Threefin Velvetfish

Interesting Info

• The Threefin Velvetfish is a very small, secretive velvetfish with a unique triple dorsal fin arrangement that gives it its name.
• It is found in the Indo-West Pacific, including Queensland in Australian waters.
• This species belongs to the velvetfish family (Aploactinidae), known for their rough, velvety skin and masterful camouflage.
• Its body is mottled brown, orange, or grey with frilly flaps of skin that help it blend into rubble, sponges, and corals.
• The three separate dorsal fins are a key feature, distinguishing it from other velvetfish which usually have just one.
• Like its relatives, it is an ambush predator that waits motionless for prey, then snaps up small crustaceans and fishes with lightning-fast strikes.
• They live in coral rubble, sponge gardens, and algal patches on shallow reefs, usually down to 20 m (65 ft).
• Juveniles look very similar to adults but are even harder to spot because of their smaller size and mottled colours.
• Their venomous dorsal spines act as a defence, delivering a painful sting if handled carelessly.
• Little is known about their breeding, but they probably lay sticky eggs that attach to reef surfaces until hatching.
• The lifespan is unknown but is likely short, only 2–3 years like other tiny reef-dwelling fishes.
• Predators include larger reef fishes, octopuses, and small reef sharks, though their camouflage helps keep them hidden.
• Because of their size and cryptic habits, Threefin Velvetfish are very rarely seen by divers or snorkellers.
• This species is considered rare and is mostly known from scientific surveys rather than regular observations.