Seadragon Fact Sheet
- Habitat: Rocky reefs, seaweed beds, seagrass meadows and structures covered by seaweed and algae. Only found in the waters around Australia.
- Diet: Mysis shrimp, plankton, small crustatceans and fish
- Size: 12 inches to 18 inches
- Species: Two species, Phyllopteryx taeniolatus & Phycodurus eques
- Threats: Habitat loss, illegal poaching, pollution and industrial runoff, climate change.
The Sea Dragon is a most fascinating marine fish. It has a very unique and beautiful appearance. There are two species of Seadragons; the Leafy Seadragon and the Weedy Seadragon. Both of these are named after the characteristic leaf and weed like projections that come from their body. Often when people see the Sea Dragon they think it looks like something dreamed up in a fairy tale or science fiction book.
The Seadragon has a long, slender body. It comes from the same family as the Seahorse and Pipefish so it has the trademark long snout-like mouth. They have wing-like appendages that come from both sides of their body. The Weedy Seadragon (Phyllopteryx taeniolatus) are a reddish colored fish with yellow spots and purple-blue bars that can grow up to eighteen inches long. The Leafy Seadragon (Phycodurus eques) are mostly green in color and has more ornate appendages than the Weedy Seadragon. These Seadragons have very sensitive flotation bladders that can’t handle changes in water pressure or depth.
Unlike the Seahorse or Pipefish, the Seadragon is only found within the temperate coastal waters of Australia. The Weedy Seadragon lives within the shallow estuaries and deep offshore reefs along New South Wales. They prefer rocky reefs, seaweed beds, algae covered reefs and seagrass meadows. Often they live in water deeper than 33 feet. For younger, Weedy Seadragons they tend to stay within the kelp and sea grass regions.
On the other hand, the Leafy Seadragon often lives above sand patches, clumps of grass and kelp covered rocks around Victoria, South Australia and Western Australia. The Leafy Seadragon is typically found near seaweed since they can blend in with this environment the best.
Like the Pipefish and Seahorse, the Seadragon has a fused jaw and small mouth. They have no stomach so they need to eat throughout the day. They typically pull small mysis shrimp and plankton into their mouth. The food then quickly passes as waste. This means they can’t hold the food for energy and need to eat constantly to maintain their energy. In addition to small crustaceans, Seadragons also feeds on larval and small fish.
The Reproduction Process
The Seadragon typically reaches sexual maturity within two years. The female lays about 250 pink colored eggs that she places on the tail of the male. The eggs attach to a brood patch on the males tail, just as they do with Seahorses and Pipefish. Seadragons do not have a pouch, rather a spongy patch that runs along the base of the male’s tail.
The eggs become fertilized during the transfer from the female to the male. The male will then carry the eggs until they hatch. The time until the eggs hatch depends entirely on the water conditions, but 25-45 days is the average period for Weedy Seadragons, and around 100 days for Leafy Seadragons. After the young hatch they immediately become independent. They start off surviving on their yolk sack, but in a few days begin feeding on microscopic plankton.
Predators and Threats
The Seadragon’s primary defense is its camouflage. Their camouflage is so complete that the Seadragon has few natural predators in the marine environment. Since they can’t use their tail to grasp sea grass are vulnerable to rough conditions and often wash ashore after storms. Most dangers to a Seadragon come from humans.
Weedy and Leafy Seadragons were declared protected species in 1991 and can’t be taken from Australia without a permit. It is considered illegal to sell or transport Leafy Seadragons out of their natural habitat without a permission from the government. A small number of pregnant males are captured each year and give birth in captivity before being returned to the wild. These Seadragons are then hand reared and sold to public aquariums around the world.
Despite this protection, the biggest danger Seadragons face is from collectors who take the Seadragons for profits or as an addition to their home aquariums. The Seadragon is also a very delicate marine animal that is affected by pollution, habitat damage and loss. Even a slight change in the water pressure can cause a lot of damage to the Sea Dragon. Pollution and the discharge of industrial waste in the water is a big factor in the decline of Seadragons. Although not as common as the Seahorse and Pipefish, the Sea Dragon is still sometimes used in traditional Chinese medicines.
The Third Seadragon
A third syngnathid Haliichthys taeniophorus is sometimes called the Ribboned Seadragon is sometimes included in this group, but is more closely related to pipehorses. It’s other names include ribboned pipefish, and ribboned pipehorse. However, as seadragon is a common name and not a true taxonomic designation, there is really no correct answer to whether or not it is a seadragon. It is however more closely related to another group of fish called pipehorses. To confuse matters further, the weedy and leafy seadragons are both more closely related to pipehorses than each other.