Spiny dogfish
Conservation status
Vulnerable
Scientific classification
Kingdom: Animalia Phylum: Chordata Class: Chondrichthyes Subclass: Elasmobranchii Order: Squaliformes Family: Squalidae Genus: Squalus Species: S. acanthias
Binomial name
Squalus acanthias Linnaeus, 1758

Sharks Portal

The spiny dogfish or piked dogfish, Squalus acanthias, is one of the best known of the dogfish, members of the family Squalidae in the order Squaliformes. There are actually several species to which the names are applied, but all are readily distinguished by their having two spines (one anterior to each dorsal fin) and their lack of an anal fin. It is found in shallow waters and offshore in most parts of the world, especially in temperate waters. This article explains how to read a taxobox. ... Download high resolution version (896x240, 19 KB)Spiny Dogfish From http://www. ... The conservation status of a species is an indicator of the likelihood of that species continuing to survive either in the present day or the future. ... Image File history File links Status_iucn3. ... This list is incomplete; you can help by expanding it. ... For other uses, see Scientific classification (disambiguation). ... Animalia redirects here. ... {{{subdivision_ranks}}} See below Chordates (phylum Chordata) are a group of animals that includes the vertebrates, together with several closely related invertebrates. ... Subclasses and Orders See text. ... Superorders Galeomorpha Batoidea Selachimorpha Elasmobranchii is the subclass of cartilaginous fishes that includes skates, rays and sharks. ... Families Squalidae (dogfish sharks) Centrophoridae (gulper sharks) Dalatiidae (sleeper sharks) Echinorhinidae (bramble sharks) Squaliformes is an order of sharks that includes the smooth dogfish and spiny dogfish and others, about 80 species in four families. ... Genera See text. ... Species See text. ... In biology, binomial nomenclature is the formal method of naming species. ... Carolus Linnaeus, also known after his ennoblement as  , (May 23, 1707 – January 10, 1778), was a Swedish botanist, physician and zoologist[1] who laid the foundations for the modern scheme of nomenclature. ... Image File history File linksMetadata Greyreefsharksmall2. ... Spiny Dogfish, Squalus acanthias The name dogfish is applied to a number of small sharks found in the northeast Atlantic, Pacific, and Mediterranean, especially those in the three families Scyliorhinidae, Dalatiidae and Squalidae. ... In biological classification, family (Latin: familia, plural familiae) is 1) a rank or 2) a taxon in that rank. ... Genera See text. ... Families Squalidae (dogfish sharks) Centrophoridae (gulper sharks) Dalatiidae (sleeper sharks) Echinorhinidae (bramble sharks) Squaliformes is an order of sharks that includes the smooth dogfish and spiny dogfish and others, about 80 species in four families. ... Dorsal Fin of the Orca A dorsal fin is a fin located on the backs of fishes, whales, dolphins and porpoises. ... Fish anatomy is primarily governed by the physical characteristics of water, which is much denser than air, holds a relatively small amount of dissolved oxygen, and absorbs light more than does air. ...

Morphology and behavior

The spiny dogfish has dorsal spines, no anal fin, and white spots along its back. The caudal fin has asymmetrical lobes, forming a heterocercal tail. Males mature at around 11 years of age, growing to 80-100 cm in length; females mature in 18-21 years and are slightly larger than males, reaching 100-124 cm. Both sexes are greyish brown in color and are countershaded. Males are identified by a pair of pelvic fins modified as sperm-transfer organs, or "claspers". The male inserts one clasper into the female cloaca during copulation. Countershading employed by the great white shark. ...

The species name acanthias refers to the shark's two spines. These are used defensively; if captured, the shark can arch its back to pierce its captor. Glands at the base of the spines secrete a mild poison.

The spiny dogfish forms large schools of hundreds to thousands of sharks. It is from this behavior that their name is derived, as fisherman likened these large schools to packs of dogs. Schools are often composed entirely of sharks of like size and sex. The shark feeds on bony fishes, smaller sharks, and various invertebrates. It is also a common prey item for large fish, other sharks, and marine mammals. Invertebrate is a term coined by Jean-Baptiste Lamarck to describe any animal without a spinal column. ...

Reproduction is ovoviviparous. Fertilization is internal. The male inserts one claspers into the female oviduct orifice and injects sperm along a groove on the clasper's dorsal section. Immediately following fertilization, the eggs are surrounded by thin shells called candles, with one candle usually surrounding several eggs. Mating takes place in the winter months, with gestation lasting 22-24 months (the longest of any vertebrate). Litters range between 2 and 11 but average 6 or 7. Ovoviviparous animals develop within eggs that remain within the mother up until they hatch or are about to. ...

Commercial use

Spiny dogfish are fished for food in Europe, the United States, Canada, New Zealand and Chile. The meat is primarily consumed in England, France, the Benelux countries and Germany. The fins and tails are processed into fin needles and are used in less expensive versions of shark fin soup in Chinese cuisine. In England it is sold in "fish and chip shops" as "rock salmon", in France it is sold as "small salmon" (saumonette) and in Belgium it is sold as "sea eel" (zeepaling). It is also used as fertilizer, liver oil, and pet food, and, because of its availability and manageable size, as a popular vertebrate dissection specimen, especially in high schools. World map showing Europe A satellite composite image of Europe Europe is one of the seven traditional continents of the Earth. ... Motto: (French for God and my right) Anthem: God Save the King/Queen Capital London Largest city London Official language(s) English (de facto) Unification    - by Athelstan AD 927  Area    - Total 130,395 km² (1st in UK)   50,346 sq mi  Population    - 2006 est. ... Satellite image of the Benelux countries Belgium Netherlands Luxembourg Benelux Benelux (or Bénélux) is an economic union in Western Europe comprising three neighbouring monarchies, Belgium, the Netherlands, and Luxembourg. ... Classes and Clades See below Vertebrates are members of the subphylum Vertebrata (within the phylum Chordata), specifically, those chordates with backbones or spinal columns. ...

See also

• List of sharks

// Sharks belong to the superorder Selachimorpha in the subclass Elasmobranchii in the class Chondrichthyes. ...

References

• Fordham et al (2006). Squalus acanthias. 2006 IUCN Red List of Threatened Species. IUCN 2006. Retrieved on 11 May 2006. Database entry includes a lengthy justification of why this species is vulnerable
• Squalus acanthias (TSN 160617). Integrated Taxonomic Information System. Accessed on 24 January 2006.
• "Squalus acanthias". FishBase. Ed. Ranier Froese and Daniel Pauly. 10 2005 version. N.p.: FishBase, 2005.

The IUCN Red List of Threatened Species (also known as the IUCN Red List and Red Data List), created in 1963, is the worlds most comprehensive inventory of the global conservation status of plant and animal species. ... The World Conservation Union or International Union for the Conservation of Nature and Natural Resources (IUCN) is an international organization dedicated to natural resource conservation. ... Please note that the ITIS system URL has changed (25 September 2006). ... January 24 is the 24th day of the year in the Gregorian calendar. ... 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... FishBase is a comprehensive database of information about fish. ...

External links

• Spiny dogfish attacked by North Pacific Giant Octopus