There are dragons living in our seas and oceans, not the mythical fire breathing kind, but the beautiful and graceful almost fairy looking kind. I am talking about Sea dragons. Sea dragons are fishes that are within the same family of the seahorses and there are three species of sea dragons the Weedy Sea dragon (Phyllopteryx taeniolatus), the Leafy sea dragon (Phycodurus eques) and the in 2015 discovered Ruby sea dragon (Phyllopteryx dewysea).
Sea dragons can only be found along the southern coastline of Australia. Even though they are classified as a fish species they are remarkably bad swimmers. They spend most of their time swaying with the currents just like seagrasses and weeds. Sea dragons have three transparent fins, the two small pectoral fins are based on their neck and are used for positioning, the larger dorsal fin is used for propulsion.
Sea dragons don’t use their tail to hold on to branches or something else, unlike their seahorse relatives. The behaviour and ability of animals who use their tail to hold on to something for balance and such is called prehensile. Just like with the seahorses it is the males that take care of the young. However where seahorses keep their young in a little pouch in the belly, sea dragons keep the pink eggs fixed to the underside of his tail in a brooding patch. After an incubation period of 6 to 8 week the little sea dragons are born. When a baby sea dragon is hatched the baby leaves the safety of its fathers tail and are on their own. In the first couple of days they still have the yolk sacs attached to their body which they use to feed themselves. Later, they hunt small zooplankton, such as copepods, until they are large enough to hunt juvenile crustaceans.
Both the weedy and the leafy sea dragons prefer a habitat with lots of seagrass, kelp and seaweed for camouflage as they depend on this camouflage for protection against predators and to hunt for their prey (plankton and small crustaceans)
The Weedy sea dragon
Also known as the common sea dragon, the weedy sea dragon resembles (as the name suggest) seaweed. They have long thin bodies, which can reach a length of 30 to 45cm. they have long pipe-like snout with a small mouth. On their bodies they have leaf-like appendages which they have for camouflage. Weedy sea dragons are red/brown in colour with yellow and purple accents. They are usually found alone or in pairs at a depth of 10 to 50m.
The Leafy sea dragon
The leafy sea dragon are quite similar to the weedy sea dragon except for a shorter snout and more leaf like appendages. Leafy sea dragons are more brown/yellow in colour with olive coloured appendages. Leafy sea dragon reach a length of around 30 cm. They are found at a depth of 3 to 50m.
The Ruby sea dragon
Not much is known about this sea dragon it was only first described in 2015 when specimens were found on beaches in Australia. Its first live sighting was in 2017 when researches, who described this species, went looking for it through the use of a small remotely operated vehicle (ROV) round the islands of Recherche. Here they found two live specimens which they filmed.
Unlike its weedy and leafy relatives the ruby sea dragon hasn't got any appendages, this is because they prefer a different type of habitat, a more open sandy habitat in deeper waters (+50m). The ruby sea dragon is red in colour, this is probably its way to camouflage, as red wavelengths are not present in deeper darker waters, which would make them effectively invisible. Most deep sea creatures have a red body colour for this very reason. On the footage it seemed that the ruby sea dragon has the ability to hold on to something y using its tail, thus might have prehensile abilities. However this has not been proven.
Near threatened
Sea dragons are currently listed as near threatened. At the moment they are mostly under threat because of habitat loss and the pollution of their habitats. Previously divers would take the sea dragons from their habitat to keep in aquaria. How ever the Australian government put a stop to this practice in 1999 by making them a protective species.
Sources:
Rouse, G.W., Stiller, J., & Wilson, N.G., 2017. First live records of the ruby seadragon (Phyllopteryx dewysea, Syngnathidae). Available at: https://mbr.biomedcentral.com/articles/10.1186/s41200-016-0102-x
Weedy sea dragon image: https://www.scubadoctor.com.au/weedy-seadragons-melbourne.htm
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