| Carpet sharks | |
|---|---|
 | |
| Spotted wobbegong (Orectolobus maculatus) | |
Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Chondrichthyes |
| Subclass: | Elasmobranchii |
| Division: | Selachii |
| Superorder: | Galeomorphi |
| Order: | Orectolobiformes Applegate, 1972 |
| Families | |
Seetext | |
Carpet sharks aresharks classified in theorderOrectolobiformes/ɒrɛkˈtɒləbɪfɔːrmiːz/. Sometimes thecommon name "carpet shark" (given because many species resemble ornately patternedcarpets) is used interchangeably with "wobbegong", which is the common name of sharks in the familyOrectolobidae. Carpet sharks have fivegill slits, two spinelessdorsal fins, and a small mouth that does not extend past the eyes. Many species havebarbels.
The carpet sharks are a diverse group of sharks with differing sizes, appearances, diets, and habits. They first appeared in thefossil record in theEarly Jurassic; the oldest known orectolobiform genera areFolipistrix (known fromToarcian toAalenian ofBelgium andGermany),Palaeobrachaelurus (Aalenian toBarremian) andAnnea (Toarcian toBajocian of Europe).[1] All species have two dorsal fins and a relatively short, transverse mouth that does not extend behind the eyes. Besides the nostrils arebarbels, tactile sensory organs, and grooves known as nasoral grooves connect the nostrils to the mouth. Five short gill slits are just in front of the origin of the pectoral fin and the fifth slit tends to overlap the fourth one.[2] Aspiracle occurs beneath each eye which is used in respiration. The only exception to this rule is the whale shark, the spiracles of which are situated just behind the eyes.[3] Carpet sharks derive their common name from the fact that many species have a mottled appearance with intricate patterns reminiscent of carpet designs. The patterning provides camouflage when the fish is lying on the seabed.[4] The largest carpet shark is thewhale shark (Rhincodon typus) which can grow to a length of 14 m (46 ft) to 18.8 metres (62 ft).[5] It is the largest species of fish, but despite its size, is not dangerous, as it is afilter feeder, drawing in water through its wide mouth and sifting out theplankton. The smallest carpet shark, at up to about 30 cm (12 in) long, is thebarbelthroat carpet shark, (Cirrhoscyllium expolitum).[3] Some of the most spectacularly coloured members of the order are thenecklace carpet shark (Parascyllium variolatum), thezebra shark (Stegostoma fasciatum), theEpaulette shark (Hemiscyllium ocellatum), and theornate wobbegong (Orectolobus ornatus). Nurse sharks and whale sharks have a fringe of barbels on their snouts, andbarbelthroat carpet sharks (Cirrhoscyllium expolitum) have barbels dangling from their throat regions.
Most carpet sharks feed on the seabed in shallow to medium-depth waters, detecting and picking up molluscs, crustaceans, and other small creatures.[3] Thewobbegongs tend to beambush predators, lying hidden on the seabed untilprey approaches. One has been observed swallowing abamboo shark whole.[6]
The methods of reproduction of carpet sharks varies. Some species areoviparous and lay eggs which may be liberated directly into the water or may be enclosed inhorny egg cases. Some female sharks have been observed to push egg cases into crevices and this would be an added protection for the developing embryos. Other species areovoviviparous and the fertilised eggs are retained in the mother'soviduct. There, the developing embryos, which are usually few in number, feed on theiryolk sacs at first and later hatch out and feed on nutrients secreted by the walls of the oviduct. The young are born in an advanced state, ready to live independent lives.[3]
Carpet sharks are found in all the oceans of the world but predominantly in tropical and temperate waters. They are most common in the westernIndo-Pacific region and are usually found in relatively deep water.[3]
The order is small, with sevenfamilies in 13genera and with a total of around 43species:
| Family | Image | Common name | Genera | Species | Description |
|---|---|---|---|---|---|
| Brachaeluridae |  | Blind sharks | 1 | 2 | Blind sharks are found in shallow coastal waters up to 110 m (360 ft) deep off the eastern coast ofAustralia.[7] They are distinguished by the presence of longbarbels, largespiracles, and grooves around the nostrils. They have twodorsal fins, placed close together on the back, and a relatively short tail. Blind sharks feed on small fish,cuttlefish,sea anemones, andcrustaceans. The female retains the eggs in her body until they hatch (ovoviviparity), during which time the embryos feed solely on the egg yolk.[7] Despite their name, blind sharks are not blind; their name comes from their habit of closing their eyes when taken out of water.[7] There are only two species. |
| Ginglymostomatidae |  | Nurse sharks | 3 | 4 | Nurse sharks have long tails and distinctive mouths which are far ahead of the eyes and before the snout (subterminal), an indication of the bottom-dwelling (benthic) nature of these sharks. Also present on the lower jaw are two fleshy barbels,chemosensory organs which help the nurse sharks find prey hidden in the sediments. Common in shallow, tropical, and subtropical waters, these sharks are sluggish and docilebottom-dwellers. Nurse sharks typically attack humans only if directly threatened. The largest species can reach a length of 4.3 m (14 ft).[8] |
| Hemiscylliidae |  | Bamboo sharks | 2 extant 4 extinct | 16 extant 6 extinct | Bamboo sharks, sometimes called longtail carpet sharks, are distinguished by a relatively long snout with subterminalnostrils.[9] They are relatively small sharks, with the largest species reaching only 121 cm (48 in) in length. They have elongated, cylindrical bodies, with short barbels and large spiracles. As their common name suggests, they have unusually long tails, exceeding the length of the rest of their bodies. They are found in shallow waters of the tropicalIndo-Pacific. They are sluggish fish, feeding on bottom-dwelling invertebrates and smaller fish.[10] |
| Orectolobidae |  | Wobbegong sharks | 3 extant 1 extinct | 12 extant 1 extinct | Wobbegong sharks are wellcamouflaged with symmetric, bold patterns resembling a carpet. The camouflage is improved by the presence of small weed-like whisker lobes surrounding the jaw, which help to camouflage it and act as sensory barbs.[11] Wobbegongs are bottom-dwelling and spend much time resting on the sea floor. They are found in shallow temperate and tropical waters of the westernPacific Ocean and easternIndian Ocean, chiefly around Australia and Indonesia. Most species have a maximum length of 1.25 m (4.1 ft) or less, and the largest reach about 3 m (9.8 ft) in length. Wobbegongs are generally not dangerous to humans unless provoked.[12] |
| Parascylliidae |  | Collared carpet sharks | 2 | 8 | Collared carpet sharks have elongated, slender bodies, cat-like eyes, and barbels behind their chins. They are found only in the shallow waters of the western Pacific. They are relatively small sharks, with the largest species reaching no more than 91 cm (2.99 ft) in adult length.[13] |
| Rhincodontidae |  | Whale sharks | 1 | 1 | Thewhale shark is the largestextant fishspecies, growing over 12 m (40 ft) long and weighing over 20 tonnes (45,000 lb). It is a slow-moving filter feeder with a very large mouth, feeding mainly, though not exclusively, on plankton. The whale shark is apelagic species, living in the open sea in tropical and warm oceans with a lifespan around 70 years.[14] TheIUCN has assessed it asEndangered.[15] |
| Stegostomatidae |  | Zebra sharks | 1 | 1 | Zebra sharks are distinctive in appearance, with five longitudinal ridges on a cylindrical body, a lowcaudal fin comprising nearly half the total length, and a pattern of dark spots on a pale background. They grow to a length of 2.5 m (8.2 ft), and are found throughout the tropical Indo-Pacific, frequentingcoral reefs and sandy flats to a depth of 62 m (210 ft). They arenocturnal and spend most of the day resting motionless on the sea floor. They are innocuous to humans. The IUCN has assessed them as endangered and their populations are likely in decline.[16] |
Order Orectolobiformes
The following fossil genera are recognized:[23][24]
| International | |
|---|---|
| National | |
| Other | |
