Ringtail Cardinalfish

Found singly, pairs or small schools, sheltering during the day, dispersing at night to feed high above the reef, in silty lagoons and protected reefs.
Western Indian Ocean - Red Sea, Gulf of Aden

Males incubate their eggs inside their mouths, as the egg masses increase in size they can be found with wide open mouths where they shift the eggs around to aerate the egg masses.