Triangular butterflyfish, Chaetodon baronessa

Chaetodon baronessa, commonly known as the Eastern triangular butterflyfish, is a small butterflyfish. Their body is yellow, but they're covered in blue spots so closely arranged that they form backwards facing V lines and make this fish appear purple from a distance. Their head has reddish-brown vertical stripes and the mouth is also brown to red coloured. The entire dorsal, caudal and anal fin have a beautiful yellow rim with also some black, blue and or red in it. They look very similar to C. triangulum. The difference is that C. baronessa a little more square is, compared to the triangle shape of C. triangulum, and the base colour from C. baronessa is more yellow compared to the grey-white in C. triangulum.

These fish are usually not aggressive towards other fish, but can become quite territorial sometimes. They live most of their life in pairs on coral reefs rich in Acropora. In an aquarium they can best be kept alone, unless a proven pair can be found. They're obligate corallivores and only feeding on Acropora polyps! This makes them not suitable for a fish-only tank and they will do best in a large reef tank stocked with fast growing Acropora.