Based on observed colour changes, it is generally considered a protandric hermaphrodite (first male, then changing sex to female), although this has yet to be confirmed. Colour change related to sex change is not known from any other moray eel species.

The presumed juveniles and subadults are jet black with a yellow dorsal fin, in adult males the black is replaced by blue, and adult females are entirely yellow or yellow with some blue to the posterior.