Polyipnus is a genus of oceanic ray-finned fish in the family Sternoptychidae. This is the largest genus of the marine hatchetfishes subfamily Sternoptychinae and indeed of the entire Sternoptychidae. It is not quite as apomorphic as their relatives; it may be that the genus is actually a paraphyletic assemblage of less advanced Sternoptychinae and would need to be split.
Fossils of this genus show that they have existed at least since the Early Oligocene, about 30 million years ago.
Species
There are currently 34 recognized species in this genus:
- Polyipnus aquavitus <small>R. C. Baird, 1971</small> (aquavit hatchetfish)
- Polyipnus asper <small>Harold, 1994</small>
- Polyipnus asteroides <small>L. P. Schultz, 1938</small>
- Polyipnus bruuni <small>Harold, 1994</small>
- Polyipnus clarus <small>Harold, 1994</small> (slope hatchetfish)
- Polyipnus danae <small>Harold, 1990</small>
- Polyipnus elongatus <small>Borodulina, 1979</small>
- Polyipnus fraseri <small>Fowler, 1934</small>
- Polyipnus indicus <small>L. P. Schultz, 1961</small>
- Polyipnus inermis <small>Borodulina, 1981</small>
- Polyipnus kiwiensis <small>R. C. Baird, 1971</small> (kiwi hatchetfish)
- Polyipnus laruei <small>Vourey, Dupoux & Harold, 2017</small> (bigeye hatchetfish)
- Polyipnus laternatus <small>Garman, 1899</small>
- Polyipnus latirastrus <small>Last & Harold, 1994</small> (comb-side hatchetfish)
- Polyipnus limatulus <small>Harold & Wessel, 1998</small>
- Polyipnus matsubarai <small>L. P. Schultz, 1961</small>
- Polyipnus meteori <small>Kotthaus, 1967</small>
- Polyipnus notatus <small>Harold, I. M. Kemp & Shore, 2016</small>
- Polyipnus nuttingi <small>C. H. Gilbert, 1905</small> (Nutting's hatchetfish)
- Polyipnus oluolus <small>R. C. Baird, 1971</small>
- Polyipnus omphus <small>R. C. Baird, 1971</small>
- Polyipnus ovatus <small>Harold, 1994</small>
- Polyipnus parini <small>Borodulina, 1979</small>
- Polyipnus paxtoni <small>Harold, 1989</small> (Paxton's hatchetfish)
- Polyipnus polli <small>L. P. Schultz, 1961</small> (round hatchetfish)
- Polyipnus ruggeri <small>R. C. Baird, 1971</small> (rugby hatchetfish)
- Polyipnus soelae <small>Harold, 1994</small> (Soela hatchetfish)
- Polyipnus spinifer <small>Borodulina, 1979</small>
- Polyipnus spinosus <small>Günther, 1887</small> (spiny hatchetfish)
- Polyipnus stereope <small>D. S. Jordan & Starks, 1904</small>
- Polyipnus surugaensis <small>Aizawa, 1990</small>
- Polyipnus tridentifer <small>McCulloch, 1914</small> (three-spined hatchetfish)
- Polyipnus triphanos <small>L. P. Schultz, 1938</small> (three-light hatchetfish)
- Polyipnus unispinus <small>L. P. Schultz, 1938</small>
References