The Pinnatus Batfish (Platax pinnatus), also known as the Longfin Batfish, Pinnate Spadefish, Dusky Batfish, or Red-faced Batfish, is a species of marine ray-finned fish belonging to the family Ephippidae.

Distribution and Habitat

The Pinnatus Batfish is found in the Indo-West Pacific. The confirmed range is in the western Pacific from the Ryukyu Islands south to Australia. The adults are found under the overhangs of steep outer reef slopes down to depths greater than 20 meters. The juveniles are found among mangroves or sheltering in caves and under ledges in inner protected reefs.

Physical Description

The Pinnatus Batfish adults have a round strongly compressed body which has a depth of twice the length of the head. This species reaches a maximum published total length of 45 cm (18 in). Larger adults with a standard length in excess of 35 cm have a protruding snout and a concave dorsal profile of the head. The dorsal fin is supported by 5 or 6 spines and between 34 and 37 soft rays while the anal fin contains 3 spines and 24 to 28 soft rays. The dorsal, anal and caudal fins are yellow. Juveniles are dramatic in appearance with deep black bodies outlined in brilliant orange-red fins, and they mimic toxic flatworms by colour and shape.

Diet and Feeding

The Pinnatus Batfish feeds on algae as well as jellyfish and other gelatinous zooplankton. This species has been observed to significantly reduce algal growths on coral. In captivity it accepts a varied diet including marine algae, mysis shrimp, and frozen preparations.

Behavior and Reproduction

Pinnatus Batfish 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.

Aquarium Care

The Pinnatus Batfish is kept in aquaria but is difficult to maintain. It requires a large tank of at least 150 gallons with stable water conditions. It is generally peaceful but not considered reef-safe as it may nip at corals. Juveniles are particularly delicate and require excellent water quality and careful acclimation.

Conservation Status

Classified as Least Concern by the IUCN Red List.