The fish with a beautiful blue outline on its body and gills is the semicircle angelfish. This fluorescent colored line shines bright underwater, making them easy to spot.

They live in rocky areas and coral reefs of Indian Ocean and Mid Pacific Ocean south of Chiba. It can grow up to be 50 cm in length.

The pattern on their body changes drastically when they are fully-grown. They are beautiful and sturdy, making them a popular aquarium fish.