Occurrence at the Busselton Jetty
Cobbler are a very rare sighting from the underwater observatory.
The Cobbler is yellow to dark brown with pale mottling over the back and sides, usually progressively darker towards the tail. It has a large flattened head and a long eel-like body that tapers to a pointed tail, with continuous dorsal, caudal and anal fins, attaining a maximum length of up to 91 centimetres. The broad mouth is surrounded by four pairs of highly sensitive sensory barbels (feeler-like tentacles), with a fifth pair of barbels present above the snout. Several serrated venomous spines are located at the front of the pectoral and dorsal fins and these can inflict a very painful wound.
Found in estuaries and silty bays of temperate marine waters from the Houtman Abrolhos, WA to southern QLD and northern Tasmania, Cobbler prefer areas where the bottom is sandy and weeds provide some cover for their nesting burrows where it remains concealed in this habitat during the day. Foraging for food at night the cobbler are an opportunistic feeders, primarily feeding on molluscs (bivalves and gastropods), crustaceans (prawns and amphipods), polychaete worms, algae and organic debris.
Cobbler are highly rated for their taste and are one of the most expensive fish species in Western Australia and for many years they have been fished both commercially and recreationally. However, the breeding habits of Cobbler have made them vulnerable to over-fishing. They reach sexual maturity around three years of age and 400mm in length, but in past years many immature fish were caught before they had an opportunity to spawn. Cobbler mate in pairs and spawn and nest in burrows under seagrass where the males remain nearby to guard eggs and rear the young. Unlike many fish which spawn prolifically and several times a year, Cobbler spawn only once per year, between September and November, and produce a relatively small number of eggs (500-3500). Today, there are size and bag limits applying to the take of Cobbler and they are totally protected in the Swan-Canning Rivers until 2017.
Recent studies suggest that Cobbler populations occupy a limited home range and there is little interbreeding. This means each of WA’s southern estuaries has a genetically unique cobbler stock and these distinct populations need to be protected in their own habitats.