Knife Wrasse

Interesting Info

• The Knife Wrasse, is a sand-dwelling wrasse found across the Indo-Pacific, including northern Australia, the Great Barrier Reef, Coral Sea, and offshore territories such as Christmas and Cocos (Keeling) Islands.
• Adults have a slender, blade-like body that gives them their common name, with a pale to greenish background colour and dark cross bars or blotches along the sides.
• A distinctive black blotch sits on the upper base of the tail fin, a quick way to identify this species from other razorfishes.
• Juveniles are much more colourful, often orange to reddish with vertical bars, and they mimic floating debris or drifting leaves to avoid predators.
• Like other razorfishes, they are masters of escape—diving head-first into sand in a split second whenever threatened.
• They are mostly solitary but can sometimes be seen in loose groups gliding across sandy lagoons or rubble flats.
• Knife Wrasses feed on small invertebrates such as shrimps, worms, molluscs, and brittle stars, which they snap up while hovering just above the sand.
• They are diurnal, active in the day and burying themselves at night to avoid nocturnal predators such as moray eels and snappers.
• Like many wrasses, they are protogynous hermaphrodites—starting life as females, with some later turning into males.
• Spawning occurs in pairs or small groups, with eggs released into the water column at dusk to drift away with the currents.
• The Knife Wrasse lives about 5–7 years in the wild, typical for medium-sized razorfish species.