Aulopids are related to the salmonid group of fishes, sharing a characteristic, small fleshy adipose fin in front of the tail. The sergeant baker can be recognised by a mottled red elongate body, a salmon-like large head and jaws with several rows of fine teeth. Males differ from females by having greatly extended dorsal fin rays, measuring nearly half the body length. An inquisitive species, the sergeant baker remain perched on their ventral fins on the substrate with their head raised for much of the day. They are ambush predators and can attack at great speed from resting position, preying upon small fishes, crustaceans and molluscs. The sergeant baker grow to a maximum length of 69 centimetres.
Sergeant baker are the only species in the genus Aulopus that occupy a shallow habitat. They are relatively common on shallow rocky reefs with rich invertebrate growth around southern Western Australia and New South Wales, and venture into deeper waters, up to 250 metres, in other states. They are endemic to Australian temperate waters from Coral Bay, WA to Laguna Bay, Qld and northern Tasmania.
Occurrence at the Busselton Jetty:
Sergeant baker are occasionally observed from the underwater observatory. They are one of several fish species that perch on their ventral fins among the fallen debris and algae.
Image by: O. Rynvis