- English Name : Longnose filefish
- Local Name : Thundhigu fathirondu
- Size : Max. 10 cm
- Family : MONACANTHIDAE
- Order : Tetraodontiformes
- Distinctive Characters: Dorsal fin with 2 detached spines and 32-35 rays. Anal fin with 29-32 rays. Pectoral fin with 11 or 12 rays. Dorsal and ventral profiles - concave. Snouts lender and protruding.
- Colour: Green with numerous dark edged orange spots. A black blotch on caudal fin.
- Habitat and Biology: Occurs on protected areas of reef edge and slope to depths of 30 m. Often seen in
- pairs and sometimes in small groups amongst branched or tabular colonies. Feeds on coral polyps.
- Distribution: Indo-Pacific.
- Remarks: Oxymonacanthus longirostris can easily be distinguished from other Maldivian filefishes by its extremely long snout. It is closely related to O. halli, which is endemic to Red Sea. However, O. halli differs slightly in colour and has a lower fin ray count. A popular aquarium fish.