Reef Filefish

The Reef Filefish is a small and exquisitely beautiful species closely related to the more commonly encountered Longnose Filefish (Oxymonacanthus longirostris). It shares the same elongated snout and laterally compressed body shape but displays slightly different coloration, typically showing a green to blue-green body with orange spots and a more robust build than its congener. This species is highly sought after by advanced aquarists but is notoriously difficult to maintain in captivity.

The primary challenge with the Reef Filefish is its highly specialized diet. In the wild, this species feeds almost exclusively on Acropora coral polyps, picking individual polyps from branching coral colonies with its elongated snout. This obligate corallivorous diet makes long-term captive maintenance extremely difficult, as most specimens slowly decline without access to live coral polyps. Some dedicated aquarists maintain dedicated coral frag systems specifically to supply food for this species.

Due to its extreme dietary requirements, the Reef Filefish is recommended only for expert aquarists who are prepared to provide live coral as a food source or who have had success weaning similar species onto prepared foods. A small aquarium of 30 gallons is sufficient given its diminutive 4-inch maximum size, but the fish must be housed with an ample supply of Acropora or other SPS coral colonies. Ironically, while it requires reef conditions to thrive, it is decidedly not reef-safe as it will consume the very corals it depends upon.