Angel sharks

Taxobox
name = Angel sharks
fossil_range = Late Oxfordian to Present [cite journal
last = Sepkoski
first = Jack
authorlink =
coauthors =
title = A compendium of fossil marine animal genera (Chondrichthyes entry)
journal = Bulletins of American Paleontology
volume = 364
issue =
pages = p.560
publisher =
location =
date = 2002
url = http://strata.ummp.lsa.umich.edu/jack/showgenera.php?taxon=575&rank=class
doi =
id =
accessdate = 2008-01-09 ]
status = CR
status_system = iucn3.1
extinct =


image_width = 250px
image_caption = Sand devil, "Squatina dumeril"
regnum = Animalia
phylum = Chordata
classis = Chondrichthyes
subclassis = Elasmobranchii
ordo = Squatiniformes
ordo_authority = Buen, 1926
familia = Squatinidae
familia_authority = Bonaparte, 1838
genus = "Squatina"
genus_authority = Duméril, 1806
subdivision_ranks = Species
subdivision = See text.

The angel sharks are an unusual genus of sharks with flattened bodies and broad pectoral fins that give them a strong resemblance to skates and rays. The 16-odd known species are in the genus "Squatina", the only genus in its family, Squatinidae, and order Squatiniformes. They occur worldwide in temperate and tropical seas.

Appearance

While the forward part of the angel shark's body is broad and flattened, the rear part retains a muscular appearance more typical of other sharks. The eyes and spiracles are on top, and the five gill slits are on bottom. Both the pectorals and the pelvic fins are large and held horizontally. There are two dorsal fins, no anal fin, and unusually for sharks, the lower lobe of the caudal fin is longer than the upper lobe. Most types grow to a length of 1.5 m (5 ft), with the Japanese angel shark, "Squatina japonica", known to reach 2 m.

Habitat

Angel sharks bury themselves in sand or mud, and then jump up to snap up prey, which includes fish, crustaceans, and various types of mollusks.

Behavior

Although they are not normally aggressive, they do bite when stepped on or handled. If they are left alone they will not attack.

Reproduction

Angel sharks are ovoviviparous, with litters known up to 13 pups.

Commercial value

The sharks were long considered of no commercial interest, but in 1978, Michael Wagner, a fish processor in Santa Barbara, California, began to promote angel sharks, and 310 metric tons were taken off California in 1984. The fishery devastated the population and is now regulated.

Protection

Angel sharks have historically been heavily fished but education has played a role in reducing over fishing of these slow-reproducing chondrichthyes. In April 2008 the UK Government afforded the angel shark full protection under the Wildlife and Countryside Act.

Species

* Sawback angelshark, "Squatina aculeata" Cuvier, 1829
* African angelshark, "Squatina africana" Regan, 1908
* Argentine angelshark, "Squatina argentina" (Marini, 1930)
* Chilean angelshark, "Squatina armata" (Philippi, 1887)
* Australian angelshark, "Squatina australis" Regan, 1906
* Pacific angelshark, "Squatina californica" Ayres, 1859
* Sand devil, "Squatina dumeril" Lesueur, 1818
* Taiwan angelshark, "Squatina formosa" Shen & Ting, 1972
* Angular angel shark, "Squatina guggenheim" Marini, 1936
* Japanese angelshark, "Squatina japonica" Bleeker, 1858
* Clouded angelshark, "Squatina nebulosa" Regan, 1906
* Smoothback angelshark, "Squatina oculata" Bonaparte, 1840
* "Squatina punctata" Marini, 1936
* "Squatina squatina" (Linnaeus, 1758)
* Ornate angelshark, "Squatina tergocellata" McCulloch, 1914
* Ocellated angelshark, "Squatina tergocellatoides" Chen, 1963
* Eastern Australian angelshark, Squatina sp. A (provisional scientic name)
* Western Australian angelshark, Squatina sp. B (provisional scientic name)
* Cortez angelshark, Squatina sp. (provisional scientic name)

References

*
* [http://www.defra.gov.uk/news/2008/080226a.htm] DEFRA news release.

See also

* List of sharks

External links

* OceanFootage [http://www.oceanfootage.com/stockfootage/angel_shark_video_clips Angel Shark Images and Video Clips]
* [http://www.elasmo-research.org/education/shark_profiles/squatiniformes.htm Reefquest page on angel sharks]
* [http://www.mbayaq.org/efc/living_species/default.asp?hOri=1&inhab=484 Monterey Bay Aquarium page on Pacific angel shark]
* http://www.elasmo-research.org/education/topics/d_checklist.htm (also a reference)