Ornate wobbegong (Orectolobus ornatus)

Description

Ornate wobbegong fact file

• Description
• Biology
• Range
• Habitat
• Status
• Threats
• Conservation
• Find out more
• Glossary
• References
• Print factsheet

Ornate wobbegong description

With beautifully elaborate colouration, flattened bodies and branched projections around the jaws, wobbegongs are among the most unusual and highly distinctive shark species ^{(3) (4)}. The ornate wobbegong’s particular colouration pattern features broad, dark patches on the upperparts, with black, wavy borders, containing numerous light spots within. These patches are interspersed by lighter areas, also mottled with a multitude of dark spots with light centres ⁽⁵⁾. Overall, the upperparts are golden-brown, and the underparts are pale ⁽³⁾. The arrangement and shape of the fins of wobbegongs is uncharacteristic of sharks, with two dorsal fins set well back on the body, with the first dorsal fin located over the pelvic fins ⁽⁵⁾. The tail is long, with the anal fin set so far back that it appears to be the lower lobe of the caudal fin, which, in fact, only has an upper lobe ^{(3) (6)}. The broad flattened head has two fleshy barbells hanging down from the snout, while on either side of the mouth there are several extra, slightly branched projections, known as dermal lobes, which resemble fronds of seaweed ^{(3) (5)}. The large jaws contain two rows of long, fang-like teeth in the upper jaw and three in the lower jaw ⁽⁵⁾.

Also known as

carpet shark, dwarf ornate wobbegong.

Synonyms

Crossorhinus ornatus, Orectolobus devisi.

Size

Length: 87.5 centimetres ⁽²⁾

Ornate wobbegong biology

A nocturnal, bottom-dwelling species, the ornate wobbegong rests during the day, in caves, under ledges formed by coral reefs, and in trenches ^{(1) (5)}. At nightfall, this species commences hunting for its preferred prey of fish and marine invertebrates, such as octopi and cuttlefish ^{(3) (8)}. The striking colouration of the body provides excellent camouflage amongst fronds of algae and coral, and enables this shark to employ a sit-and-wait ambush strategy. The barbels around the mouth are used as lures to attract prey, which when in range, is quickly snapped in the powerful jaws. While smaller prey is immediately swallowed whole, larger animals may be held in the jaws, sometimes for days, impaled on the fang-like teeth. Once dead, the prey can then be swallowed without a struggle ⁽³⁾.

The ornate wobbegong is an ovoviviparous species, which means that it produces eggs that develop and hatch internally, and therefore gives birth to live young. While inside the uterus, the embryos are initially nourished by the egg yolk sac, but once hatched receive additional nourishment from a nutrient-rich fluid produced by the lining of the mother’s uterus ⁽³⁾. After a gestation period of 10 to 11 months as many as 18, but usually between seven and ten, pups are born, each measuring around 20 cm in length ⁽⁷⁾. The young sharks reach sexual maturity at around 80 centimetres in length. ⁽²⁾.

Ornate wobbegong range

The ornate wobbegong is found in the western Pacific, around the coast of Australia ⁽³⁾. The most recent evidence has led to the ornate wobbegong being split into two distinct species. A smaller form, which retains the original name, ornate wobbegong (Orectolobus ornatus), and a much larger form described as the banded or gulf wobbegong (Orectolobus halei) ^{(2) (7)}. The ornate wobbegong therefore occupies a much smaller distribution than previously thought, ranging from Port Douglas in North Queensland, south to Sydney ⁽⁷⁾. This species has also been reported to occur around Papua New Guinea, Indonesia and Japan, but these record have yet to be substantiated ^{(1) (5)}.

Ornate wobbegong habitat

The ornate wobbegong inhabits tropical inshore regions around coastlines and offshore islands, where it occupies alga-covered rocky bottoms and reef areas ⁽⁵⁾. It can be found from shallow surface waters to depths of 100 metres ^{(1) (5)}.

Ornate wobbegong status

Classified as Near Threatened (NT) on the IUCN Red List ⁽¹⁾.

Ornate wobbegong threats

The main threat to the ornate wobbegong is fishing, both as a result of being directly targeted and through being caught accidentally as bycatch. Although not previously considered to be of commercial value, the flesh is now highly regarded as a food, and the skin is sometimes used to make decorative leather. The most severe effects of fishing have occurred in populations around the east coast of New South Wales in south-east Australia, where combined historic catch data for both the ornate wobbegong and the spotted wobbegong, Orectolobus maculates, indicate a decline of over 60 percent between 1990 and 2000. Elsewhere, catch levels appear to low and stable, but will require monitoring to ensure that they do not become problematic. Like other sharks, the ornate wobbegong takes a relatively long time to reach sexual maturity and produces few offspring, hence it is vulnerable to overexploitation ⁽¹⁾.

Ornate wobbegong conservation

In order to manage wobbegong fishing in New South Wales, legislation has recently been implemented. The Ocean Trap and Line Fishery and the Lobster Fishery are now only permitted to take six individuals of ornate wobbegong per trip, which must each measure at least 180 centimetres in total length ⁽⁹⁾. Recreational fishers are also no longer permitted to retain wobbegong shark catches ⁽⁷⁾. Such measures should help to maintain the population by ensuring that juvenile sharks reach breeding age. Elsewhere, this species can be found in a number of marine protected areas, and therefore its survival looks optimistic ⁽¹⁾.

View information on this species at the UNEP World Conservation Monitoring Centre.

Find out more

To learn more about the conservation of sharks and rays visit:

• Save Our Seas Foundation:
  www.saveourseas.com
• IUCN Shark Specialist Group:
  www.iucnssg.org
• Shark Research Institute:
  www.sharks.org
• Shark Trust:
  www.sharktrust.org

Authentication

Glossary

Anal fin

In fish, an unpaired fin on the under surface of a fish, behind the anus.

Bycatch

In the fishing industry, the part of the catch made up of non-target species.

Caudal fin

The tail fin of a fish.

Dorsal fin

Referring to the fins found on the back of the body of fish, or the raised structure on the back of most cetaceans.

Invertebrates

Animals with no backbone.

Pelvic fins

In fish, the pair of fins found on the underside of the body.

References

1. IUCN Red List (June, 2009)
   http://www.iucnredlist.org
2. Corrigan, S., Huveneers, C. and Schwartz, S. (2008) Genetic and reproductive evidence for two species of ornate wobbegong shark Orectolobus spp. on the Australian east coast. Journal of Fish Biology, 73: 1662 - 1675.
3. Florida Museum of Natural History (July, 2009)
   http://www.flmnh.ufl.edu/fish/Gallery/Descript/OrnateWobbegong/OrnateWobbegong.html
4. Bannister, K. (1993) The Book of the Shark. New Burlington Books, London.
5. Compagno, L.J.V. (2001) Sharks of the world: an annotated and illustrated catalogue of shark species known to date. Food and Agriculture Organization of the United Nations, Rome.
6. Australian Museum (July, 2009)
   http://australianmuseum.net.au/Banded-Wobbegong-Orectolobus-ornatus-De-Vis-1883
7. NSWDPI. (2007) Status of Fisheries Resources in NSW, 2006/2007: Wobbegong Sharks. New South Wales Department of Primary Industries, New South Wales. Available at:
   http://www.dpi.nsw.gov.au/research/areas/systems-research/wild-fisheries/outputs/2008/972/status_short/Wobbegong-Sharks.pdf
8. Huveneers, C., Otway, N.M., Gibbs, S.E. and Harcourt, R.G. (2007) Quantitative diet assessment of wobbegong sharks (genus Orectolobus) in New South Wales, Australia. ICES Journal of Marine Science, 64: 1272 - 1281.
9. Macdonald, I. (2008) Commercial fishing catch limit for wobbegong sharks. New South Wales Government Gazette, 56: 3985 - .