Sunday, February 20, 2011
February 20, 2011 : Leafy Sea Dragon
Leafy Sea Dragon
The leafy sea dragon or Glauerts Seadragon, Phycodurus eques, is a marine fish in the family Syngnathidae, which also includes the seahorses. It is the only member of the genus Phycodurus. It is found along the southern and western coasts of Australia. The name is derived from the appearance, with long leaf-like protrusions coming from all over the body. These protrusions are not used for propulsion; they serve only as camouflage. The leafy sea dragon propels itself by means of a pectoral fin on the ridge of its neck and a dorsal fin on its back closer to the tail end. These small fins are almost completely transparent and difficult to see as they undulate minutely to move the creature sedately through the water, completing the illusion of floating seaweed.
Much like the seahorse, the leafy sea dragon's name is derived from its resemblance to another creature (in this case, the mythical dragon). While not large, they are slightly larger than most sea horses, growing to about 20–24 cm (8–10 in). They feed on plankton and small crustaceans.
The lobes of skin that grow on the leafy sea dragon provide camouflage, giving it the appearance of seaweed. It is able to maintain the illusion when swimming, appearing to move through the water like a piece of floating seaweed. It can also change colour to blend in, but this ability depends on the sea dragon's diet, age, location, and stress level.
The leafy sea dragon is found only in the waters of Australia from Kangaroo Island on the Southern shoreline to Jurien Bay on the Western shoreline. It was once thought to be very limited in its range; however, further research has discovered that the sea dragon will actually travel several hundred metres from its habitat, returning to the same spot using a strong sense of direction. They are mostly found around clumps of sand in waters up to 50 metres (164 feet) deep, hiding among rocks and sea grass. They are commonly sighted by scuba divers near Adelaide.