Ribbon eel

The ribbon eel is a slender, dramatic moray eel (family Muraenidae) from the Indo-Pacific. It has a ribbon-thin body with expanded, flaring nostrils and undergoes a remarkable color change with age and sex: juveniles are black, males become electric blue with yellow, and older individuals turn largely yellow as females. It is a largely solitary, burrow-dwelling fish that spends most of the day with only its head protruding from a crevice or the sand. It is generally peaceful but is a demanding aquarium subject. A sand bed with rocky burrows and a very secure lid are essential. It is a carnivore that hunts small fish and crustaceans, but it is notoriously reluctant to feed in captivity, and many specimens refuse food and slowly starve. It is recommended only for expert keepers prepared to coax it onto live or fresh meaty foods.