Photo of Animalia: Sydney Cardinal Fish (species: Ostorhinchus limenus)

© John Turnbull

Mouthful of babies - Ostorhinchus limenus #marineexplorer

Some cardinal fish are mouth brooders - they protect their developing eggs by carrying them in their mouths. If you watch and wait long enough, they "aerate" the eggs by flushing water in and out of their mouths, sometimes requiring stray egg mass to be re-captured like in this shot at Fairy Bower, Manly. Note - this species used to be named Apogon limenus.

Photo taken on 22 Dec 2016