Bluegray carpetshark
Encyclopedia
The bluegrey carpetshark or Colclough's shark (Heteroscyllium colcloughi) is an uncommon species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 of carpet shark
Carpet shark
The carpet sharks are an order, Orectolobiformes, of sharks, so called because many members have ornate patterns reminiscent of carpets....

 endemic to shallow inshore waters off northeastern Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

. It is one of the two extant members of the family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

 Brachaeluridae
Brachaeluridae
The Brachaeluridae, or blind sharks, are a small family of sharks in the order Orectolobiformes. There are only two species of blind shark, both of which are native to shallow coastal waters up to depth, off the eastern coast of Australia....

, and the only member of its genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

. The bluegrey carpetshark has a stocky body with a wide, slightly flattened head, dorsally placed eyes, and a pair of long barbels with posterior skin flaps. It has large pectoral fins, two dorsal fin
Dorsal fin
A dorsal fin is a fin located on the backs of various unrelated marine and freshwater vertebrates, including most fishes, marine mammals , and the ichthyosaurs...

s of unequal size placed far back on the body, and a sizable space between the anal fin and the base of the caudal fin. Growing to 76 cm (29.9 in) long, this species has a black-and-white color pattern as a juvenile, which largely fades with age such as that adults are brownish.

When removed from the water, the bluegrey carpetshark will close its eyes like the related blind shark
Blind shark
The blind shark is one of two species of carpet sharks in the family Brachaeluridae, along with the bluegrey carpetshark , and the only extant member of its genus. Found along the coast of eastern Australia, this nocturnal, bottom-dwelling species is common in rocky areas and seagrass beds from...

 (Brachaelurus waddi). It feeds on benthic invertebrate
Invertebrate
An invertebrate is an animal without a backbone. The group includes 97% of all animal species – all animals except those in the chordate subphylum Vertebrata .Invertebrates form a paraphyletic group...

s and bony fishes, and is aplacental viviparous with females bearing litters of 6–7 pups. The International Union for Conservation of Nature (IUCN) has assessed this species as Vulnerable
Vulnerable species
On 30 January 2010, the IUCN Red List of Threatened Species identified 9694 Vulnerable species, subspecies and varieties, stocks and sub-populations.-References:...

, given its rarity and restricted occurrence in heavily utilized waters. It is taken in small numbers by commercial
Commercial fishing
Commercial fishing is the activity of catching fish and other seafood for commercial profit, mostly from wild fisheries. It provides a large quantity of food to many countries around the world, but those who practice it as an industry must often pursue fish far into the ocean under adverse conditions...

 and recreational fisheries
Recreational fishing
Recreational fishing, also called sport fishing, is fishing for pleasure or competition. It can be contrasted with commercial fishing, which is fishing for profit, or subsistence fishing, which is fishing for survival....

, and for the aquarium trade
Fishkeeping
Fishkeeping is a popular hobby concerned with keeping fish in a home aquarium or garden pond. There is also a fishkeeping industry, as a branch of agriculture.-Types of fishkeeping systems:...

.

Taxonomy

The bluegrey carpetshark was described by Australian ichthyologist James Douglas Ogilby
James Douglas Ogilby
James Douglas Ogilby was an Australian ichthyologist.Ogilby was born in Belfast, Ireland, and was the son of zoologist William Ogilby. He received his education at Winchester College, England, and Trinity College, Dublin.Ogilby worked for the British Museum before joining the Australian Museum in...

 as a species of Brachaelurus, in an 1908 issue of Proceedings of the Royal Society of Queensland. He named the shark after his friend John Colclough, and based his account on two immature males about 46 cm (18.1 in) long from Moreton Bay
Moreton Bay
Moreton Bay is a bay on the eastern coast of Australia 45 km from Brisbane, Queensland. It is one of Queensland's most important coastal resources...

 in Queensland
Queensland
Queensland is a state of Australia, occupying the north-eastern section of the mainland continent. It is bordered by the Northern Territory, South Australia and New South Wales to the west, south-west and south respectively. To the east, Queensland is bordered by the Coral Sea and Pacific Ocean...

, one of which was later "accidentally destroyed". A year after Ogilby's publication, Charles Tate Regan created the new genus Heteroscyllium for this species.

In 1940, Gilbert Percy Whitley
Gilbert Percy Whitley
Gilbert Percy Whitley was a British-born Australian ichthyologist and malacologist who was Curator of Fishes at the Australian Museum in Sydney for about 40 years. He was born at Swaythling, Southampton, England, and was educated at King Edward VI School, Southampton and Osborne House...

 published the first illustrations of the bluegrey carpetshark, but unfortunately they were inaccurate in some respects, particularly on omitting a midline groove on the chin. Much taxonomic confusion then resulted, on whether the bluegrey carpetshark and the blind shark belonged to separate genera or even constituted separate species, that were not resolved until the Queensland Museum
Queensland Museum
The Queensland Museum is the state museum of Queensland. The museum currently operates four separate campuses; at South Brisbane, Ipswich, Toowoomba and Townsville.The museum is funded by the State Government of Queensland.-History:...

 obtained new specimens for study. Other common names for this species include blue-grey catshark, bluegrey shark, and southern blind shark.

Distribution and habitat

Rare to uncommon, the bluegrey carpetshark occurs along the northeastern coast of Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

 from Gladstone, Queensland
Gladstone, Queensland
- Education :Gladstone has several primary schools, three high schools, and one university campus, Central Queensland University. It is also home to CQIT Gladstone Campus.- Recreation :...

 to Ballina, New South Wales
Ballina, New South Wales
Ballina is a town on the Northern Rivers of New South Wales, Australia, and the seat of the Ballina Shire Local Government Area. It had a population of 16,477 in the 2006 Census.-Location:...

, with most records coming from Moreton Bay
Moreton Bay
Moreton Bay is a bay on the eastern coast of Australia 45 km from Brisbane, Queensland. It is one of Queensland's most important coastal resources...

. There are also a handful of reports from off the Cape York Peninsula
Cape York Peninsula
Cape York Peninsula is a large remote peninsula located in Far North Queensland at the tip of the state of Queensland, Australia, the largest unspoilt wilderness in northern Australia and one of the last remaining wilderness areas on Earth...

, and this species may be more widely distributed on the Great Barrier Reef
Great Barrier Reef
The Great Barrier Reef is the world'slargest reef system composed of over 2,900 individual reefs and 900 islands stretching for over 2,600 kilometres over an area of approximately...

. Demersal in nature, the bluegrey carpet shark is usually found close to shore in water less than 6 m (236.2 in) deep, though it has been recorded as far down as 100 m (328.1 ft). It inhabits soft-bottomed habitats and has also been reported around shipwreck
Shipwreck
A shipwreck is what remains of a ship that has wrecked, either sunk or beached. Whatever the cause, a sunken ship or a wrecked ship is a physical example of the event: this explains why the two concepts are often overlapping in English....

s.

Description

The bluegrey carpetshark has a stout body with a long, slightly flattened head. The snout is blunt and looks wedge-shaped from the side. The large eyes are horizontally oval and placed high on the head, each with a strong ridge underneath and a large, round spiracle
Spiracle
Spiracles are openings on the surface of some animals that usually lead to respiratory systems.-Vertebrates:The spiracle is a small hole behind each eye that opens to the mouth in some fishes. In the primitive jawless fish the first gill opening immediately behind the mouth is essentially similar...

s following immediately behind and below. The nostril
Nostril
A nostril is one of the two channels of the nose, from the point where they bifurcate to the external opening. In birds and mammals, they contain branched bones or cartilages called turbinates, whose function is to warm air on inhalation and remove moisture on exhalation...

s are preceded by a pair of long barbels, which have an enlarged posterior flap halfway along their lengths. There are well-developed skin flaps and grooves around the incurrent nostril opening, as well as a pair of grooves connecting them to the small, almost transverse mouth. The tooth rows number 32–34 in the upper jaw and 21–29 in the lower jaw; each tooth has an upright, awl-like central cusp and two lateral cusplets. The five pairs of gill slit
Gill slit
Gill slits are individual openings to gills, i.e., multiple gill arches, which lack a single outer cover. Such gills are characteristic of Cartilaginous fish such as sharks, rays, sawfish, and guitarfish. Most of these have five pairs, but a few species have 6 or 7 pairs...

s are short, with the fourth and fifth pairs more closely spaced than the others.

The pectoral and pelvic fins are broad and rounded, with the former larger than the latter. The two dorsal fin
Dorsal fin
A dorsal fin is a fin located on the backs of various unrelated marine and freshwater vertebrates, including most fishes, marine mammals , and the ichthyosaurs...

 have rounded apices and are placed far back, with the first originating over the pelvic fin bases. The second dorsal fin is noticeably smaller than the first. The anal fin is less than half the size of the first dorsal fin and placed so that its free rear tip just reaches the base of the caudal fin. The caudal fin is long and low and comprises about a quarter of the total length, with no lower lobe and a strong ventral notch near the tip of the upper lobe. The dermal denticles are tiny, smooth, and non-overlapping. Adults are grayish to golden brown above and white below, with faint darker saddles and white patches on the dorsal fins. Juveniles have a striking pattern of large black markings on a white background. This species can grow up to 76 cm (29.9 in) long.

Biology and ecology

Like the blind shark, the bluegrey carpetshark shuts its lower eyelid
Eyelid
An eyelid is a thin fold of skin that covers and protects an eye. With the exception of the prepuce and the labia minora, it has the thinnest skin of the whole body. The levator palpebrae superioris muscle retracts the eyelid to "open" the eye. This can be either voluntarily or involuntarily...

s when taken out of the water. It feeds on small benthic invertebrate
Invertebrate
An invertebrate is an animal without a backbone. The group includes 97% of all animal species – all animals except those in the chordate subphylum Vertebrata .Invertebrates form a paraphyletic group...

s and bony fishes. This species is aplacental viviparous, with the unborn young losing their egg cases early in development and being sustained by yolk sac
Yolk sac
The yolk sac is a membranous sac attached to an embryo, providing early nourishment in the form of yolk in bony fishes, sharks, reptiles, birds, and primitive mammals...

s. Females bear litters of 6–7 young; the newborns measure around 17–18 cm (6.7–7.1 in) long.

Human interactions

Harmless to humans, the bluegrey carpetshark is occasionally captured incidentally
Bycatch
The term “bycatch” is usually used for fish caught unintentionally in a fishery while intending to catch other fish. It may however also indicate untargeted catch in other forms of animal harvesting or collecting...

 by commercial fisheries
Commercial fishing
Commercial fishing is the activity of catching fish and other seafood for commercial profit, mostly from wild fisheries. It provides a large quantity of food to many countries around the world, but those who practice it as an industry must often pursue fish far into the ocean under adverse conditions...

 or hooked by recreational anglers
Recreational fishing
Recreational fishing, also called sport fishing, is fishing for pleasure or competition. It can be contrasted with commercial fishing, which is fishing for profit, or subsistence fishing, which is fishing for survival....

. Small numbers are collected for the private aquarium trade
Fishkeeping
Fishkeeping is a popular hobby concerned with keeping fish in a home aquarium or garden pond. There is also a fishkeeping industry, as a branch of agriculture.-Types of fishkeeping systems:...

, as it is attractive (especially young sharks) and probably adapts well to captivity. The International Union for Conservation of Nature has assessed this species as Vulnerable
Vulnerable species
On 30 January 2010, the IUCN Red List of Threatened Species identified 9694 Vulnerable species, subspecies and varieties, stocks and sub-populations.-References:...

, citing its narrow habitat preferences, limited range in a heavily populated region, and apparent rarity.
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