What is "percophidae"

The Percophidae, duckbills, are a family of perciform fishes found in tropical and subtropical waters of the Atlantic and Indian Oceans and in the southwestern and southeastern Pacific.

They are small fishes: the largest species, the Brazilian flathead, Percophis brasiliensis, grows up to about 50 cm, but 10 to 20 cm is more typical. A few species are fished commercially, including the Brazilian flathead.