Southern Sea Garfish
The Southern Sea Garfish is a slender open water fish with a triangular upper jaw and a significantly longer needle-like lower jaw. It is the largest species in the family found in southern Australia. Southern Sea Garfish are a pale bluish green above the lateral line and silvery below on the belly area, with a blue edged silver band along the middle of the sides. It is this counter-shading which aids greatly in camouflage and makes them barely visible to predators from both above and below the water’s surface.
Southern Sea Garfish are found in southern Australia from Lancelin, WA to Queensland, where they inhabit inshore surface waters (to 20 metres depth) of sheltered bays, coastal seas and estuaries.
Southern Sea Garfish are omnivores, where during the day floating seagrasses and algal filaments comprise approximately 75% of their diet, however they also tend to be opportunistic feeders and feed on amphipods, during their vertical migration, insects, smaller fishes and crustaceans at night. In turn they are a key link between trophic levels, where they are consumed by many ecologically and commercially important predatory fish, such as mackerel and sharks.
Southern Sea Garfish are egg layers and produce relatively small numbers of fairly large eggs in shallow coastal waters amongst seagrass meadows. During the first three years this species experience rapid growth reaching sizes of up to 30cm and after this time growth is considerably slower eventually reaching a maximum length of 52 centimetres. This species is known to live for approximately 9 years.
Other common names include Dusky garfish, Halfbeak, South Australian Garfish.
Occurrence at the Busselton Jetty
The Southern Sea Garfish is observed occasionally in the surface waters of the open water zone windows of the Underwater Observatory. It is much more commonly seen as a species caught by recreational fishers along the length of the Busselton Jetty.