With its disc-shaped body, vivid blue colour, intense stare and pursed lips, the blue doctorfish looks like something from a child's drawing. On the seventh coin in the Luminous Marine Life series, it can also change colour with the help of ultraviolet light.
The blue doctorfish gets its name from bony projections on its tail that have a razor-sharp edge not unlike a surgeon’s scalpel. When a rival comes close, the striking yellow ‘scapel’ is extended as a threat to ward off attack, which can lead to nasty cuts being inflicted on the enemy should it fail to heed the warning.
Once young blue doctorfish grow roughly to the size of a 1 euro coin, they begin their life on the seabed. When illuminated with a special light at this stage, they glow an intense greenish colour. The fish play an important role in maintaining the health of coral reefs as they remove algae when feeding, which provides space for coral to flourish. In addition, their droppings fertilise the reef.
