We’re very lucky in Sydney to have a creature as beautiful as the weedy seadragon literally on our doorstep. Weedy seadragons are quite bizarre looking and yet they are very appealing. Despite being brightly coloured, they can often be difficult to spot amongst kelp unless you have a dive light. They make great subjects for photography and video.
Weedy seadragons are found right around southern Australia from the Sydney region on the east coast to the Perth region on the west coast and also around Tasmania. There’s a fair amount of variation in colouration of these fish between regions and it was once proposed that they were different species although they are all now classed as a single species.
In the Sydney region they are found from Port Stephens in the north to Bass Point in the south. They are also found right down the New South Wales coast including Jervis Bay and Bermagui. They tend only to be found at dive sites that are ocean facing or if they are in a bay, they are close to the mouth, like the heads of Sydney Harbour or around Kurnell.
Weedy seadragons are related to seahorses and pipefish and share the same family, Sygnathidae. Their general shape is similar to that of a seahorse although they have a more horizontal orientation like a pipefish. Individuals around Sydney get to a length of around 40 centimetres. Their scientific name is Phyllopteryx taeniolatus and they are the only species in their genus. Leafy seadragons from southern Australia are in a different genus.
Like seahorses and pipefish, it is the male that carries the eggs until they hatch. They don’t have a pouch like seahorses do and instead carry the eggs attached to their tail. According to Kuiter (2009), they mate in October and November, however, I have seen a male carrying eggs in August so either this was a second brood or their mating period is extending. Large males can carry up to 300 eggs per brood and they hatch after around 2 months. Newly hatched weedy seadragons are supposed to settle to the bottom but I have not been lucky enough to ever see any. I have seen juveniles that were 10-15 centimetres long.
One of the most reliable sites to see them is at Kurnell, where they can be seen at all three sites: The Leap, The Steps and The Monument. They are almost always at the sand line around or amongst kelp but may venture into the boulders. If you swim along the sand line you’re very likely to see at least one. It is best to carry a dive light as this lights up their colouration and makes them much easier to spot.
Other locations where they can be found include Bare Island, Magic Point, Shelly Beach, Coogee, North Bondi, Bass point.