Leafy
Seadragon
The Leafy
Seadragon (Phycodurus eques) was adopted by the Government as the marine
emblem of South Australia on 8 February 2001.
The Leafy Seadragon's distribution is centred on South Australian coastal waters, ranging from Geraldton in Western Australia, along the southern Australian coastline, to Wilsons Promotory in Victoria. Under the Fisheries Act 1982 the Leafy Seadragon is a protected species in South Australian waters.
The Leafy Seadragon or "Leafy" as it is popularly known, is a relative of the seahorse and belongs to the pipefish family Sygnathidae. It is a unique and spectacular fish, being the only species of the genus Phycodurus. It is one of only two species of seadragons in southern Australia, the other being the Weedy Seadragon (Phyllopteryx taeniolatus).
The distinguishing and elaborate leaf-like appendages help to camouflage Leafy Seadragons among the seaweed. They can change their colour depending on age, diet, location or stress, although most adults are green to yellow-brown with thin, bands or stripes across the body. Being slow moving, they rely heavily on camouflage for survival, however they are also equipped with several long sharp spines along the side of the body which are thought to be used as a defence mechanism against attacking fish.
A unique characteristic of the seahorse, including the Leafy Seadragon, is the parenting role of the males. After male and female seadragons pair up in late winter, the female develops around 300 orange coloured eggs in her lower abdominal cavity and the male develops about 120 small pits or 'egg cups' on his tail. The eggs are transferred from the female to the male and fertilized, then carried by the male for an incubation period of about four weeks before young seadragons hatch over several days. At birth the young are around 20mm long and so highly susceptible to predation from fish, crustaceans and sea anenomes. The hatching itself is staggered to assist with dispersal and avoid competition for food amongst the young. The young dragons are fast growing, reaching 20cm after one year and attain mature length after about two years. It is not known how long wild seadragons live. Whilst they can reach up to 43cm in the wild the average size is closer to 30cm.
The Leafy Seadragon inhabits rocky reefs, seaweed beds, seagrass meadows and structures colonised by seaweed. They are highly susceptible to pollution and disturbance and loss of habitat is a major threat to their survival.
Fish such as the seadragon highlight the high degree of uniqueness or endemism of species that exists in southern temperate waters. Many Australians are not aware of the immense marine biodiversity they have off their southern coast.
