A sea dragon is a fish that belongs to the Syngnathidae family along with sea horses and pipefishes. As with other members of the family, it has its jaws fused together in a tube-like structure, just as the name of the family implies. Its “dragon” name comes from its resemblance to the mythical creature often portrayed in various mythologies.
There are two types of sea dragons, leafy sea dragons (Phycodurus eques) and weedy sea dragons (Phyllopteryx taeniolatus). These two species live in the southern part of Australia, but the weedy variety lives on the coasts of Tasmania as well. Both species prefer coastal waters with depths of 50 m and below, and they usually stay around rocky reefs rich in seaweed.
Both species resemble sea horses, with the characteristic fused jaws and elongated bodies. The leafy sea dragon is the smallest, measuring 20 to 24 centimeters, while the weedy sea dragon can be as long as 45 centimeters. Both of these species have protrusions on their body which do not serve for swimming, their role being in providing the sea dragons with better camouflage in their habitat. The protrusions of the leafy sea dragon are wide lobes if skin which somewhat resemble leafs, while in the case of the weedy sea dragon, the protrusions are much smaller, complimented by a range of spines which are used for protection.
Sea dragons propel themselves not with their leaf-like protrusions, but with their dorsal and pectoral fins. As these are small in size and the movements are rapid, these animals create the illusions of floating in the water. This is complemented by their leaf-like skin protrusions, which not only provide them with better camouflage, but also make them appear as inert floating leafs on the sea bed.
Both sea dragon species feed on small crustaceans and zooplankton, which they suck in with the help of their elongated jaws.
Just as in the case of sea horses, sea dragon males are the ones responsible for taking care of the eggs. The females will deposit their eggs in the underside brood patch on the male’s tail, up to 250 in the case of leafy dragons and 120 for weedy sea dragons. The males will take care of the eggs until they hatch, becoming independent. Only 5% of the eggs survive, emerging into adults in two years.
Due to their slow swimming abilities and vulnerability when young, both sea dragon species are protected by law in many of the waters of South Australia.