The wobbegong family, known as Orectolobidae, are represented by eight described members and several undescribed species. Limited in their range to the Indo-Pacific region, wobbegongs are found around Papua New Guinea, several South East Asia countries, Japan and e
specially
Australia, where most members of the family reside.Wobbegongs are easily distinguished from other shark species by their flattened bodies, their wonderful camouflaged skin patterns and by their dermal lobes, those shaggy beards found around their heads. These sharks are found in depths from 1m to 200m, inhabit rocky and coral reefs and prefer to shelter in caves and ledges, except for large wobbies that boldly lay out in the open.
The two largest members of the family are the spotted wobbegong (Orectolobus maculatus) and the banded wobbegong (Orectolobus halei), which both reach 3m in length and are the most prolific species encountered in southern Australia. The banded wobbegong has just been described as a separate species, but was previously thought to be the adult form of the ornate wobbegong.
The most common tropical species are the tasselled wobbegong (Eucrossorhinus dasypogon) and ornate wobbegong (Orectolobus ornatus). The tasselled wobbegong is reported to grow to 3m, however sharks over 2m in length are rare. This wobby is the most common species seen on the Great Barrier Reef and Ningaloo Reef, but is also found off Papua New Guinea and Indonesia. The tasselled wobbegong has superb camouflage, and is thought to flick its tail to lure potential prey close to its mouth. The ornate wobbegong only reaches a length of 1m and is found off New South Wales, Queensland, Papua New Guinea and West Papua, and has a preference for lying on plate corals, which makes it a great photo subject.
Another tropical Australian species is the northern wobbegong (Orectolobus wardi). This shark is one of the rarest members of the family, growing to less than a metre long. A highlight of a recent trip to Ningaloo Reef in Western Australia for us was not only swimming with whale sharks, but finding a tiny shy northern wobbegong sheltering under a ledge.
Two other wobbegong speci
es
are found in the cooler waters of south west Australia, the western wobbegong (Orectolobus
hutchinsi) and cobbler wobbegong (Sutorectus
tentaculatus), and recent research seems to indicate that two undescribed
species also exist in this area.The only wobbegong species not found off Australia is the Japanese wobbegong (Orectolobus japonicus), which inhabits reefs off Japan, Vietnam and the Philippines. However, there may be a few other non-Australian species added to this list with three other wobbegongs recently discovered in fish markets in Indonesia and the Philippines.
Wobbegongs appear to be very lazy sharks, just lying around on the bottom all day. However, these sharks are ambush predators, and will grab almost any prey that comes close to their mouth. They use their camouflage skin pattern to blend with the bottom substrate, and feed on fish, octopus, squid, small rays, other sharks and even other wobbegongs. Divers have seen wobbegongs eating Port Jackson sharks and even grey nurse sharks! They have very sharp dagger-like teeth and when they bite they don’t like to let go until their prey is either dead or in the right position to be swallowed whole. At night they are much more active, patrolling the bottom looking for prey.
Numerous scuba divers and spearfishermen have been bitten by wobbegongs in Australia, and quite a few divers have had to exit the water with the wobbegong still attached! Though generally harmless, they will bite if harassed or stimulated by the presence of food, especially speared fish. Divers can usually get very close to wobbies, and they make for great photo subjects. We have photographed thousands and haven’t been bitten, yet, but have had some close calls. They will usually give a warning snap to back off if you encroach too close. Nigel once watched a diver attempt to pat a huge spotted wobbegong, almost 3m long and with a head a metre wide. As the diver reached out the wobby quickly turned and snapped at him, just millimetres from his face. The diver turned white and quickly retreated.
Wobbegong mating, like most sharks, can be quite violent, with the male biting the female near the head and twisting his body around hers so he can insert one of his claspers. Wobbegongs give birth to live young and have litters ranging in number from 9 to 29, depending on the species. Young wobbegong sharks are around 20cm long at birth and are rarely seen, they appear to hide under ledges to avoid getting eaten by larger wobbies!
The best area of Australia to encounter large numbers of wobbegongs is northern New South Wales and southern Queensland. Here three species are regular encountered, the ornate, spotted and banded wobbegongs. At places like Julian Rocks off Byron Bay, the wobbegongs are so numerous that dozens can be seen on a dive, lying on the sand, coral and each other.
Unfortunately, wobbegongs have very tasty flesh, which has led to them being heavily targeted by a number of fisheries in Australia. Since the early 1990s wobbegong numbers in New South Wales have been decimated in many areas, with a commercial drop-lining fishery taking up to 120 tonnes a year. That figure had fallen to 40 tonnes by 2000 due to a decline in wobbegongs, but with little management this fishery is unsustainable. Divers have petitioned the New South Wales state government to control this fishery, with little success.
The name wobbegong comes from an Australian Aboriginal word meaning ‘shaggy beard’, which is a great description of one of the most unique sharks a diver will encounter in the seas around Australia.