juvenile yellowtail damselfish

''Microspathodon chrysurus'' is a Damselfish from the Western Atlantic. It occasionally makes its way into the aquarium trade, where it is known as the Marine Jewelfish . It grows to a size of 21 cm in length. When juvenile it has brilliant blue spots on a dark blue back ground. It is probably the most aggressive of all Damselfish, and should be kept with fish substantially larger and more robust than itself.