Blind shark (Brachaelurus waddi)
| Also known as: | brown catfish |
|---|
| Kingdom | Animalia |
|---|---|
| Phylum | Chordata |
| Class | Chondrichthyes |
| Order | Orectolobiformes |
| Family | Brachaeluridae |
| Genus | Brachaelurus (1) |
| Size | Length: usually less than 120 cm (2) |
Classified as Least Concern (LC) on the IUCN Red List (1).
This small, stout shark gets its name from its habit of retracting its eyeballs, which causes its thick eyelids to close, when removed from water. It is usually brown above with white spots, and sometimes has darker saddle stripes. Underneath, the shark is light yellowish with many small, white spots. It has a relatively short tail region, and two equal-sized dorsal fins are located far back on the body. Large, conspicuous spiracles (respiratory openings) are located just behind the small eyes, and distinctive barbels (long, fleshy projections) hang down next to the tiny mouth (2) (3).
Occurs in the western South Pacific, along the east coast of Australia (3).
The blind shark inhabits rocky shorelines, coral reefs and seagrass beds. It can be found close inshore in tidepools, down to depths of 140 metres (2).
The blind shark is a sluggish, nocturnal shark that hides in caves and under ledges during the day, and comes out at night to feed (2). Its diet is composed of small fishes, crabs, shrimps, cuttlefish, squid and sea anemones (2) (3). Blind sharks are viviparous, but there no placenta is formed (4). Seven to eight pups are produced in each litter, which are born in the summer, around November (3). It is thought that blind sharks produce a litter each year (5).
This relatively common shark is not targeted by commercial fisheries due to its apparently unpalatable flesh (5). It is however caught by sports fisherman, though it is thought that most are returned to the water and that this recreational activity has very little impact on the shark (1) (5). The blind shark is likely to be caught unintentionally as by-catch in trawl fisheries; however, it is known to be able to survive for up to 18 hours out of water, and thus may survive trawl capture if released back into the ocean. They are also exploited for the marine aquarium trade, and are reported to be a hardy species that can thrive in such environments (5).
A number of MPAs and aquatic reserves occur within the range of the blind shark; however, fishing activities are permitted in many of them (5). Although the blind shark is not considered to be at risk of extinction at present, research into this species’ biology and ecology would provide more information on the status of the species, and further research into what extent the blind shark may be affected by by-catch is also required (1).
For further information on sharks and their conservation see:
Save Our Seas Foundation:
http://www.saveourseas.com/
Project Aware:
www.projectaware.org
For further information on the blind shark see:
FAO Species Catalogue, Volume 4: Sharks of the World:
http://www.fao.org/docrep/009/ad122e/ad122e00.htm
Authenticated (13/08/07) by John Stevens, Senior Principal Research Scientist, CSIRO Marine and Atmospheric Research.
- By-catch: in the fishing industry, the part of the catch made up of non-target species.
- Dorsal fins: the unpaired fins found on the back of the body of fish, or the raised structure on the back of most cetaceans.
- Nocturnal: active at night.
- Placenta: in animals, a temporary organ present in females during pregnancy. The placenta is the primary site of nutrition and gas exchange between the mother and the embryo.
- Viviparous: giving birth to live offspring that develop inside the mother’s body.
-
IUCN Red List (June, 2007)
http://www.iucnredlist.org - Compagno, L.J.V., Fowler, S. and Dando, M. (2005) Sharks of the World. Harper Collins, London.
- Compagno, L.J.V. (1984) FAO Species Catalogue. Vol 4: Sharks of the World. An annotated and illustrated catalogue of shark species known to date. Part 1: Hexanchiformes to Lamniformes. Food and Agricultural Organization of the United Nations, Rome.
- Stevens, J.D. (2007) Pers. comm.
- Cavanagh, R.D., Kyne, P.M., Fowler, S.L., Musick, J.A. and Bennett, M.B. (2003) The Conservation Status of Australian Chondrichthyans: Report of the IUCN Shark Specialist Group Australia and Oceania Regional Red List Workshop. The University of Queensland, School of Biomedical Sciences, Brisbane, Australia.