Fish and UV Radiation

A new study reveals that fish can determine other species solely based on the UV patterns on their faces. Scientists have known for a long time that some species of animals can see in UV but it is now being understood that two species of damselfish have keener UV vision. It is also being suggested that they use this as a way to communicate. Damselfish seem to be able to break some "rules" of UV vision. Normally UV scatters easily in air and water and most animals don't have many UV cones or photoreceptors. Scientists discovered this by putting two two intruders in the same tank, the damselfish only attacked one, but when UV vision was removed the preference disappeared.