Frilled shark

Frill shark
Conservation status
Near Threatened
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Chondrichthyes
Subclass:	Elasmobranchii
Order:	Hexanchiformes
Family:	Chlamydoselachidae Garman, 1884
Genus:	Chlamydoselachus
Species:	C. anguineus
Binomial name
Chlamydoselachus anguineus Garman, 1884

Template:Sharksportal The frill shark or frilled shark, Chlamydoselachus anguineus, is a primitive shark species, the sole living member of the family Chlamydoselachidae in the order Hexanchiformes. It is very different from the other hexanchiform sharks, and it has been recently proposed that the frill shark should be given its own order: Chlamydoselachiformes. Additional extinct types are known from fossil teeth; thought to be extinct itself, it was only discovered in Japanese waters in the 19th century.(Allen, 48)

Superficially the frilled shark resembles a dark brown or gray eel, but the six gill slits identify it as a shark. The tissue of the gill slits protudes somewhat, thus inspiring the common name. Its dorsal fin is small, anal fin large, and the caudal fin (tail fin) is highly asymmetric, the ventral part almost unnoticeable. Its teeth are small, tricuspid, and very sharp. It has been recorded at up to 2 m in length.

Distribution is worldwide, but they seem to be uncommon across this range. The sharks are usually found at depths of 120 m to 1,300 m. They typically eat other sharks, squid, and bony fish.

Reproduction is not well understood, but like many other sharks they bear live young (ovoviviparous), with litter sizes of 2 to 12 pups. Compagno states "They are pregnant for a long time, probably one to two years". This would give the frill shark the possibility of having the longest gestation of any vertebrate, even exceeding the elephant's period of 22 months.

Frilled sharks appear regularly in the catches from bottom trawling, and when caught are used as food or for fishmeal.

See also

• List of sharks
• Hexanchiformes
• Time range of Hexanchiformes species

References

• Template:IUCN2006 Database entry includes justification for why this species is near threatened
• "Chlamydoselachus anguineus". Integrated Taxonomic Information System. 23 January. {{cite web}}: Check date values in: |date= and |year= / |date= mismatch (help)
• Allen, Thomas B. The Shark Almanac. New York: The Lyons Press, 1999. ISBN 1-55821-582-4
• Compagno, Dando, & Fowler, Sharks, Collins Gem, HarperCollins, London 2006) ISBN 0-00-721986-5

External links

• FishBase entry for Chlamydoselachus anguineus
• More info