Aiptasia-eating Filefish Identification Guide

Key identification features

• Small, laterally compressed, diamond-shaped body rarely exceeding 4 inches (10 cm)
• Mottled brown, tan, and olive coloring that shifts to blend with surroundings
• Skin covered in tiny filament-like appendages giving a soft, velvety or "hairy" texture
• Single slender dorsal spine that can be raised and locked upright, plus a small second dorsal and anal fin
• Small, high-set eyes and a tiny mouth with fused, chisel-like teeth
• Fins are mostly translucent, blending into the mottled body pattern

Common look-alikes

• Other small filefish species (such as the fringed filefish): lack the pronounced velvety, filament-covered skin texture that gives this species its "hairy" look.
• Juvenile leatherjackets: similar body shape but smoother skin without the fine hair-like projections.
• Pygmy filefish: generally smaller with less mottling and a more uniform pale color.

Where you'll see one

This filefish is found on shallow Indo-Pacific reefs, seagrass beds, and rubble areas, where its camouflage and slow, hovering swimming style let it blend into algae and soft coral while picking at small invertebrates.