Every blue ribbon eel is born as male. Juveniles and sub-adults are black with a yellow dorsal fin. When they reach adulthood, they keep the yellow fin but the body turns blue and starts developing female reproductive organs. ​When they reach their full size, they turn into female and change their color to complete yellow. They will then find a mate, lay their eggs, and die within a month. It is due to their short lifespan that the female ribbon eels are rarely observed.