Among the most represented sea creatures in the surrealist painting, the mermaids stand out, they are beautiful women which the animal part has taken the upper hand over. Their history goes up to Greek literature and through all the ancient, medieval and modern civilizations, reaching the contemporaneity in their intact mysterious sphere. They are animals that always had to deal with men, fascinating them and conducting people to the sin, revealing emphasized female qualities, even superior to real women’s ones. Temptresses in lands and seas, they seem to be finally trapped into the painting, that represents a magic fishing scene. Tails and hairs, emblems of beauty, are immobilized. The most significant pictorial effect is the movement: the tossing of the mermaids in the attempt of freeing their body from the net allows them to show solidarity each other, and it makes them heroes defending nature from the ruin the human being provokes, as final message of the painting.