''Polypera'' is a

monospecific genus In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispec ...

of marine ray-finned fish belonging to the family

Liparidae The Liparidae, commonly known as snailfish or sea snails, are a family of marine scorpaeniform fishes. Widely distributed from the Arctic to Antarctic Oceans, including the oceans in between, the snailfish family contains more than 30 genera ...

, the snailfishes. It only species is ''Polypera simushirae'' which is found in the northwestern Pacific Ocean where it is found at depths down to . This species grows to a length of TL and has been recorded at a maximum weight of . This species is the only known member of its genus. It is probably, the largest of the snailfishes.

References

Liparidae Monotypic fish genera Fish described in 1912 {{Scorpaeniformes-stub