Stegastes arcifrons

The beaugregory is a small damselfish of the western Atlantic, typically found on shallow reefs and rocky outcrops from a few metres down to around 20 metres. It is dark brown or black with a bright blue spot or stripe on the cheek and blue edging on the fins—markings that stand out sharply against its plain body. Like other Stegastes damselfish, it is fiercely territorial and will chase away fish many times its own size to defend algae gardens on the reef. Divers often see it hovering near crevices or coral heads, ready to dart back into cover if threatened.