding their occurrence in the area. Apart from Lessepsian migration, other possible vectors of introduction are therefore examined.