The leafy sea dragon, Phycodurus plicatilis, is a species of fish native to coastal waters in Australia. They are found along the east coast of New South Wales and Queensland. They feed primarily on crustaceans such as crabs, shrimp, lobsters, prawns, crayfish, shrimps, mantis shrimp, and amphipods. They have been known to eat small fishes and even juvenile sharks.
An overview
The “leafy seadragon”, also known as the “sea dragon”, is one of several species of seadragons. Its scientific name is Diplocynodon pectoralis. Like other seadragons, it belongs to the class Orectolobiformia, meaning that it is related to both sharks and rays. This group includes the skates and guitarfish.
The leafy seadragon grows to about 8 inches long, though some specimens reach 10 inches. It is found throughout much of the tropical Indo-Pacific region, including Australia, New Guinea, Indonesia, Malaysia, Philippines, Papua New Guinea, Solomon Islands, South China Sea, Taiwan, Thailand, Vietnam, and Western Pacific Ocean. In the United States, it lives along the Atlantic coast from North Carolina southward; in Hawaii, it occurs off southern California, Florida, and the Caribbean islands. It is sometimes called the “seaweed dragon”.
Like many seadragons, the leafy seadragon feeds mainly on shrimp and small fish. It hunts by moving rapidly through the water column, capturing prey with its sharp teeth. When threatened, it inflates itself, creating a bubble around itself that resembles a mushroom cloud. It uses this technique to escape predators such as barracuda, jacks, and hammerheads.
Although the leafy seadragoon does not swim very fast, it is capable of making short bursts
Geographic Distribution and Habitat
Coastal waters off the states of West Australia, South Australia, Victoria in Southern Australia are known to host large populations of dugongs. Dugong populations are threatened due to habitat loss, pollution, overfishing and entanglement in fishing lines.
The species is listed under Appendix I of CITES, making international trade illegal. In addition, there is no legal protection for dugongs within Australian jurisdictions. There is little information about the current status of dugongs in the region.
The seadragon is a large species of marine fish belonging to the family Syngnathidae. It lives in shallow coastal seas throughout Australia, New Zealand, Papua New Guinea, Indonesia, Malaysia, Singapore, Thailand, China, Japan, Korea, Taiwan, India, Sri Lanka, Madagascar, Mauritius, Seychelles, Reunion Island, Réunion Island, Vanuatu, Fiji, Samoa, Tonga, New Caledonia, French Polynesia, Hawaii, Easter Island, Chile, Argentina, Uruguay, Paraguay, Brazil, Venezuela, Colombia, Ecuador, Peru, Mexico, Costa Rica, Panama, Nicaragua, Cuba, Jamaica, Trinidad & Tobago, Barbados, Bermuda, Puerto Rico, Turks & Caicos Islands, Virgin Islands, Saint Martin, Saint Barthélemy, Saint Kitts & Nevis, Saint Lucia, Saint Vincent & Grenadines, Antigua & Barbuda, Dominica, Bahamas, United States, Canada, Greenland, Norway, Sweden, Denmark, Finland, Iceland, Ireland, Isle of Man, Scotland, England, Wales, Jersey, Guernsey, Isle of Wight, Channel Islands, Faroe Islands, Malta, Algeria, Tunisia, Libya, Egypt, Morocco, Oman, Yemen, Saudi Arabia, Kuwait, Bahrain, Qatar, UAE, Iraq, Jordan, Israel, Palestine, Syria, Lebanon, Cyprus, Greece, Turkey, Bulgaria, Romania, Croatia, Serbia, Montenegro, Macedonia, Albania, Kosovo, Bosnia & Herzegovina, Slovenia, Hungary, Poland, Czech Republic, Slovakia, Estonia, Latvia, Lithuania, Germany, Austria, Switzerland, Liechtenstein, Luxembourg, Italy, Monaco, San Marino, Andorra, Vatican City, Gibraltar, France, Belgium, Netherlands, Luxembourg, Spain, Portugal, Finland, Sweden, Denmark, Norway, Iceland, Ireland, Great Britain, Northern Ireland, Scotland, Isle of Man, Channel Islands, Faroes, Faeroe Islands, Malta, United Kingdom, Channel Islands, Guernsey, Jersey, Isle of Man, Isle of Wight.
Ecology
Leafy seadragons feed on small crustaceans, plankton, and larvae of fish through their long, pipe-like nose. They use their fins like hands, grasping prey with their pectoral and pelvic fins. Their eyesight is poor; however, they do possess good hearing.
The species lives alone most of the time, except during mating season. Male leafy seadragongs gather together in groups called “camps”, where they compete for dominance. Females choose one male as her mate, and he guards her while she lays eggs. After spawning, the female leaves the nest, and the male continues guarding it until his offspring hatch. He stays by the nest for about three months. If there is no food around, he goes out into deeper waters.
Once the young hatch, they remain close to the parent for another six weeks. During this period, they eat mostly zooplankton and small organisms. Once they reach sexual maturity, they begin to disperse. At this stage, the young seadragon spends much of its life floating in open water.
Reproduction
The male leafy seadragong lays up to 250 eggs on the female’s tail. She then deposits them onto the males’ tail with her ovipostion, a long tube. The eggs are attached to a brood patch, a small area of skin near the base of the tail, where they receive oxygen. They develop into larvae within 10 days. When the larvae reach about 2 cm in length, they wriggle free of the egg case and swim away. A few days later, the larvae metamorphose into juvenile seadragons. The juveniles grow rapidly during the next three months and become sexually mature around nine months old. At this stage, the females lay eggs again.
Movement
The leafy seadragon is a species of fish native to Australia. They are found in shallow coastal waters, usually near coral reefs. Their name translates into English as “sea dragon.” Like many marine animals, they do not breathe air; rather, they use gills to extract oxygen from seawater.
Leafy seadragons are typically nocturnal and spend most of their lives hiding under rocks during daylight hours. When disturbed, they will quickly swim away, often turning around to face their attacker. If threatened, they will raise their dorsal fin and hiss loudly. Leafy seadragons eat small crustaceans and worms.
Conservation
The leafy seadragon is one of the most threatened marine reptiles in the world. These creatures are found along coastal waters around the globe. Their habitat ranges from tropical reefs to temperate lagoons. While some populations live in healthy numbers, others are dwindling due to overfishing, pollution, development, and climate change. As a result, the International Union for Conservation of Nature lists the leafy seadragon as critically endangered.
Leafy seadragons face many threats, including those posed by humans. Some people collect the animals for display in tanks. Others harvest them for use in traditional medicine. Still others hunt the creatures for food.
In addition to being threatened by human activity, the leafy seadragons themselves face danger. When the young hatch out of eggs, they are small and helpless. If they aren’t picked up immediately, they drown. This makes it difficult for the young to escape predators like sharks and large fish.
A few species of leafy seadragon are already extinct. However, scientists say there are still enough remaining individuals to make recovery efforts worthwhile.
Population
Leafy sea dragons are endemic to the waters off south-east Australia. They’re closely related to seahorse and pipefish. These creatures are generally brown to yellowish in body color with spectacular green-olive tinted appendages. They live close to shore where there is plenty of food, such as algae, krill, small fish and invertebrates. While some species spend most of their lives out of water, others come up onto land to mate. Like many animals, leafy sea dragon populations are declining due to overfishing and habitat loss.
Size
The maximum length of the leaf-shaped seadragon is about 14 inches. The species lives in tropical waters around Australia, New Guinea, Indonesia, Malaysia, Sri Lanka, India, Pakistan, Bangladesh, Cambodia, Vietnam, Thailand, China, Japan, Taiwan, South Korea, Philippines, Singapore, Papua New Guinea, Fiji Islands, Samoa, Madagascar, Mauritius, Seychelles, Reunion Island, Réunion Island, Kenya, Tanzania, Mozambique, Malawi, Zambia, Zimbabwe, Angola, Namibia, Botswana, Swaziland, Lesotho, South Africa, Antarctica, Chile, Argentina, Uruguay, Paraguay, Brazil, Venezuela, Colombia, Ecuador, Peru, Mexico, Guatemala, Costa Rica, Panama, Cuba, Jamaica, Trinidad & Tobago, Saint Vincent & Grenadines, Dominica, Martinique, Guadeloupe, Antigua & Barbuda, Saint Lucia, Belize, Honduras, El Salvador, Nicaragua, Bermuda, Turks & Caicos Islands, United States Virgin Islands, Puerto Rico, Virgin Islands, French West Indies, British Virgin Islands, Cayman Islands, Bahamas, Barbados, Dominican Republic, Haiti, Montserrat, Anguilla, Aruba, Curaçao, Sint Maarten, Netherlands Antilles, Saba, Bonaire, St Eustatius, Saint Helena, Ascension Island, Tristan da Cunha, Gough Island, Falkland Islands, Macquarie Island, Lord Howe Island, Norfolk Island, Heard Island, McDonald Islands, Diego Garcia, Chagos Archipelago, Cocos Islands, Christmas Island, Kerguelen Islands, Marion Island, Prince Edward Islands, Crozet Islands, Wallis & Futuna, Pitcairn Islands, Cook Islands, Niue Island, Tokelau Islands, American Samoa, Tonga, Tuvalu, Kiribati, Marshall Islands, Micronesia, Federated States Of, Palau, Nauru, Vanuatu, Solomon Islands, Fiji Islands, Samoa Islands, Guam, Northern Mariana Islands, Marianas Islands, Caroline Islands, Palmyra Atoll, Midway Islands, Wake Island, Johnston Atoll, Kingman Reef, Line Islands, Palmyra Atolls, Yap, Pohnpei, Kosrae, Chuuk, Truk, Ponape, Rapa Nui, Easter Island, Society Islands, Cook Islands, Rotuma, Fijian Islands, Wallis & Fatutaka, Tonga, Tuamotus, Marquesas Islands, Tahiti, Austral Islands, New Caledonia, Loyalty Islands, New Hebrides, Pitcairn, Phoenix Islands, Cook Islands, Rarotonga, Tokelau, Tuvalu, Wallis & Futana, Samoan Islands, Nuku Hiva, Tahuata, Raoul Island, Aitutaki, Manihiki, Maupiti, Mitiaro, Mangareva, Gambier Islands, Funafuti, Ellice Islands, Duke of York Island, Kiritimati, Line Islands, Palmerston Island, Bougainville Island, Santa Cruz Islands, New Ireland, Admiralty Islands, Western Isles, Auckland Islands, Campbell Island, Bounty Islands, Henderson Island, Pitcairn Islands.
Diet
Sea dragons are omnivorous. They feed on mysid shrimps, a favorite food, along with other small crustaceans and plankton, and larvafishes. They swallow their prey whole by expanding a joint on their lower snouts. Their diet consists mostly of small organisms such as zooplankton, larvae, and juvenile fish. They also consume some larger animals like crabs and prawns.
They are active during daylight hours and rest during the night. They spend most of their lives near the surface of the ocean, where they hunt for food and avoid predators.
Reproduction
Sea dragons are among the most mysterious creatures in the ocean. They live in tropical waters around the world, including Australia, Indonesia, Japan, Madagascar, Mexico, South Africa, Sri Lanka, Thailand, Tonga, Vanuatu and Venezuela. Sea dragons are generally shy and solitary animals, spending much of their lives hidden under rocks and coral reefs.
Male sea dragons are smaller than females and have a distinctive pattern of dark spots on their bodies. Females are larger and have a lighter body coloration. Males are typically darker than females because they spend more time underwater. Their tails are covered in a thick layer of skin called a “brood patch.” This area is used to hold the eggs while the mother is away.
The eggs are fertilized during mating and are usually laid in shallow coastal areas. After hatching, the young hatchlings swim out of the nest and drift along the surface of the ocean. They look similar to tadpoles and are called “sea dragonlets.” When the baby sea dragons reach sexual maturity, they separate from their parents and begin their own life cycle.
Threats to Survival
Sea dragons live in shallow waters around Australia, where they feed on small crustaceans called mysid shrimp. Their population was devastated by overfishing, pollution, disease and climate change. A few hundred remain today, mostly in protected areas. But the number is still too low to sustain them.
The species is now classified as vulnerable, meaning it faces a high risk of extinction in the wild. There are fewer than 3,500 left in the world, according to estimates published in 2016.