The next time you step into an aquarium or go scuba diving deep in the seas of Australia, don't miss these graceful sea creatures!
A Leafy Sea Dragon
Native to the seas of South and East Australia, the gentle Leafy Sea Dragon is actually a type of seahorse that lives amongst large floating rafts of seaweed. The leafy sea dragons (Phycodurus eques), is one of the most remarkable examples of camouflage in the animal kingdom. Its mimicry of floating vegetation is remarkable and enables it to forage for food with little chance of being eaten itself.
Mimicry is the ability to blend in to ones surroundings or to look similar to another organism.
The name of the Leafy sea Dragon comes from their appearance, with long leaf-like protrusion all over the body. These leaf-like protrusions are not used for propulsion; they serve only as camouflage. The leafy sea dragon propels itself by its 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 swaying seaweed and kelp.
Catch a video of leafy sea dragons in the deep seas of Australia!
No wonder they belong to the same family...
The Leafy Sea Dragon belongs to the family species Syngnathidae, along with the seahorse. It is a cousin of the pipefish and a cryptic relative of the weedy sea dragon.
A Weedy Sea Dragon
The seahorse is also a master of mimicry and camouflage. It is able to change its colour rapidly in order to blend into their surroundings and evade predation. Another defense mechanism used is mimicry in which some seahorses have adapted appendages that allow them to hide among algae and corals.
Like the sea horses, male leafy sea dragons are responsible for child bearing. However, instead of a pouch like that of the sea horses, male sea dragons have a spongy brood patch on the underside of the tail where females deposit their bright-pink eggs during mating. The eggs are fertilized during the transfer from the female to the male. The males incubate the eggs and carry them to term, releasing miniature sea dragons into the water after about four to six weeks.
Watch a video of a seahorse giving birth!
Mimicry in other species of animals ...
In fact, mimicry is a very common "trick" used by many other species of animals like the Alcon Blue butterfly larvae for example. The study by David Nash and colleagues from Centre for Social Evolution (CSE) at the University of Copenhagen, Denmark, showed that the Alcon Blue Butterfly larvae mimic the surface chemicals that the ants have on their own brood. The closer the mimicry, the faster they get picked up by ants and taken back to the ant nest and put amongst their own brood.
These larvae are parasites and can be highly destructive. Once they successfully tricked the ants into bringing them back to the ant nests, they eat some of the ant brood and will also be fed by the worker ants. They are also fed in preference of the ants' own brood.
After thoughts...
Mimicry and camouflaging of animals is an interesting aspect of animal behaviour. I’m constantly amazed by the animals’ art of mimicry and camouflaging. Animals' mimicry and camouflaging is to avoid danger and ensure continuous supply of food. In the case of the Alcon Blue Butterfly larvae, its parasitic and mimicry behaviour guaranteed the continuos offspring of the Alcon Blue Butterfly. (Poor ants...)
The Leafy Sea Dragon art of mimicry and camouflaging is essential to ensure its survival in its environment. However, they are constantly threatened by human and nature. Many divers like to keep them as pets. Their soft and unstable body caused them to be easily tossed around in huge storms. These factors have caused their numbers to shrink in recent years.
Hence, the next time you are diving in the sea, keep an eye for these creatures as you may have swam past them without noticing! But, just admire them and don't bring them home yah!
References
http://library.thinkquest.org/12880/seahorse.html
http://seahorse.fisheries.ubc.ca/faq.html
http://biology.kenyon.edu/stures/Compsnelson/seafacts.htm
http://www.bbc.co.uk/nature/programmes/tv/wilddownunder/virtual11.shtml
http://members.cox.net/sandymccaw/Musica_Dolce/leafy%20dragon.htm
http://animals.nationalgeographic.com/animals/fish/sea-dragon.html
www.arkive.org/species/GES/fish/Phycodurus_eques
http://www.divegallery.com/Leafy_Sea_Dragon.htm
http://en.wikipedia.org/wiki/Syngnathidae
http://www.amonline.net.au/fishes/students/focus/seadrag.htm
http://www.divegallery.com/Weedy_Sea_Dragon.htm
http://news.bbc.co.uk/1/hi/sci/tech/7171196.stm
http://youtube.com/watch?v=BPlnqckOPdY
http://youtube.com/watch?v=rku0t40SJqY