Bluegrey carpetshark (Brachaelurus colcloughi)
|Also known as:||bluegray carpetshark, Colclough's shark|
|Size||Length: up to 85 cm (2)|
The bluegrey carpetshark is classified as Vulnerable (VU) on the IUCN Red List (1).
A relatively small and poorly known species, the bluegrey carpetshark (Brachaelurus colcloughi) is a bottom-dwelling shark that is rarely seen (2). It was discovered by James Ogilby in 1908, who named this attractive shark after his friend, Mr. Colclough (3). The bluegrey carpetshark is one of only two species in the family Brachaeluridae, also known as the blind sharks (2).
The juvenile bluegrey carpetshark has a whitish body with conspicuous black markings. These markings slowly fade as it develops into an adult, resulting in a brownish appearance. The adult bluegrey carpetshark has a partially flattened head with two distinctive barbels which hang down either side of its tiny mouth (4).
The bluegrey carpetshark is endemic to the east coast of Australia in the Western Pacific (2). It is found on the continental shelf, mainly off southern Queensland between Gladstone and Coolangatta,and on the Great Barrier Reef (5).
The bluegrey carpetshark is a bottom-dwelling shark, primarily found in shallow, inshore waters, less than five metres deep (1). However, it has also been reported at depths of up to 217 metres (5). The bluegrey carpetshark is often found on seagrass beds with a mud-sand-shell substrate (2).
Very little is known about the biology of the bluegrey carpetshark. It is an ovoviviparous species which produces an average of 6 to 8 pups per litter, each of which measure 17 to 18 centimetres (5).
It is thought that during the day the bluegrey carpetshark takes refuge under ledges and in caves, and then comes out at night to forage around reefs and over seagrass beds (2).
The diet of the bluegrey carpetshark is not widely described. Some studies suggest it feeds primarily on benthic fish and possibly benthic invertebrates (2).
Like other blind sharks, when the bluegrey carpetshark is removed from the water it shuts its lower eyelids, a behaviour which gives blind sharks their name (6).
Prior to 2001, only 20 specimens of the bluegrey carpetshark had been recorded. The rarity, limited reproductive capacity, and restricted geographic range of this species makes it very vulnerable to any threats (2).
The bluegrey carpetshark inhabits waters that are fished intensively and used heavily by humans. Therefore habitat degradation is a major threat and is likely to reduce the already small area in which this shark occurs (5). There are plans for large developments in Moreton Bay, a key site for the bluegrey carpetshark, which are likely to affect nearshore marine habitats. Pollution from marine and land sources are also a potential threat to the species (2).
The bluegrey carpetshark is also caught as bycatch in trawl fisheries. When this occurs, the shark is often sold to the private aquarium trade (1).
There are currently no specific conservation measures in place for the bluegrey carpetshark. However, its numbers are being monitored (5) and areas of its habitat on the Great Barrier Reef and within the Moreton Bay Marine Park are protected (1) (2).
Find out more about the conservation of the bluegrey carpetshark’s habitat:
Moreton Bay Marine Park Monitoring Program:
Learn more about sharks and their conservation:
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- Barbels: fleshy projections near the mouth of some aquatic vertebrates.
- Benthic: relating to the lowermost region of a body of water such as an ocean or lake, or to the organisms that live there.
- Bycatch: the fishing industry, the part of the catch made up of non-target species.
- Endemic: a species or taxonomic group that is only found in one particular country or geographic area.
- Invertebrates: animals with no backbone, such as insects, crustaceans, worms, molluscs, spiders, cnidarians (jellyfish, corals, sea anemones) and echinoderms.
- Ovoviviparous: method of reproduction whereby the egg shell is weakly formed and young hatch inside the female; they are nourished by their yolk sac and then ‘born’ live.
IUCN Red List (July, 2011)
- Kyne, P.M., Compagno, L.J.V., Stead, J., Jackson, M.V. and Bennett, M.B. (2011) Distribution, habitat and biology of a rare and threatened eastern Australian endemic shark: Colclough’s shark, Brachaelurus colcloughi Ogilby, 1908. Marine and Freshwater Research, 62: 540-547.
- Ogilby, J.D. (1908) On new genera and species of fishes. Proceedings of the Royal Society of Queensland, 21: 1-26.
- Last, P.R. and Stevens, J.D. (2009) Sharks and Rays of Australia. Second Edition. Harvard University Press, Cambridge, USA.
- Pogonoski, J.J., Pollard, D.A. and Paxton, J.R. (February, 2002) Conservation Overview and Action Plan for Australian Threatened and Potentially Threatened Marine and Estuarine Fishes. Environment Australia, Australia.
Compagno, L.J.V. (2001) FAO Species Catalogue. Volume 2: Sharks of the World. An Annotated and Illustrated Catalogue of Shark Species Known to Date. Bullhead, Mackerel and Carpet Sharks (Heterodontiformes, Lamniformes andOrectolobiformes). Food and Agriculture Organization of the United Nations, Rome. Available at: