Weedy Seadragon – Victoria’s Marine Faunal Emblem
All of Australia’s living marine treasures are special – but there is a very special resident found only in southern Australian waters. This is the weedy seadragon.
Weedy seadragons (Phyllopteryx taeniolatus) are of superstar status in aquariums around the world. These photographs show the prestige and value weedy seadragons have in aquariums such as Sentosa Island in Singapore, and Ocean Park in Hong Kong (below).
When Jeff Weir, DRI’s Director, visited various marine institutions in USA, he was both proud and fascinated to see how our marine emblem is recognised throughout the world. He took this photo (below) at the Monterey Aquarium in California.
Weedy seadragons are members of the family Syngnathidae (pronounced SING-NAY-THID-AY) and have been Victoria’s marine faunal emblem since 2002.
The beautiful weedy seadragon is Victoria’s marine equivalent of Leadbeaters possum, helmeted honeyeater and pink heath (our other state emblems). Unlike those species that are threatened or endangered, we can, thankfully, still see weedy seadragons in our bays. The wonderful weedy seadragons live and reproduce right here in the bay of a major industrial city.
Its scientific name is Phyllopteryx taeniolatus, and it’s also known as Lucas’ seadragon or the common seadragon (to which the Australian Museum has changed its standard name, but for the time being, is keeping its old name; the weedy seadragon). It is a member of the Syngnathidae family, that also includes the leafy seadragon, seahorses, pipefish and pipehorses.
Weedy seadragons are closely related to the seahorse, and so the males carry the eggs! But unlike seahorses, their tails are non-prehensile and more elongated. Prior to the annual mating (usually in late spring), the weedy seadragon male’s tail becomes slightly swollen, spongy and soft. The female lays her bright-pink eggs here during mating, where they are fertilised. The males don’t hold their eggs in a brood pouch like seahorses, but carry them under their tails for about 2 months. The eggs (300 or so) hatch over 6 days, and are spread over a large area.
The young are like miniature versions of their parents, but only 2.5cm long. After 3 weeks, they’re nearly 7cm, and within 2 years, they reach their mature size of up to 46cm. These juvenile weedy seadragons below were photographed at Portsea pier.
They can live up to 10 years in the wild: main predators are habitat destruction, marine pollution, and the international aquarium trade. They are fully protected throughout all Australian waters.
Weedy seadragons are endemic to southern Australian temperate waters; but can be found as far away as Geraldton (WA) to Port Stephens (NSW). They can occur in depths of 50m, but usually live in waters deeper than 10m, and, commonly in sheltered areas such as kelp forests, seaweed beds, reef edges, around piers and in seagrass meadows. They are not strong swimmers, and are often washed ashore during storms or rough weather.
These delicate creatures seem to mainly feed on plankton, sealice, larval fishes and mysids (small shrimp-like crustaceans) through their long, thin, tubular snouts. Through these they use powerful suction to draw in water and their prey into their small, terminal mouths.
Weedy seadragons are camouflaged by long, leaf-shaped skin flaps that ‘sprout’ along the top and bottom of their bodies. With their dorsal fin and small fins either side of their head, they use these appendages to move somewhat awkwardly in the water; beautifully mimicking the sway of seaweed in the currents.
Colours along the weedy seadragon body are mainly orangey/red, with numerous white/yellow spots and iridescent blue/purple stripes. Their head is at a slight down-wards angle, and the mature females have deeper and more compressed bodies, which makes them somewhat easier to identify from the thinner-bodied males.
Despite the travails of industrialisation in the 20th and 21st centuries, these lovely creatures continue to live and reproduce in Port Phillip and Western Port. In many ways our bays are healthier than they were 50 years ago thanks to the efforts to reduce the impacts from sewage and stormwater. However, increasing population and the changing climate are increasing the risks of problems such as toxic algal blooms undoing some of the progress we have made.
Marine treasures like our wonderful weedy seadragons provide a strong sense of “why” we need to be concerned. Programs such as Waterwatch, Healthy Waterways, Coastcare and our own ‘i sea, i care’ all work with the community to help improve how we live in the catchment.
As the saying goes ,“Treat ‘em mean – keep your boat clean”.
This message is vital for all users of Australia’s marine ecosystems the year round. We should all know what to do when we see anyone doing the wrong thing on the water.
Report any suspicious behaviour on the following phone numbers.
Victoria 136 186 NSW 131 555 Queensland 13 74 68 Tasmania 130 368 550
NT 1800 453 210 WA 08 9474 9055 SA 1300 650 411
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