Blackback Wrasse

Interesting Info

• The Blackback Wrasse occurs in Australia from the northern Great Barrier Reef and Coral Sea south to northern New South Wales.
• Globally, it is found throughout the tropical Indo-Pacific, from the Philippines and Indonesia to Papua New Guinea, New Caledonia, and Micronesia.
• It gets its name from the broad black or dark brown band that runs along its back from head to tail, contrasting with lighter, speckled lower flanks.
• Males are more brightly coloured than females, often showing greenish-blue highlights along the flanks and fins.
• Females and juveniles are more subdued, usually with a dark back and scattered pale speckles, blending well with coral rubble and algae.
• Like many wrasses, it is a protogynous hermaphrodite: individuals begin life as females before some transition into males as they grow larger and older.
• It feeds mainly on benthic invertebrates such as small crabs, molluscs, worms, and echinoderm larvae picked from sandy and rubble substrates.
• Foraging involves constant swimming and probing around coral rubble, often turning over small pieces in search of prey.
• The species is diurnal, spending daylight hours feeding before retreating to sandy burrows or reef crevices at night.
• Spawning occurs in pairs or small groups, with fertilised eggs released into the water column and left to drift with currents until hatching.
• The Blackback Wrasse has a relatively short lifespan compared to larger wrasses, living around 5–7 years in the wild.
• Predators include larger reef fishes such as snappers and groupers, though its speed and camouflage provide protection.
• Divers and snorkellers can identify it by the distinctive dark back and speckled sides, often seen darting around rubble slopes and reef edges.
• It plays an ecological role in controlling populations of small crustaceans and molluscs, contributing to the balance of reef ecosystems.