Dagger Tuskfish

Interesting Info

• The Dagger Tuskfish occurs in Australia from the Houtman Abrolhos to Scott Reef (Western Australia), at Ashmore Reef in the Timor Sea, and from the northern Great Barrier Reef south to the Solitary Islands in New South Wales; juveniles sometimes reach as far south as Barunguba (Montague Island) in southern NSW.
• Globally, it is a western Pacific species recorded from the Ryukyu Islands south through Indonesia and Papua New Guinea, east to Samoa and Tonga.
• It’s easy to recognise underwater by the broad yellow stripe along the side that darkens towards the tail and by a large pale oval patch below the rear of the dorsal fin.
• Adults also have a dark edge along the top of the tail fin — another quick field mark used by divers.
• Females and initial-phase fish are slender and more vividly striped; terminal-phase males are typically a little larger and deeper-bodied.
• Like other tuskfishes, it has strong front “tusk” teeth for nipping and crushing small bottom-dwelling prey.
• Diet consists of small benthic invertebrates (such as crustaceans and molluscs) picked from sand, rubble, and small coral heads.
• It forages by day over sand-and-rubble edges of reefs and shelters in crevices at night.
• This species is a protogynous hermaphrodite — individuals start life as females and some transition to males as they mature.
• Spawning occurs as distinct pairs in open water; eggs are released to drift with currents.
• Nest construction behaviour has been documented in this species in Okinawa, highlighting complex breeding behaviours in small tuskfishes.
• It lives on coral reefs and adjacent sand and rubble zones; juveniles often use sheltered patches and low coral heads.
• The species name honours American ichthyologist David Starr Jordan, reflected in the alternate names “Jordan’s Tuskfish” and “Jordan’s Wrasse.”
• Because of its small adult size, it has little value to fisheries, but it appears occasionally in the marine aquarium trade.
• As a small reef predator on invertebrates, it helps keep snail, crab, and other benthic populations in check.
• The Dagger Tuskfish lifespan is not well documented, it’s such a small wrasse, experts think it probably only lives a handful of years.