mediterranean eel

Beautiful adult male ribbon eel in open water looking for a new home!
Band eels are a very unusual marine species. They are born black with a yellow dorsal fin. Black turns blue when they become mature males. And finally, towards the end of their life, when they reach a size of about 1 meter in length, they turn completely yellow and turn into females. At this point, they will live long enough to lay eggs and then die. That is why they are called protandric - a type of life cycle.