The western talma is distinctly shaped with triangular dorsal and anal fins. They are variable in colouration from shiny silvery to brown with five vertical, black bands down the body. Small juveniles have more rounded fins and a large white ocellus (or “false eye”) on the dorsal fin, which disappears upon maturity. These “false eyes” which are present in many juvenile fish species are thought to be a defensive strategy against predators, which may not attack the fish if they think the fish is looking at them. They have along, pointed snout, brush-like teeth and an eye which is obscured by the first vertical dark stripe, another strategy to confuse predators. The western talma grows to a maximum length of 26 cenitmetres.
The western talma occurs on sheltered coastal rocky reefs in southwestern Australia to 40 metres depth, ranging from Shark Bay, WA to Robe, SA. They commonly occur in pairs, which move slowly over the reef consuming small invertebrates, including soft coral polyps.
Other common names include: Truncate coralfish, squareback butterflyfish, coralfish, truncate butterflyfish, southern butterfly.
Occurrence at the Busselton Jetty
The western talma is a common species to frequent the waters surrounding the Busselton Jetty, and is observed on a daily basis from the underwater observatory. Both juveniles and adults are seen, mainly from the seafloor, as they constantly flit around the invertebrate adorned jetty piles feeding predominantly on the soft coral polyps of Telesto.
Image by: S. Teede