Dragons of myth, legend and popular folklore range from Western Europe to the Far East. In most countries, basic dragon anatomy consists of a snake or crocodile, which has fish scales. The feet, wings and/or head are like that of a hawk or eagle. Its forelimbs, and sometimes the head, are of a lion.
With such a combination of unnatural features, some dragon enthusiasts believe that all these mythical creatures are the progeny of the same ultimate ancestors – even if those ancestors are also merely the stuff of legend. One thing is for sure, whether they’re based on fact or fiction, dragons have fascinated humans for centuries.
However, in the waters off southern Australia lives a real sea dragon that is neither sea-horse nor fish as we know them. It has a long, tube-like snout, armour plating and a tail that does not curl like that of a seahorse. It has bizarre weed-like growths on its body and the males give birth to the young. If ever there was a real creature that conformed to the unnatural features of a mythical dragon, this is it – the weedy sea dragon: Phyllopteryx Taeniolatus. Weedy sea dragons are endemic to the waters of southern Australia.
One of the weedy sea dragon’s most bizarre attributes, and one that it does, in fact, share with seahorses, is that it reverses roles when rearing young. The male carries and looks after the eggs. The male carries the fertilized eggs, which are incubated until they hatch – usually in January each year. The eggs are cemented onto the underside of his long tail, where tufts of algae often grow on the surface like they might on the hull of a yacht.
The female lays her eggs under the male’s tail. About 10 rows are laid along its length, covering the lower part of the tail. The eggs are sticky, and a reaction causes the male’s skin to soften and rise half way up along the sides of each egg. When the skin re-hardens, it forms small cups and after the eggs hatch these cups remain evident for a short time.
The number of eggs found on males varies, but an average would be 200 for Victorian specimens and 150 for those found off NSW. The eggs are carried for about two months, until they hatch. The young dragons grow quickly, reaching a size of about 70mm in three weeks. It takes two years for the babies to reach maturity, attaining a length of up to 45cm.
Weedy sea dragons belong to the family Syngnathidae, which includes the most distinctive of fish, like seahorses and pipefish. Weedy sea dragons are more closely related to the latter than the former.
Their bodies lack scales and are encased in a series of bony rings that bear four to nine longitudinal ridges. The snout is long and tube-like, while the jaws lack true teeth and the gill openings are relatively small. In short, the family includes toothless fish with a bony carapace.
PART OF THE FAMILY
Weedy sea dragons are, in fact, fish, although they don’t have the characteristic fish shape and some of the other fish-like structures have been severely modified or abandoned altogether. However, they are cold-blooded, lay eggs and obtain oxygen through their gills.
They do have all the other fish-like physiological structures, such as a two-chambered heart, delicate translucent ray fins and a mucous body covering. The scales of weedy sea dragons have become fused together to form a series of bony plates and arches covering their bodies, making their abdomens quite inflexible. The sacrifice in flexibility serves to make them less edible in the eyes of potential predators. They also have long, straight non-prehensile tails – unlike seahorses, which have curly prehensile tails – for twirling around sponges and seaweed.
They’re true bony fishes and they also have a rudimentary swim bladder. This allows them to adjust their specific gravity to equal that of the surrounding water. As a result, the tendency to sink to the bottom, such as in primitive fishes like sharks, is avoided. Weedy sea dragons can control their buoyancy like other advanced fishes.
They move by making rapid vibrations of delicate, translucent pectoral and dorsal fins. Both of these are coordinated to keep the dragon in a vertical position. Their fins flicker at amazing speeds; in fact, each fin ray can move side to side as quickly as 70 times per second.
This fast vibrating movement both drives and steers sea dragons. It also enables them to manoeuvre into any position and to navigate in and out of tight spaces. This precise method of movement is important when it comes to negotiating the tangled kelp forests where they live.
Weedy sea dragons have tiny fins on either side of their head and a long transparent dorsal fin along their backs. In calm waters, they can steam ahead quite quickly and divers often end up following their tails around kelp beds.
When you watch one gracefully swimming around kelp, you will notice it’s rarely in a hurry and its slow, graceful movements are in perfect harmony with the surroundings.
It was only after my first year of scuba diving that I saw my first weedy sea dragon, as they can be hard to find until the eyes become accustomed to spotting them. They are masters of camouflage and easy to overlook because they look just like a piece of kelp. They have leaf-like appendages decorating their bodies and their orange/olive colour make them look like bits of torn kelp. This form of camouflage is called mimicry, where the creature looks and behaves like a part of the environment it inhabits.
Sadly, this camouflage and habitat can also lead to their downfall, because during big storms they can be washed onto the shore together with the kelp. Large storms can destroy sea dragon habitat and beach-combers often find dragons washed onto beaches as a result.
To find sea dragons in south-eastern Australia, head for areas where kelpy reefs meet the sand, usually at a depth of 15m to 25m. In Victoria, weedy sea dragons are very common on sea grass beds in shallower waters. Generally speaking, you’ll find them in rocky reefs, seaweed beds and around pylons colonised by seaweed, such as in Sydney Harbour.
Weedy sea dragons can be found in depths of 3 to 50m, from Geraldton in WA to Port Stephens in NSW and around Tasmania. Both Sydney Harbour and Botany Bay support their own healthy populations. Scuba diving sites like La Perouse and Captain Cooks Landing at Kurnell, both in Botany Bay, are particularly good places to see sea dragons in their natural environment.
Baby dragons are very difficult to find and it takes a specially-trained eye to spot the tiny creatures. But one of the best places to find them is near the seabed among their food source – schools of tiny, shrimp-like mysids. Sea dragons feed on plankton, larval fish and mysids, which they suck in using their long, tube-like snouts, and they often swim in pairs.
Photographing sea dragons underwater can be tricky, because they will keep swimming away from you. You will almost always end up with photos of their tail ends. The best method, I think, is to slowly follow them and take your shots as they continually negotiate the contours of the kelp forest.
But it’s important not to handle them, as they are very delicate and if their mucous coating is rubbed off, they can easily develop infections. The mucous is believed to act as a barrier against attack from a host of micro-organisms. It also possibly assists with their osmo-regulation, which helps to prevent water/fluid loss.
Weedy sea dragons are a protected species in NSW. They are difficult to keep in aquaria, as their natural diet is difficult to duplicate.
Inshore fish trawling represents a direct threat to weedy sea dragons. They can be dragged to the surface, together with sponges and other fish, causing them to die from air embolisms. Dragons do not have time to adjust the pressure in their swim bladders, so when they are forced to the surface, their bladders expand and tear. Scuba divers should take note that moving them out of their depth poses a serious risk.
Scientists from the University of Technology, in Sydney, have been studying the reproductive cycle and growth of the weedy sea dragon. They found they have well-defined home ranges, but the males move to better sites to look after their eggs and give birth. Some males have more than one brood per season, with about 60 days between broods. Their breeding peaks just before the time of warmest water and with the higher temperature and plenty of food, the young dragons grow quickly in the first few months. Both males and females become sexually mature at 28 months, when they reach about 33cm in length.
These findings indicate that weedy sea dragons have a lower recruitment rate than seahorses and pipefish, so their populations may be more vulnerable to aquarium collecting and habitat destruction. The survival of the young dragons is dependant on their food – mysids – which are very sensitive to pollution.
Another research project is ‘Dragon Search’, which has part-time co-ordinators in each Australian state where the dragons live. The project is supported by organisations such as the Marine and Coastal Community Network, the Threatened Species Network and the Australian Marine Conservation Society. In total, there are nearly 20 organisations directly involved in the project.
‘Dragon Search’ collects data on sea dragon sightings by scuba divers, snorkelers and beach-combers. The ultimate aim of the project is to gather information to identify suitable sites for marine protected areas for sea dragons and, consequently, to create an atmosphere of responsibility and ownership in the community towards these areas.
A number of researchers are now undertaking investigations into sea dragon colonies. Researcher, Jaime Sanchez has tagged over 60 dragons in southern NSW, using an elastomer – a tag that can only be seen under a fluorescent light – which he takes underwater. By tagging them, Jaime hopes to learn a lot about dragon ecology and increase community awareness of this rare marine species.
Weedy sea dragons are very delicate and sensitive things. If we learn to respect these beautiful, vulnerable creatures and preserve their environment, they can provide us and future generations with immeasurable wonder and enjoyment.