Chromis atripectoralis

The black-axil chromis (Chromis atripectoralis), also known as the blackfin chromis or blue-green puller, is a damselfish from the tropical Indo-Pacific. This fish can reach almost 12 centimetres (4.7 in) in length. It inhabits lagoons and reefs, and often occurs in large numbers, feeding above Acropora corals. This fish mostly feeds upon copepods, amphipods, and zoea. This fish is often confused with Chromis viridis. It differs from this species by having a black blotch at the base of the pectoral fin when it mature.