Medusafishes are a family, Centrolophidae, of

scombriform Scombriformes, also known as Pelagia and Pelagiaria, is an order of ray-finned fish within the clade Percomorpha. It contains 287 extant species in 16 families, most of which were previously classified under the suborders Scombroidei and Stroma ...

ray-finned fishes. The family includes about 31 species. They are found in temperate and tropical waters throughout the world. Young ''

Icichthys lockingtoni ''Icichthys lockingtoni'', commonly known as the medusafish, is a species of centrolophid ray-finned fish native to the northern Pacific Ocean, where it ranges from Japan and the Gulf of Alaska to central Baja California in Mexico. It typically ...

'' specimens are abundant in the coastal waters of the north

Pacific The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean, or, depending on the definition, to Antarctica in the south, and is bounded by the cont ...

, where they are often found in association with

jellyfish Jellyfish, also known as sea jellies or simply jellies, are the #Life cycle, medusa-phase of certain gelatinous members of the subphylum Medusozoa, which is a major part of the phylum Cnidaria. Jellyfish are mainly free-swimming marine animal ...

, which provide them with protection from predators and opportunities to scavenge the remains of the jellyfishes' meals. The oldest known fossil member of the group known from articulated remains is '' Butyrumichthys'' from the earliest

Ypresian In the geologic timescale the Ypresian is the oldest age (geology), age or lowest stage (stratigraphy), stratigraphic stage of the Eocene. It spans the time between , is preceded by the Thanetian Age (part of the Paleocene) and is followed by th ...

of the

Fur Formation The Fur Formation is a marine geological formation of Ypresian ( Lower Eocene Epoch, c. 56.0-54.5 Ma) age which crops out in the Limfjord region of northern Denmark from Silstrup via Mors and Fur to Ertebølle, and can be seen in many cliffs and ...

in Denmark. Slightly older fossil

otoliths An otolith (, ' ear + , ', a stone), also called otoconium, statolith, or statoconium, is a calcium carbonate structure in the saccule or utricle of the inner ear, specifically in the vestibular system of vertebrates. The saccule and utricle, i ...

of the species ''"Mupus" sinuosus'' are also known from the

Selandian The Selandian is a stage in the Paleocene. It spans the time between . It is preceded by the Danian and followed by the Thanetian. Sometimes the Paleocene is subdivided in subepochs, in which the Selandian forms the "middle Paleocene". Stratig ...

of Denmark.

Genera

The following genera are classified within the family Centrolophidae: * ''

Centrolophus The black ruff (''Centrolophus niger'') is a medusafish, the only member of the genus ''Centrolophus''. It is a pelagic fish found in all tropical and temperate oceans at depths of . Its length is typically up to , but it may reach . Other commo ...

'' Lacépède, 1802 * ''

Hyperoglyphe ''Hyperoglyphe'' is a genus of medusafishes native to the Atlantic and Pacific oceans. Species There are currently six recognized species in this genus: * ''Hyperoglyphe antarctica'' ( Carmichael, 1819) (Bluenose warehou) * '' Hyperoglyphe bythi ...

'' Günther, 1859 * ''

Icichthys ''Icichthys'' is a genus of medusafishes that are native to the eastern Indian Ocean and the northern Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five Borders of the oceans, oceanic divisions. It extends from th ...

Jordan Jordan, officially the Hashemite Kingdom of Jordan, is a country in the Southern Levant region of West Asia. Jordan is bordered by Syria to the north, Iraq to the east, Saudi Arabia to the south, and Israel and the occupied Palestinian ter ...

& Gilbert, 1880 * ''

Psenopsis ''Psenopsis'' is a genus of medusafishes native to the Indian Ocean and the western Pacific Ocean. Species There are currently six recognized species in this genus: * '' Psenopsis anomala'' (Temminck & Schlegel, 1844) (Pacific rudderfish) * '' ...

Gill A gill () is a respiration organ, respiratory organ that many aquatic ecosystem, aquatic organisms use to extract dissolved oxygen from water and to excrete carbon dioxide. The gills of some species, such as hermit crabs, have adapted to allow r ...

, 1862 * ''

Schedophilus ''Schedophilus'' is a genus of ray-finned fish in the family Centrolophidae, the medusafish. The genus has a global distribution. Species There are currently eight recognized species in this genus: * '' Schedophilus griseolineatus'' (Norman, 19 ...

'' Cocco, 1839 * ''

Seriolella ''Seriolella'' is a genus of medusafishes native to the southwestern Pacific Ocean and the eastern Indian Ocean. Species There are currently six recognized species in this genus: * ''Seriolella brama'' ( Günther, 1860) (Blue warehou or common w ...

'' Guichenot, 1848 * ''

Tubbia ''Tubbia'', is a genus of ray-finned fish in the family Centrolophidae. Species There are currently 2 recognized species in this genus: * '' Tubbia stewarti'' Last A last is a mechanical form shaped like a human foot. It is used by shoe ...

'' Whitley, 1943 The following fossil genera are also known: * †'' Agarcia'' Baciu & Bannikov, 2004 (

Early Oligocene The Rupelian is, in the geologic timescale, the older of two age (geology), ages or the lower of two stage (stratigraphy), stages of the Oligocene epoch (geology), Epoch/series (stratigraphy), Series. It spans the time between . It is preceded b ...

Romania Romania is a country located at the crossroads of Central Europe, Central, Eastern Europe, Eastern and Southeast Europe. It borders Ukraine to the north and east, Hungary to the west, Serbia to the southwest, Bulgaria to the south, Moldova to ...

) * †'' Butyrumichthys'' Schrøder, Rasmussen, Møller & Carnevale, 2022 (Early Eocene of Denmark) * †'' Petrodavia'' Baciu & Bannikov, 2004 (Early Oligocene of Romania) * †'' Zorzinia'' Bannikov, 2000 (Early Eocene of Italy) The placements of ''Butyrumichthys'', ''Petrodavia'', and ''Agarcia'' are tentative.

Timeline of genera

ImageSize = width:1000px height:auto barincrement:15px PlotArea = left:10px bottom:50px top:10px right:10px Period = from:-65.5 till:10 TimeAxis = orientation:horizontal ScaleMajor = unit:year increment:5 start:-65.5 ScaleMinor = unit:year increment:1 start:-65.5 TimeAxis = orientation:hor AlignBars = justify Colors = #legends id:CAR value:claret id:ANK value:rgb(0.4,0.3,0.196) id:HER value:teal id:HAD value:green id:OMN value:blue id:black value:black id:white value:white id:cenozoic value:rgb(0.54,0.54,0.258) id:paleogene value:rgb(0.99,0.6,0.32) id:paleocene value:rgb(0.99,0.65,0.37) id:eocene value:rgb(0.99,0.71,0.42) id:oligocene value:rgb(0.99,0.75,0.48) id:neogene value:rgb(0.999999,0.9,0.1) id:miocene value:rgb(0.999999,0.999999,0) id:pliocene value:rgb(0.97,0.98,0.68) id:quaternary value:rgb(0.98,0.98,0.5) id:pleistocene value:rgb(0.999999,0.95,0.68) id:holocene value:rgb(0.999,0.95,0.88) BarData= bar:eratop bar:space bar:periodtop bar:space bar:NAM1 bar:NAM2 bar:space bar:period bar:space bar:era PlotData= align:center textcolor:black fontsize:M mark:(line,black) width:25 shift:(7,-4) bar:periodtop from: -65.5 till: -55.8 color:paleocene text:

Paleocene The Paleocene ( ), or Palaeocene, is a geological epoch (geology), epoch that lasted from about 66 to 56 mya (unit), million years ago (mya). It is the first epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), ...

from: -55.8 till: -33.9 color:eocene text:

Eocene The Eocene ( ) is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes ...

from: -33.9 till: -23.03 color:oligocene text:

Oligocene The Oligocene ( ) is a geologic epoch (geology), epoch of the Paleogene Geologic time scale, Period that extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that defin ...

from: -23.03 till: -5.332 color:miocene text:

Miocene The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...

from: -5.332 till: -2.588 color:pliocene text: Plio. from: -2.588 till: -0.0117 color:pleistocene text:

Pleist. The Pleistocene ( ; referred to colloquially as the ''ice age, Ice Age'') is the geological epoch (geology), epoch that lasted from to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fin ...

from: -0.0117 till: 0 color:holocene text: H. bar:eratop from: -65.5 till: -23.03 color:paleogene text:

Paleogene The Paleogene Period ( ; also spelled Palaeogene or Palæogene) is a geologic period and system that spans 43 million years from the end of the Cretaceous Period Ma (million years ago) to the beginning of the Neogene Period Ma. It is the fir ...

from: -23.03 till: -2.588 color:neogene text:

Neogene The Neogene ( ,) is a geologic period and system that spans 20.45 million years from the end of the Paleogene Period million years ago ( Mya) to the beginning of the present Quaternary Period million years ago. It is the second period of th ...

from: -2.588 till: 0 color:quaternary text: Q. PlotData= align:left fontsize:M mark:(line,white) width:5 anchor:till align:left color:eocene bar:NAM1 from: -55.8 till: 0 text: Mupus color:miocene bar:NAM2 from: -23.03 till: 0 text:

PlotData= align:center textcolor:black fontsize:M mark:(line,black) width:25 bar:period from: -65.5 till: -55.8 color:paleocene text:

from: -55.8 till: -33.9 color:eocene text:

from: -33.9 till: -23.03 color:oligocene text:

from: -23.03 till: -5.332 color:miocene text:

from: -5.332 till: -2.588 color:pliocene text: Plio. from: -2.588 till: -0.0117 color:pleistocene text:

from: -0.0117 till: 0 color:holocene text: H. bar:era from: -65.5 till: -23.03 color:paleogene text:

from: -23.03 till: -2.588 color:neogene text:

from: -2.588 till: 0 color:quaternary text: Q.

References

Taxa named by Charles Lucien Bonaparte {{Scombroidei-stub