In order to sustain themselves they used their beautiful singing voices as a source of income. They lived in oceans all around the world. In some cultures, such as that of the Greeks, they were represented as half woman, half fish. In other cultures, such as that of the Vikings, they were entirely fish-human hybrids. No matter what form they took, however, they all shared similar traits: beautiful voices, extraordinary longevity, and no hope of salvation unless someone else saved them by killing them. In order to attract sailors to hear them sing, the mermaids would use their charms to seduce men. If the sailor was kind enough to invite them on board his ship, the mermaid would pretend to be a human being in distress and need his help. Once on board, she would distract the crew with her beauty and beg them not to tell her husband or father about the adventure. Then she would ask them for money so she could return home. The more money the sailor gave her, the longer his mermaid would stay away from her family.