World Library  
Flag as Inappropriate
Email this Article

Sailfin roughshark

Article Id: WHEBN0007193901
Reproduction Date:

Title: Sailfin roughshark  
Author: World Heritage Encyclopedia
Language: English
Subject: Japanese roughshark, Squaliformes, Mandarin dogfish, Longnose pygmy shark, Smalleye pygmy shark
Collection:
Publisher: World Heritage Encyclopedia
Publication
Date:
 

Sailfin roughshark

Sailfin roughshark
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Chondrichthyes
Subclass: Elasmobranchii
Order: Squaliformes
Family: Oxynotidae
Genus: Oxynotus
Species: O. paradoxus
Binomial name
Oxynotus paradoxus
Frade, 1929
Range of the sailfin roughshark

The sailfin roughshark (Oxynotus paradoxus) is a species of dogfish shark in the family Oxynotidae, found in the eastern North Atlantic from Scotland to Senegal between latitudes 41°N and 11°N, at depths of between 265 and 720 m (869 and 2,362 ft). Its length is up to 1.2 m (3.9 ft).

Its reproduction is ovoviviparous.

O. paradoxus is thought to be a slow-moving predator of small benthic animal. The sailfin roughsharks is found near the Eastern Atlantic ocean at those depths. However, it has been reported to be found on the shores of Morocco, recently reported in the Mid-Atlantic Ridge, and in the Azores water. This species is an uncommon bycatch of bottom trawls, though there is insufficient information for the International Union for Conservation of Nature (IUCN) to assess its conservation status.[1]

Contents

  • Taxonomy 1
  • Description 2
  • Reproduction 3
  • Geographical habitat and Ecology 4
  • Diet 5
  • Threat and Conservation 6
  • References 7

Taxonomy

French biologist F. Frade founded this species of Oxynotus paradoxus. This name was later finalized and accepted by the scientific community as the official name for the species. Frade published his findings of this specimen in 1929 in the scientific journal Boletim da Sociedade Portuguesa de Ciências Naturais.[2]

Description

O. paradoxus is a rare shark found in the deep waters of the ocean from about 265–750 m below ocean level. At birth, O. paradoxus is about 25 cm in length and can grow up to 118 cm in length.[1] It has a compressed body form with a blunt snout and a wide, flattened head. O. paradoxus has two tall, narrow and pointed dorsal fins that contain concave trailing edges, but no anal fin. The first dorsal spine trails back, a unique feature of this species of Oxynotus. Both spiracles are relatively small compared to other sharks and are almost completely circular. The top teeth of O. paradoxus are lanceolate, but the lower teeth are blade-like. Each set of both upper and lower teeth contain 12 rows of teeth.[3] The flank dermal denticles contain a central cusp next to two lateral cusps and a second middle cusp above the primary cusp.[4]

Of all the Atlantic Oxynotus species, O. paradoxus is the only species to have an incline first dorsal fin spine. The color of the shark when living is uniform dark brown, however it turns black in preserved specimen.[4]

Reproduction

This species of shark is an ovoviviparous species, meaning the embryos develop inside eggs, which are retained inside the mother’s body until the eggs are ready to hatch. These shark pups are about 25 cm in length.[3]

Geographical habitat and Ecology

O. paradoxus lives in two separate places: Northeast Atlantic and Easter Central Atlantic. In the Northeast Atlantic along the Atlantic slope of Scotland and the Mid-Atlantic ridge. In the Eastern Central Atlantic from Morocco southward to the Gulf of Guinea.[3]

Based on the distribution of O. paradoxus, occupying a bathybenthic habitat, the species can be classified as


  1. ^ a b "Oxynotus paradoxus." (Sailfin Roughshark). N.p., n.d. Web. 30 November 2013. .
  2. ^ FRAde F., 1929. “Une nouvelle espèce ou une aberration individuelle de l’Oxynotus centrina” (Linn.). Bull. Soc. Port. Sci. Nat., 10(22): 263-267.
  3. ^ a b c d e f g h Hurst, Richard. "Factsheet: Sailfin Roughshark." Factsheet: Sailfin Roughshark. 30 November 2013. .
  4. ^ a b Azevedo, Jose, Fernando Sousa, and Joao Brium. "Dermal denticles and morphometrics of the sailfin roughshark Oxynotus paradoxus (elasmobranchii, oxynotidae), with comments on its geographic Distribution." Cybium 27 (2003): 117-122. .
  • Froese, Rainer and Pauly, Daniel, eds. (2006). "Oxynotus paradoxus in FishBase. July 2006 version.

References

Although this shark is a bycatch by offshore fisheries, it has little to no commercial uses. Though, when caught, the most probably use of O. paradoxus is fishmeal or bait.[3]

Since this species of shark lives in the depths where deepwater fisheries operate, they can have a negative impact on the already uncommon species by being the bycatch of these offshore fisheries. Although their population is unknown, most of its population is in the deeper offshore waters and very few are in the inshore waters.[3]

Threat and Conservation

The diet of O. paradoxus is largely unknown, however from reported sightings of the shark, it has been identified that these sharks feast on small benthic fish and invertebrates.[3]

Diet

As stated before, O. paradoxus if found in the depths of 265–800 m below sea level. Due to their poor ability to swim, O. paradoxus use their relatively large and oil filled livers to maintain their buoyancy.[3]

[3]

This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and USA.gov, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for USA.gov and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
 
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
 
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.
 



Copyright © World Library Foundation. All rights reserved. eBooks from World Library are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.