Pinnate Batfish

Geographical Origin and Habitat: Western Pacific, ranging from the Ryukyu Islands to northern Australia and Indonesia. Inhabits coral reefs and sheltered coastal lagoons at depths of 2 to 30 meters.

Taxonomy and Morphology: Part of the Ephippidae family, genus Platax. Features a highly compressed, disk-shaped body. Reaches 45 cm (18 inches) in length and up to 60 cm vertically. Juveniles have elongated dorsal/anal fins.

Social Behavior: Peaceful, slow-moving, and easily intimidated. Juveniles mimic toxic flatworms by fluttering near the substrate. Adults are solitary or form small schools.

Coloration and Sexual Dimorphism: Juveniles display a velvety black body ringed by a bright orange-red border. Adults transition into a dull silver-grey with shortened fins. No distinct sexual dimorphism.

Aquarium Setup: Requires a very large and tall aquarium of at least 1000 liters (260 gallons) with an water depth of at least 80 cm to accommodate vertical growth. Rocks should be kept at the back.

Diet and Feeding: Omnivorous/carnivorous. Notoriously difficult to feed in captivity. Offer live brine shrimp, mysis, and fresh clam meat pressed onto rocks. Feed 3+ times daily.

Water Quality: Maintain stable marine parameters: temperature 22-27°C (72-80°F), pH 8.0-8.5, specific gravity 1.020-1.026, and KH 8-12. Highly sensitive to ammonia and nitrite.

Compatibility and Cohabitation: Not reef-safe; nips at soft corals, zoanthids, and anemones. Must be kept with peaceful, slow-moving tankmates. Fast feeders will outcompete this species.

Aquarium Breeding: Unachieved in private aquariums. In nature, they engage in open-water spawning with pelagic larvae.

Risks and Diseases: Extremely high mortality rate in captivity due to starvation. Prone to marine ich, velvet, and Lymphocystis virus under stress.