Oval butterflyfish

The oval butterflyfish ("Chaetodon lunulatus"), is a species of marine ray-finned fish. It is found in the Pacific Ocean from Eastern Indonesia to the Hawaiian islands. 
Relation with other species.
This is one species of a closely related group which includes the Blacktail butterflyfish, which is found in the Red Sea and Gulf of Aden. It is also related to the Melon butterflyfish, which is found in the Indian Ocean.
Other names.
This fish is also known as the red-finned butterflyfish or redfin butterflyfish.