Clubnose guitarfish (Glaucostegus thouin)

Description

What’s the World’s Favourite Species?

Clubnose guitarfish fact file

• Description
• Biology
• Range
• Habitat
• Status
• Threats
• Conservation
• Find out more
• Glossary
• References
• Print factsheet

Clubnose guitarfish description

The characteristic heart-shaped silhouette of the clubnose guitarfish (Glaucostegus thouin) is the result of a somewhat bizarre feature of its development, where the head is fused on each side to enlarged pectoral fins. Named for its elongated, club-like snout, the clubnose guitarfish has a flattened, slender trunk with rounded pelvic fins and two large dorsal fins, while the long, stout tail bears an imposing, shark-like caudal fin ^{(3) (4)}. The body is covered in tiny, tooth-like scales which reduce drag in the water and make swimming more efficient. The clubnose guitarfish is generally brownish in colour, sometimes varying from yellow-brown, grey-brown, greenish or black, and is usually white underneath ^{(4) (5)}.

Synonyms

Rhinobatos thouin.

Size

Length: 2.5 – 3 metres ⁽²⁾

Clubnose guitarfish biology

Relatively little is known about the biology of this species, although it is thought that the clubnose guitarfish feeds on small fish and invertebrates that live on or near the sea bed ⁽¹⁾. Most guitarfish in the Rhinobatidae family are suction feeders, where prey is sucked into the mouth and swallowed whole ^{(4) (5) (6)}. The breeding behaviour of the clubnose guitarfish is not well documented; however, it is likely to be ovoviviparous ^{(5) (6)}.

Clubnose guitarfish range

The clubnose guitarfish is found in inshore waters, spanning from the Red Sea, to Malaysia, Singapore, Thailand, Vietnam, Indonesia, New Guinea and Japan. Unconfirmed reports suggest that the clubnose guitarfish may also inhabit waters in the Mediterranean and Suriname ^{(1) (2) (6)}.

Clubnose guitarfish habitat

A bottom-dwelling (benthic) species, the clubnose guitarfish is typically found over soft and sandy substrate at less than 60 metres depth ⁽¹⁾.

Clubnose guitarfish status

The clubnose guitarfish is classified as Vulnerable (VU) on the IUCN Red List ⁽¹⁾.

Clubnose guitarfish threats

The clubnose guitarfish is threatened by both small scale and commercial fisheries where it may be targeted for its valuable fins, or caught accidentally as bycatch. As so little is known about the biology and habitat requirements of the clubnose guitarfish, it is difficult to assess the impact of other potential threats for this species; however, it is likely that human activities, destructive fishing practices, habitat degradation and pollution will all have an increasingly negative impact on survival ^{(1) (6)}.

Clubnose guitarfish conservation

Much more research is required on the population structure, biology and ecology of the clubnose guitarfish, in order to determine how fishing practices, habitat destruction and other pressures are threatening the species. In addition, management plans must be developed in order to facilitate the conservation and sustainable management of this species ⁽¹⁾. 

View information on this species at the UNEP World Conservation Monitoring Centre.

Environment Agency - Abu Dhabi is a principal sponsor of ARKive. EAD is working to protect and conserve the environment as well as promoting sustainable development in the Emirate of Abu Dhabi.

Find out more

To find out more about the conservation of rays and sharks, see:

• Save Our Seas Foundation:
  http://www.saveourseas.com
• IUCN Shark Specialist Group:
  http://www.iucnssg.org
• Shark Research Institute:
  http://www.sharks.org
• Shark Trust:
  http://www.sharktrust.org

Authentication

This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact:
arkive@wildscreen.org.uk

Glossary

Bycatch

In the fishing industry, the part of the catch made up of non-target species.

Caudal fin

The tail fin of a fish.

Dorsal fin

The unpaired fin found on the back of the body of fish, or the raised structure on the back of most cetaceans.

Invertebrates

Animals with no backbone, such as insects, crustaceans, worms, molluscs, spiders, cnidarians (jellyfish, corals, sea anemones), echinoderms, and others.

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.

Pectoral fins

In fish, the pair of fins that are found one on each side of the body just behind the gills. They are generally used for balancing and braking.

Pelvic fins

In fish, the pair of fins found on the underside of the body.

References

1. IUCN Red List (September, 2010)
   http://www.iucnredlist.org/
2. Bonfil, R. and Abdallah, M. (2004) Field identification guide to the sharks and rays of the Red Sea and Gulf of Aden. Food and Agriculture Organisation of the United Nations, Rome. Available at:
   ftp://ftp.fao.org/docrep/fao/009/y5080e/y5080e00.pdf
3. Campbell, A. and Dawes, J. (2004) Encyclopedia of Underwater Life. Oxford University Press, Oxford.
4. Carpenter, K.E. and Niem, V.H. (1999) The Living Marine Resources of the Western Central Pacific. Volume 3: Batoid Fishes, Chimaeras and Bony Fishes. Part 1 (Elopidae to Linophyrnidae). Food and Agriculture Organisations of the United Nations, Rome. Available at:
   ftp://ftp.fao.org/docrep/fao/009/x2401e/x2401e00.pdf
5. Elasmobranch Research Laboratory, Florida Atlantic University (September, 2010)
   http://www.science.fau.edu/sharklab/courses/elasmobiology/families/Rhinobatidae.pdf
6. Fish Base (September, 2010)
   http://www.fishbase.org/Summary/SpeciesSummary.php?id=12578