Acanthurus olivaceus

Acanthurus olivaceus, commonly known as the Orangespot sugeonfish, is a large surgeonfish which needs plenty of swimming space. When young they’re entirely yellow, but once they mature they change completely. The front half of the body becomes light grey and the back half dark grey. Behind the eye they develop a long horizontal orange spot with a blue rim. The tail fin will develop stripes and spots and a white edge. As they grow older they generally become darker and on their throat and head they become more blue.

It can be aggressive towards other fish, especially other tangs and food competitors, but will make up for that with eating algae once hierarchy is established.

Like other tangs, it will eat meaty foods, but it's important it can graze on algae/seaweed the entire day to ensure it will stay healthy. So feed flakes/pellets multiple times a day and make sure there is always seaweed available.