New records of two alien opisthobranch molluscs from the north-eastern Atlantic: Polycera hedgpethi and Godiva quadricolor

Polycera hedgpethi and Godiva quadricolor are two species of nudibranchs widely spread along the Indo-Pacific by shipping. The first of these two species was originally described from Californian coasts, while the second was described from temperate South African coasts. Records of both species outside the Indo-Pacific are scarce, but have already been recorded in the Mediterranean (Gulf of Naples and Adriatic, Italy; French coasts). Moreover, G. quadricolor in the Mediterranean has been misidentified and its significance misinterpreted. In this paper, we provide new records of a significant number of specimens of both species from the region of Agadir (Morocco, Atlantic), as well as that of an additional specimen of G. quadricolor from the Bay of Algeciras (Strait of Gibraltar). This last species is recorded for the first time for the Moroccan and Spanish fauna and P. hedgpethi is also new for the Moroccan fauna. The shipping activities carried out in the areas where the specimens reported in this paper have been collected, as well as their habitual eutrophic conditions, lead us to the expectation of the settlement in the near future, if not yet, of well-established populations of both species.