Batfish have deep, rounded laterally compressed bodies. In juveniles the dorsal and anal fins are extraordinarily long, but these become proportionally smaller as the fish grows.
Juveniles are found in sheltered habitats such as mangroves and inner reefs, whilst adults live on the reef to depths of at least 20m, generally in steep areas with large overhangs which provide them with shelter.
They are omnivores as they eat algae and small invertebrates on the reef surface.
Batfish live on their own rather than in schools.
The pinnate batfish is distinguished by the concave profile of its snout. In other species it is more rounded. The pinnate batfish grows to about 50cm and the juvenile is easily recognisable by the bright red margin around its fins and body. In the adults this margin turns to a dull silver.
The pinnate batfish is a poor choice of fish for an aquarium as they typically die within the first few days in the aquarium. Even compared to other batfish the pinnate batfish are known for being frail and fragile. The few that do survive in an aquarium past their juvenile stage lose their juvenile colouration and exhibit an adult colour which many people find considerably less attractive.
In the wild the pinnate batfish has been observed to significantly reduce algal growths in studies simulating overfishing on the great barrier reef.