Phycodurus eques, commonly known as the sea dragon, are bright-colored fish endemic to the seas off Tasmania, South and East Australia. The Latin words phyko, which means seaweed, and oura, which means tail, are the origin of the name phycodurus. Eques is derived from the Latin word “equus,” which means horse. 

Sea dragons avoid predators thanks to their camouflage, and they feed on microscopic food like crustaceans and small fish, despite the fact that they lack teeth in order to survive.


Appearance

A form of pipefish, the Sea dragon has long, slender bodies and tails. Additionally, they have camouflage to shield them from predators. For instance, the leafy sea dragon can camouflage itself in kelp and seaweed thanks to its body being covered in leaf-like tendrils. Its olive-colored patches and yellow-to-brown pigmentation help it blend in with the aquatic vegetation where it lives.

Sea dragon swimming between sea weeds
Sea dragon swimming between sea weeds.

Credit: lecates

Two other varieties of Sea dragons exist. The weedy sea dragon only has a few appendages, but they are sufficient to assist in its environment-blending. Alternatively, the deep red ruby Sea dragon only has a few stumpy, extremely short limbs. Due to their weak swimming abilities, all three of these animal species have a tendency to drift with the currents.

Diet

Although Sea dragons are carnivores, the types of meat they may consume are constrained by the length of their mouths, which resemble long ducts. Sea dragons attack and consume any animals that they can fit in their mouths after hiding out and ambushing their victim. Some of their food sources are zooplankton, worms, small fish, crustaceans, and fish larvae.

They suck their prey in with a strong jaw suction to grab it. To give an idea, it is comparable as though food being sucked through a straw. They resort to this technique because they lack releasing jaws. The sea dragons may devour their prey entirely once it is in their mouths. 

Habitat

Only in the oceans of Southern and Western Australia and in the vicinity of Tasmania can one encounter Sea dragons. Across the board, sea dragons inhabit in or close to seaweed, mangrove forests, rocky reefs, and seagrass beds; however, they commonly move around.

A sea dragon in its natural habitat camouflaged in kelp.
A sea dragon in its natural habitat camouflaged in kelp.

Credit: John Turnbull

They are often found in shallow coastal areas but may sometimes be found up to 150 ft below the sea, reachable only by scuba diving. The fact that ruby sea dragons have been found dwelling in considerably greater depths than the other species could be the reason why they were just recently identified. 

Reproduction

Male Sea dragons bear the young, just like sea horses do. But unlike sea horses, which have a pouch, male Sea dragons have a spongy brood patch under their tails, which is where females lay their bright-pink eggs during mating.

Sea dragon females can produce as many as 300 eggs at a time. In the process of moving from the female to the male, the eggs are fertilized. The eggs are incubated and carried to term by the males, who then release the baby sea dragons into the water after around 4 to 6 weeks. 

A leafy sea dragon in an aquarium
A leafy sea dragon in an aquarium

When the offspring are known as fry hatch, they resemble miniature versions of their parents but without any of the adult’s camouflaging appendages.

Threats

Unknown predators, if any, pose a threat to Sea dragons. Additionally, they have a lot of bone, which may make them less alluring to predators than other fish. The loss of habitat, particularly seaweed and seagrass beds, is a major danger to the survival of these creatures. 

Human activities, notably pollution, as well as the changes brought on by global warming, are to blame for this. Additionally, people have taken these species and kept them as aquarium pets, thus reducing their numbers. Fishing nets do occasionally entangle sea dragons, and when this happens, they often perish.

Facts about the Sea dragon

  • Sea dragons don’t have a direct predator.
  • They are recognized as a Totally Protected Species in South Australia.
  • Since they are shy creatures, when encountering a human, they drift away.
  • Sea dragons are completely harmless to humans.
  • Just like scuba equipment, sea dragons use swim bladders to maintain buoyancy.


FAQs 

What is the lifespan of Sea dragons?

A Sea dragon’s lifespan ranges from 3 to 10 years, with 5 or 6 years being the average. Granted, this number is dependent on whether the Sea dragons are in captivity or in the wild and other variables related to threats and the environmental ecosystems.

How big do Sea dragons grow?

Sea dragons may grow up to one foot or 30 cm long, which is relatively huge compared to the size of species that are closely related to them. Their otherworldly appearance might have been the inspiration for many sea monster stories.

What is the oldest sea dragon?

Researchers found an incredibly old fossil that was identified as a Sea dragon. This specific fossil, which was recovered almost completely, is about 33 ft long and probably dates back 180 million years. Leading scientists to believe that the sea dragon species was significantly bigger than their present state.

Can Sea dragons hurt humans?

Seeing as Sea dragons do not possess sharp teeth or any venomous properties, they can’t hurt a human. These species rely heavily on camouflage in order to avoid confrontation with bigger predators. They also rely on ambushing smaller species to acquire sustenance successfully.

What are Sea dragons known for?

Sea dragons drift in the water and, thanks to their leaf-like appendages, mimic the swaying seaweed of their habitat. They are not known for any notable speed; on the contrary, they are slow-moving. Similar species may grasp and attach themselves thanks to a prehensile tail, which Sea dragons lack.