Eel tattoo means happiness and love. Eels are so slippery that people often can't catch them. For most people, eel is a kind of delicious food. These two characteristics make people often associate eel with love.
Eels grow in rivers on land. When they mature, they migrate to the sea to lay eggs. They only lay eggs once in their life and die after laying eggs. This life pattern, contrary to anadromous migration of salmon, is called catadromous migration.