Spinyfins are a family, Diretmidae, of beryciform fishes. The name is from Greek

Greek language

Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...

, di meaning "two" and eretmos meaning "oar". They are found worldwide in deep waters, down to as much as 2000 metres (6,561.7 ft).

As the common name implies, spinyfins have heavy spines along their fins. They have a deep, compressed body, and mouths that are almost vertically aligned. They are dark silver in colour, and reach up to 37 centimetres (14.6 in) in length.

Genera and species in the family Diretmidae

There are four living species in three genera: A fifth species, the extinct Absalomichthys velifer, is from the Late Miocene

Miocene

The Miocene is a geological epoch of the Neogene Period and extends from about . The Miocene was named by Sir Charles Lyell. Its name comes from the Greek words and and means "less recent" because it has 18% fewer modern sea invertebrates than the Pliocene. The Miocene follows the Oligocene...

 of Southern California

Southern California

Southern California is a megaregion, or megapolitan area, in the southern area of the U.S. state of California. Large urban areas include Greater Los Angeles and Greater San Diego. The urban area stretches along the coast from Ventura through the Southland and Inland Empire to San Diego...

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• †Genus Absalomichthys
  Absalomichthys
  Absalomichthys velifer is an extinct, prehistoric spinyfin that lived during the Upper Miocene of what is now Southern California. Its dorsal fin was huge in comparison with living species.-See also:* Prehistoric fish* List of prehistoric bony fish...
  
  
  • †Absalomichthys velifer Whitley 1933
• Genus Diretmus
  • Silver spinyfin
    Silver spinyfin
    The silver spinyfin, Diretmus argenteus, is a spinyfin of the genus Diretmus, found around the world except the Mediterranean, at depths down to 2,000 m. It belongs to the monotypic genus Diretmus...
    
    , Diretmus argenteus Johnson, 1864
• Genus Diretmichthys
  • Parin's spinyfin
    Parin's spinyfin
    Parin's spinyfin, Diretmichthys parini, is a spinyfin of the monotypic genus Diretmichthys. Adults are found in oceans at depths of between 500 m to 2100 m. It is also known as Malcarado de Parin. Its length is up to 40 cm.-Distribution:...
    
    , Diretmichthys parini (Post & Quéro, 1981)
• Genus Diretmoides
  • Longwing spinyfin, Diretmoides pauciradiatus (Woods, 1973)
  • Diretmoides veriginae Kotlyar, 1987