Houndsharks are a family, Triakidae, of ground sharks

Carcharhiniformes

The ground sharks, order Carcharhiniformes, are the largest order of sharks. With over 270 species, carcharhiniforms include a number of common types, such as the blue shark, catsharks, swellsharks, and sandbar shark....

, consisting of about 40 species in 9 genera. In some classifications, the family is split into two sub-families, with Mustelus, Scylliogaleus, and Triakis

Triakis

Triakis is a genus of houndshark in the family Triakidae.The name comes from the Latin word tri meaning "three", and acis meaning "sharp" or "pointed", in reference to the three-pointed teeth of these sharks.-Species:* Subgenus Cazon...

in sub-family Triakinae, and the remaining genera in sub-family Galeorhininae.

Houndsharks are distinguished by possessing two large spineless dorsal fin

Dorsal fin

A dorsal fin is a fin located on the backs of various unrelated marine and freshwater vertebrates, including most fishes, marine mammals , and the ichthyosaurs...

s, an anal fin, and oval eyes with nictitating eyelids. They are small to medium in size, ranging from 37 centimetres (14.6 in) to 220 centimetres (7.2 ft) in adult length. They are found throughout the world in warm and temperate waters, where they feed on fish and invertebrates on the seabed and in midwater.

Genera

• Furgaleus Whitley
  Gilbert Percy Whitley
  Gilbert Percy Whitley was a British-born Australian ichthyologist and malacologist who was Curator of Fishes at the Australian Museum in Sydney for about 40 years. He was born at Swaythling, Southampton, England, and was educated at King Edward VI School, Southampton and Osborne House...
  
  , 1951
• Galeorhinus Blainville
  Henri Marie Ducrotay de Blainville
  Henri Marie Ducrotay de Blainville was a French zoologist and anatomist.Blainville was born at Arques, near Dieppe. In about 1796 he went to Paris to study painting, but he ultimately devoted himself to natural history, and attracted the attention of Georges Cuvier, for whom he occasionally...
  
  , 1816
• Gogolia Compagno, 1973
• Hemitriakis
  Hemitriakis
  Hemitriakis is a genus of houndshark in the family Triakidae.-Species:* Hemitriakis abdita Compagno & Stevens, 1993 * Hemitriakis complicofasciata Takahashi & Nakaya, 2004...
  
  Herre
  Albert William Herre
  Albert William Christian Theodore Herre was an American ichthyologist and lichenologist.Herre was born in 1868 in Toledo, Ohio....
  
  , 1923
• Hypogaleus J. L. B. Smith, 1957
• Iago
  Iago (genus)
  Iago is a genus of houndshark in the family Triakidae.The name comes from the villain in Shakespeare´s Othello.-Species:* Iago garricki Fourmanoir & Rivaton, 1979 * Iago omanensis...
  
  Compagno & Springer
  Stewart Springer
  Stewart Springer, was a world renowned expert on shark behavior, classification , and distribution of shark populations. There are more than 35 species of sharks, skates, rays, and other animals either classified originally by him or named after him.-Education:Springer was a field naturalist,...
  
  , 1971
• Mustelus H. F. Linck, 1790
• Scylliogaleus Boulenger
  George Albert Boulenger
  George Albert Boulenger FRS was a Belgian-British zoologist who identified over 2000 new animal species, chiefly fish, reptiles and amphibians.-Life:...
  
  , 1902
• Triakis
  Triakis
  Triakis is a genus of houndshark in the family Triakidae.The name comes from the Latin word tri meaning "three", and acis meaning "sharp" or "pointed", in reference to the three-pointed teeth of these sharks.-Species:* Subgenus Cazon...
  
  J. P. Müller
  Johannes Peter Müller
  Johannes Peter Müller , was a German physiologist, comparative anatomist, and ichthyologist not only known for his discoveries but also for his ability to synthesize knowledge.-Early years and education:...
  
   & Henle
  Friedrich Gustav Jakob Henle
  Friedrich Gustav Jakob Henle was a German physician, pathologist and anatomist. He is credited with the discovery of the loop of Henle in the kidney. His essay "On Miasma and Contagia" was an early argument for the germ theory of disease...
  
  , 1839

Cladogram

• Triakidae
  • Triakinae
    • Scylliogaleini
      • Scylliogaleus
    • Triakini
      • Mustelus
      • Triakis
        • Subgenus Triakis
        • Subgenus Cazon (may be a genus)
  • Galeorhininae
    • Galeorhinini
      • Galeorhinus
      • Hypogaleus
    • Iagini
      • Gogolia
      • Hemitriakis
      • Iago