Which fish is in the picture?
The longhorn cowfish (Lactoria cornuta), also called the horned boxfish, is a species of boxfish from the family Ostraciidae, recognizable by its long horns that protrude from the front of its head, rather like those of a cow or bull. They are a resident of the Indo-Pacific region and can grow up to 50 cm (20 in) long.
Adults are reef fish, often solitary and territorial, and live around sand or rubble bottom up to a depth of 50 m (160 ft). They are omnivorous, feeding upon benthic algae, various microorganisms, and foraminiferans that it strains from sediments, sponges, polychaete worms from sand flats, mollusks, small crustaceans, and small fish, able to feed on benthic invertebrates by blowing jets of water into the sandy substrate.