Batfish

Platax pinnatus, also known as the longfin batfish, pinnate spadefish, pinnate batfish, pinnatus batfish, dusky batfish, shaded batfish, or red-faced batfish is a species of marine ray-finned fish belonging to the family Ephippidae, the spadefishes and batfishes.

This species is found in the western Pacific Ocean and occasionally is kept in marine aquariums. The confirmed range is in the western Pacific from the Ryukyu Islands south to Australia. In Australia it has been recorded from off the central coast of Western Australia, around the tropical northern coasts and south along the east coast to the central coast of New South Wales. The adults are found under the overhangs of steep outer reef slopes down to depths greater than 20 m. The juveniles are found among mangroves or sheltering in caves and under ledges in inner protected reefs.

Platax pinnatus adults have a round, strongly compressed body which has a depth of twice the length of the head. Larger adults, with a standard length in excess of 35 cm. The juveniles are mainly black with the body and median fins outlined in orange. This species reaches a maximum published total length of 45 cm.

Platax pinnatus adults are normally solitary but will gather in large schools to move over open substrates.The juveniles are mimics of a toxic species of flatworm by colour and shape. They feed on algae as well as jellyfish and other gelatinous zooplankton. This species has been observed to significantly reduce algal growths on coral in studies simulating the effects of overfishing on the Great Barrier Reef.