The daggertooths are a genus of aulopiform

Aulopiformes

Aulopiformes is an order of marine ray-finned fish consisting of some 15 extant and several prehistoric families with about 45 genera and over 230 species. The common names grinners, lizardfishes and allies or aulopiforms are sometimes used for this group...

 fish, the sole genus of the family Anotopteridae. They are found in oceans worldwide, but prefer cooler waters.

Daggertooths are similar to the related lancetfish

Lancetfish

Lancetfishes are large oceanic predatory fishes in the genus Alepisaurus , the only living genus in the family Alepisauridae....

es in appearance, with a large mouth and dagger-like teeth. However, as their scientific name (meaning "without fins on its back") suggests, they lack the large 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 of the lancetfishes. They grow to as much as 147 centimetres (4.8 ft) in length.

Species

Only three species of the family and genus have so far been formally described:

Family Anotopteridae

• Genus Anotopterus
  • Anotopterus nikparini - North Pacific daggertooth
  • Anotopterus pharao
    Anotopterus pharao
    Daggertooth is a daggertooth described in 1911 by E. Zugmayer. The distribution occurs in the North Atlantic Ocean and west of Africa. The record size for this species is 96 cm and was hermaphroditic.Daggerteeth are occasionally found dead in bottom trawls that look for firefly squid or shrimp...
    
    
  • Anotopterus vorax
    Anotopterus vorax
    Anotopterus vorax or south ocean daggertooth is a daggertooth described in 1913 by Regan. A. vorax inhabits the South Pacific, South Atlantic, South Indian Ocean, and Antarctic Ocean.-References:...
    
    - South ocean daggertooth Regan, 1913

A possible fourth species

Anotopterus sp. (2008)

Anotopterus sp. is a species of daggertooth discovered in the New Zealand Antarctic Ocean, at 71°S, and is one of the southernmost species caught. Its golden luster and sapphire blue eyes are exquisite, unfortunately, however, the colors fade quickly when the fish is removed from its habitat. ...

was discovered in 2008, but has yet to receive a taxonomic name.