Leafy sea dragon

Natural history

The leafy sea dragon eats small shrimplike animals called mysids that live among the algae and seagrasses. A sea dragon’s tubelike mouth works like a drinking straw; a hungry dragon waits until its prey ventures near, then slurps it up. Each day, a single sea dragon may slurp up thousands of mysid shrimp.

Conservation

The seagrass and seaweed beds in Western Australia, where the leafy sea dragon lives, are under increasing threat from pollution and excessive fertilizer runoff.

In the past, unscrupulous collectors stripped habitat areas bare in their search for leafy sea dragons to sell to the pet trade, and for use in Asian medicines. Today, the leafy sea dragon is protected in both south and western Australia. The south Australian government allows one brooding male to be collected each year. The captive-bred hatchlings are sent throughout Australia and overseas for education and research programs such as ours here at the Monterey Bay Aquarium.

Cool facts

• As with its seahorse kin, a male leafy sea dragon carries its mate’s eggs until the eggs hatch.
• But unlike seahorses, male sea dragons don’t have a pouch. Instead, a male sea dragon carries the eggs on the underside of its tail in a brood patch that develops as mating season approaches. The brood patch contains capillaries that deliver oxygen-rich blood to the cuplike tissue.
• The female sea dragon transfers up to 300 eggs to the male’s brood patch, where the male fertilizes the eggs. The male cares for the eggs until their birth approximately four weeks later. Newborns, equipped with enough yolk to sustain them for two to three days, are on their own from the start. Once they deplete their yolk, the newborns must find their own food sources such as zooplankton and baby mysids.
• At birth, leafy sea dragons are only around .8 inches (20 mm) long. Within one year, they can grow up to 7.9 inches (20 cm). They reach their mature length within their first two years of life.