Seadragons are called leafy or weedy depending on the number and appearance of their distinctly plant-like appendages and are in the family Syngnathidae, sharing characteristics such as long tube-snouted mouths and bodies enclosed in bony plates with their more common cousins the seahorses (Hippocampinae) and pipefish (Syngnathine).  The Leafy Sea Dragon is one of the natural world’s undisputed masters of camouflage, blending perfectly with the surrounding kelp beds.

Description

The Leafy Seadragon, P. eques, is a spectacularly camouflaged fish found exclusively in macro-algae beds of southern Australia.  Leafy seadragons reach a length of approximately 35 cm and are covered with jointed, armour-like plates instead of scales.  Unlike its seahorse cousins, the leafy seadragon has a laterally flattened body and swims horizontally through the water column. "Leafies" are best known for the incredible skin filaments that hang off of their head, body and tail like so many blades of brown seaweed.  The body is protected by multiple long, sharp spines that run from the dorsal surface and enclose the body. When in deep water they are dark brown to burgundy red in colour whilst in shallow water are more yellow or greenish.

Range: The Leafy Seadragon is endemic to the temperate waters along the southern coast of Australia and is commonly found in South Australia, and in southern eastern Western Australia. The Leafy Seadragon occurs sporadically in Victoria to the east of South Australia and in southern western coast of Western Australia but is rare north of Perth the capital city (Kuiter 2000). The Leafy Seadragon  was initially believed to be restricted to an area ranging from Kangaroo Island in South Australia to Lancelim in West Australia (Hutchins 1986).  Recent observations have expanded this range roughly 800 kilometres east of Kangaroo Island and 100 kilometres north of Lancelim (Mackay 1998).

Distribution/Habitat: The Leafy Seadragon is endemic to the temperate waters along the southern coast of Australia living in and among the kelp-covered fringing rocky reefs. The leafy seadragon is superbly camouflaged and is found among three genera of brown algae, Macrocystis, Ecklonia, and Lessonia.  These algae comprise mid-littoral kelp beds.  Seadragons inhabit the mid-littoral zone, ranging in depth from roughly 5 to 35 meters, but prefer shallower depths of 5 to 15 meters.   Leafy Seadragon adults congregate in some shallow bays in late winter to pair and mate. 

Natural History:

Much of the information available about seadragons has come from studies of preserved species or recorded observations by recreational divers (Mackay 1998).  Researchers in Southern Australia have witnessed the seadragon "curling up" and presenting the spines to attacking fish (Flaherty 1997) The mortality rates for seadragons are believed to be relatively low for marine fish due to the amount of eggs produced per season and the general lack of predators who rely on them as a primary food source (Whitley & Allan 1958). When adult the Leafy Seadragons feed on various reef crustaceans including large shrimps and squat-lobsters (Kuiter 2000). 
The distinct lack of swimming apparatus make the seadragon a very poor swimmer but the leafy projections that hang from the head, body and tail aid in balance and buoyancy. 

Reproduction: Seadragons are thought to reproduce once per year, usually in August and September, and produce approximately 250 eggs (Whitley and Allan). 

Photos of Leafy Seadragon - Taken at Rapid Bay South Australia by Graham Short

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