This fish has been identified as Amblyglyphidodon indicus thanks for the help
Can anyone identify this Damselfish ? Only seen so far on the Tanzanian coast from Songo Songo Island to Dar es Salaam in Tanzania, doesn’t seem to be in Kenya or South Africa. So far seen only on shallow reefs 4 to 5 meters, just off the edge of the reef above large individual growths of Acropora corals. Has a very deep disc shaped body. Specimens in images are 6 to 7 cm in length. Looks like a Chromis but I cannot find it in any book.