Wobbegong

Wobbegongs
Temporal range: Upper Jurassic–Recent
Spotted wobbegong, Orectolobus maculatus,
showing the camouflage pattern and skin flaps
typical of wobbegongs.
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Chondrichthyes
Subclass: Elasmobranchii
Order: Orectolobiformes
Family: Orectolobidae
T. N. Gill, 1896
Genera

Eucrossorhinus
Orectolobus
Sutorectus

Wobbegong is the common name given to the 12 species of carpet sharks in the family Orectolobidae. They are found in shallow temperate and tropical waters of the western Pacific Ocean and eastern Indian Ocean, chiefly around Australia and Indonesia, although one species (the Japanese wobbegong, Orectolobus japonicus) occurs as far north as Japan. The word wobbegong is believed to come from an Australian Aboriginal language, meaning "shaggy beard", referring to the growths around the mouth of the shark of the western Pacific.

Contents

Description

Wobbegongs are bottom-dwelling sharks and spend much of their time resting on the sea floor. Most species have a maximum length of 1.25 metres (4.1 ft) or less, but the largest, the spotted wobbegong, Orectolobus maculatus, and banded wobbegong, O. halei, reach about 3 metres (9.8 ft) in length.

Wobbegongs are well camouflaged with a symmetrical pattern of bold markings which resembles a carpet. Because of this striking pattern, wobbegongs and their close relatives are often referred to as carpet sharks. The camouflage is improved by the presence of small weed like whiskers lobes[1] surrounding the wobbegong's jaw, which it uses to entice and catch fish. Wobbegongs make use of their relative invisibility to hide among rocks and catch smaller fish which swim too close, typical of ambush predators.

Wobbegongs are generally not dangerous unless they are provoked. They have bitten people who accidentally step on them in shallow water; they may also bite scuba divers or snorkellers who poke or touch them, or who block their escape route. Wobbegongs are very flexible and can easily bite a hand that is holding on to their tail.[2]

They have many small but sharp teeth and their bite can be severe, even through a wetsuit; having once bitten, they have been known to hang on and can be very difficult to remove.[3] To avoid being bitten, divers should avoid contact.

Interaction with humans

Although wobbegongs do not eat humans, humans frequently eat wobbegongs; the flesh of a wobbegong or other shark is called flake and it is often used in fish and chips in Australia.

Wobbegong skin is also used to make leather.

Captivity

Although most wobbegong species are unsuitable for home aquaria due to their large adult size, this has not stopped some of these larger species from being commonly sold in the aquarium trade.[4] However some aquarists have had success in keeping smaller species, such as the tasselled wobbegong and Ward's wobbegong.[4] Small wobbegong species are "ideal" sharks for home aquarists to keep because they are the appropriate size and are sufficiently lethargic in lifestyle, enabling them to be accommodated within the limited space of home aquaria.[4] Some aquarists, by contrast, see the lack of activity to be a drawback to keeping wobbegongs and prefer more active sharks.[4] Wobbegongs are largely nocturnal and will consume tankmates, even rather large ones.[4] Due to their low metabolisms, wobbegong species are not fed as often as other sharks and most do well on two feedings weekly. Underfed wobbegongs can be recognized by visually atrophied dorsal musculature. Wobbegongs can camouflage in waters near rocks.[4]

Genera and species

There are twelve species of wobbegong, in three genera:[5]

Family Orectolobidae

See also

References

  1. ^ "Wobbegongs - five species encountered in Queensland". Queensland Primary Industries and Fisheries. 2009-03-02. http://www.dpi.qld.gov.au/cps/rde/dpi/hs.xsl/28_12484_ENA_HTML.htm. Retrieved 2009-06-14. 
  2. ^ Kuiter, Rudie (1999). Guide to Sea Fishes of Australia (amended ed.). New Holland Publishers (Aust.) Pty Ltd. p. 12. ISBN 1864360917. 
  3. ^ "Shark sinks its teeth in for the long haul". The Sydney Morning Herald. 2004-02-12. http://www.smh.com.au/articles/2004/02/11/1076388440368.html. Retrieved 2006-06-14. 
  4. ^ a b c d e f Michael, Scott W. (March 2004). "Sharks at Home". Aquarium Fish Magazine: pp. 20–29. 
  5. ^ Froese, Rainer, and Daniel Pauly, eds. (2009). "Orectolobidae" in FishBase. January 2009 version.
  6. ^ Huveneers (2006). "Redescription of two species of wobbegongs (Chondrichthyes: Orectolobidae) with elevation of Orectolobus halei Whitley 1940 to species level". Zootaxa 1284: 29–51. http://www.mapress.com/zootaxa/2006f/z01284p051f.pdf. 
  7. ^ Last, Chidlow & Compagno (2006). "A new wobbegong shark, Orectolobus hutchinsi n. sp. (Orectolobiformes: Orectolobidae) from southwestern Australia". Zootaxa 1239: 35–48. http://www.mapress.com/zootaxa/2006f/z01239p048f.pdf.