The Leafy Sea Dragon
The leafy sea dragon (Phycodurus eques) is one of two species of sea dragon found in Australia’s southern waters and nowhere else in the world, the other being the weedy sea dragon. Despite its fearsome name, it is incredibly beautiful in shape and coloring and its camouflaging appendages give it a fragile appearance. It is a relative of the seahorse and belongs to the pipefish family Sygnathidae.
Leafy sea dragons get their common name from the leaf-like appendages on their bodies. They resemble floating pieces of seaweed, which makes them difficult for predators to find in their natural habitat. Most adults are green to yellowish-brown with thin bands or stripes across the body. They can reach a total length of 45 centimeters.
The leafy sea dragon lives among rocky reefs, seaweed beds, sea grass meadows and on sand patches near weed covered reefs where it looks like drifting seaweed. This species has only been recorded from the southern coastline of Australia.
The leafy sea dragon sucks up its prey using its long pipe-like snout and small mouth. Its favorite food is mysid shrimps or sea lice. These shrimps feed on red algae (seaweeds) that thrive in the shade of the kelp forests where the sea dragons live.
Being slow moving, they rely heavily on camouflage for survival, but are also equipped with several long sharp spines along the side of the body which are thought to be used to defend themselves against attacking fish. They are also able to change color to match their surroundings. Leafy sea dragons are fascinating to watch and their movements appear to mimic the swaying movements of seaweed and kelp. They steer and turn by moving the tiny, translucent fins along the side of the head and move through the water using the dorsal fins along the spine. They are one of the only animals in the world that hide by moving. Sea dragons have eyes that can move independently of one another, while one eye looks one way the other one can look in a completely different direction.
The most unusual fact about the leafy sea dragon is that the male gets pregnant and gives birth to live young. During mating the female lays 100 to 250 eggs onto a special brood patch on the underside of the male’s tail, where they are fertilized. During each breeding season, male leafy sea dragons will hatch two batches of eggs. The male incubates the eggs for 4-6 weeks and ‘gives birth’ to miniature juvenile versions of sea dragons. As soon as a baby sea dragon leaves the safety of its father’s tail, it is independent and receives no further help from its parents. At birth the young are around 20 millimeters long, which makes them vulnerable to predators like fish, crustaceans and sea anemones, only about 1 in 20 survive to become adults. But young sea dragons grow fast, reaching 20 centimeters after one year and reach their mature length at two years. It is not known how long wild sea dragons live. At the aquarium we have an exhibit dedicated only to leafy and weedy sea dragons with sea horses in our Living gallery section. They represent one of the most productive and plentiful on species region of the world’s oceans-Australia.