The gobiid teleost Zebrus zebrus (Risso, 1826), formerly believed to be restricted to the Mediterranean Sea, has been found for the first time in the Atlantic, on the SW coast of Spain. More than a thousand specimens sampled over almost four years have revealed the preference of Zebrus zebrus for the intertidal pools. The number of specimens in each pool was in direct relation with the volume of the pool. This species has been abundant through all the year in some localities.