Threadfin Cardinalfish

Found in dense schools often mixed with other fish, sheltering during the day, hovering above branches of Porites cylindrical coral or in caves and under ledges, dispersing at night to feed in turbid waters of bays and lagoons.
Widespread Indo Pacific

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.