Seis nuevos gasterópodos marinos alóctonos en el delta del Ebro (Cataluña, España)

The presence of six Atlantic gastropod species is reported near the aquaculture facilities of Delta del Ebro (Tarragona), in the Mediterranean Sea. Only Littorina littorea was present at huge numbers. The presence of these species seems related with the recent importation of mussels and oysters seed (juveniles) from similar facilities in the Atlantic coast of Spain