Filefish

Filefish are marine fishes in the family Monacanthidae, named for their rough, file-like skin and characterized by a prominent dorsal spine that can lock upright.

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Triggerfish: Marine fishes in the family Balistidae, known for a locking dorsal spine and strong jaws. Their related locking-spine mechanism helps distinguish filefish within Tetraodontiformes.
Locking mechanism: A structure that holds a movable part in a fixed position until released. A smaller second spine braces the prominent spine in its raised position.
Orange-spotted filefish: A tropical Indo-Pacific filefish, Oxymonacanthus longirostris, that feeds chiefly on coral polyps. Its dependence on Acropora corals makes it especially vulnerable to reef degradation.
Pufferfish: Fishes in the families Tetraodontidae and related groups, several of which inflate when threatened. Pufferfish are close tetraodontiform relatives but lack the filefish’s locking dorsal spine.
Tetraodontiformes: An order of mostly marine fishes that includes pufferfish, triggerfish, boxfish, and filefish. Filefish belong to this diverse order of specialized fishes.
Labriform locomotion: Swimming powered mainly by oscillating the pectoral fins while keeping the body relatively steady. Filefish commonly maneuver with pectoral-fin strokes rather than strong body undulation.
Thread-sail filefish: A tropical Indo-Pacific filefish, Stephanolepis cirrhifer, with elongated dorsal-fin rays. It is a commercially caught species in parts of East Asia.
Boxfish: Marine fishes with rigid, box-shaped bodies formed by bony plates beneath the skin. Their armor contrasts with the flexible, rough-skinned bodies of filefish.
Dorsal fin: A fin on the back of a fish that helps stabilize its body while swimming. The first dorsal spine is the distinctive structure that can lock upright.
Pectoral fin: A paired fin behind a fish’s head, used for steering, braking, and propulsion. Its controlled strokes help filefish hover and maneuver around reef structures.