Wednesday, August 7, 2013

The Frilled Shark





The Frilled Shark  
      Chlamydoselachus anguineus

The frilled shark is a rare deep-water species. It poses no threat to humans due to the fact it lives where it is not likely to encounters people.


Identification:
The frilled shark's most identifiable feature is its long, eel-like body.



It is dark to light brown with darker fin edges. It has a long lower jaw and an enormous gape. It has six gill slits, the first of which goes continuously underneath the head.


Frilled sharks also only have one dorsal fin, located by the base of the caudal fin. Its caudal fin is almost completely an upper lobe.


Classification:
Kingdom : Animalia
Phylum : Chordata
Subphylum : Vertebrata
Class : Chondrichthyes
Subclass :  Elasmobranchii
Order : Hexanchiformes
Family : Chlamydoselachidae
Genus : Chlamydoselachus
Species : anguineus


Similar Species and Other Family Members:
There are speculations that the frilled sharks that live in South Africa are a different species, the South African frilled shark.


Reproduction:
Frilled sharks are ovoviviparous. We do not know their age of maturity. Frilled sharks are believed to give birth to 12 young. We do not know the frilled sharks' gestation period, however it has been estimated to a year or more due to the large size of the eggs.


Size:
 Male frilled sharks are believed to be sexually mature at 110 cm (3.6 feet), while females are sexually mature at about 135 cm (4.4 feet). The maximum reported length is 196 cm (6.4 feet).


Diet: 
Most of what the frilled shark feeds on is unknown. However, we do know that  it does eat squid and bony fish.


Teeth & Jaws:
Here is an image of frilled shark teeth. These teeth are perfect for snatching slippery prey, such as squid.




Habitat and Distribution:
Frilled sharks are found all over the world. They are most common at depths of 50-200 meters (160-660 ft), but they have been found as deep as 1,570 meters (5,150 ft).


Lifespan:
The lifespan is unknown. Since we cannot tag or track these sharks and they do not survive in captivity, we can't tell their life span.


Conservation Status:
According to the IUCN Red List of Threatened Species, the frilled shark is near threatened. They are generally a rare species. They are not actively fished, but a regular bycatch in many bottom trawl, midwater trawl, deep-set longline, and deep-set gillnet fisheries.



sources:
The Sharks of North America, Jose I. Castro
http://en.wikipedia.org/wiki/Frilled_shark
Sharkpedia, DK Publishing 
http://www.elasmo-research.org/education/ecology/deepsea-frilled_shark.htm
http://www.iucnredlist.org/details/41794/0
note: none of the images are mine

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