Hiodontidae, commonly called mooneyes, is a

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

ray-finned fish Actinopterygii (; ), members of which are known as ray-finned fish or actinopterygians, is a class of bony fish that comprise over 50% of living vertebrate species. They are so called because of their lightly built fins made of webbings of sk ...

with a single included genus ''Hiodon''. The genus comprise two extant species native to North America and three to five extinct species recorded from

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), ...

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 ...

age fossils. They are large-eyed, fork-tailed fish that superficially resemble

shad The Alosidae, or the shads, are a family (biology), family of clupeiform fishes. The family currently comprises four genera worldwide, and about 32 species. The shads are Pelagic fish, pelagic (open water) schooling fish, of which many are anadr ...

s. The vernacular name comes from the metallic shine of their eyes. The higher classification of the mooneyes is not yet fully established. Some sources have place them in their own order,

Hiodontiformes Hiodontiformes is an order of ray-finned fish consisting of the two living species of the mooneye family, Hiodontidae, and three extinct genera. These are traditionally classified within the order Osteoglossiformes, a placement some authori ...

, while others retain them in the order

Osteoglossiformes Osteoglossiformes , meaning "bony tongues" in Ancient Greek, is a relatively primitive order of ray-finned fish that contains two sub-orders, the Osteoglossoidei and the Notopteroidei. All of at least 245 living species inhabit freshwater. They ...

Species

*''

Hiodon alosoides The goldeye (''Hiodon alosoides'') is a freshwater fish found in Canada and the northern United States. It is one of only two extant species in the family Hiodontidae, the other species being '' Hiodon tergisus''. The species name ''alosoides ...

'' (Rafinesque, 1819) The goldeye, ''Hiodon alosoides'', is widespread across eastern North America, and is notable for a conspicuous golden iris in the eyes. It prefers turbid slower-moving waters of lakes and rivers, where it feeds on a wide variety of organisms including insects,

crustacean Crustaceans (from Latin meaning: "those with shells" or "crusted ones") are invertebrate animals that constitute one group of arthropods that are traditionally a part of the subphylum Crustacea (), a large, diverse group of mainly aquatic arthrop ...

s, small fish, and

mollusk Mollusca is a phylum of protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant species of molluscs are recognized, making it the second-largest animal phylum after Arthropoda. The ...

s. The fish has been reported up to in length. *†''

Hiodon consteniorum Hiodontidae, commonly called mooneyes, is a family of ray-finned fish with a single included genus ''Hiodon''. The genus comprise two extant species native to North America and three to five extinct species recorded from Paleocene to Eocene age ...

'' Li & Wilson, 1994 *†''

Hiodon falcatus Hiodontidae, commonly called mooneyes, is a family of ray-finned fish with a single included genus ''Hiodon''. The genus comprise two extant species native to North America and three to five extinct species recorded from Paleocene to Eocene age ...

'' (Grande, 1979) *†''

Hiodon rosei Hiodontidae, commonly called mooneyes, is a family (biology), family of Actinopterygii, ray-finned fish with a single monotypic, included genus ''Hiodon''. The genus comprise two extant species native to North America and three to five extinct s ...

'' (Hussakof, 1916) *''

Hiodon tergisus ''Hiodon tergisus'', the mooneye, is a freshwater fish that is widespread across eastern North America. Anatomy and appearance ''H. tergisus'' is characterized by its silvery appearance, strongly compressed deep body, and keel that extends from ...

'' Lesueur, 1818 The mooneye, ''Hiodon tergisus'', is also widespread across eastern

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

, living in the clear waters of lakes, ponds, and rivers. It consumes aquatic

invertebrate Invertebrates are animals that neither develop nor retain a vertebral column (commonly known as a ''spine'' or ''backbone''), which evolved from the notochord. It is a paraphyletic grouping including all animals excluding the chordata, chordate s ...

insect Insects (from Latin ') are Hexapoda, hexapod invertebrates of the class (biology), class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (Insect morphology#Head, head, ...

s, and

fish A fish (: fish or fishes) is an aquatic animal, aquatic, Anamniotes, anamniotic, gill-bearing vertebrate animal with swimming fish fin, fins and craniate, a hard skull, but lacking limb (anatomy), limbs with digit (anatomy), digits. Fish can ...

. Mooneyes can reach in length. *†''

Hiodon woodruffi ''Hiodon woodruffi'' is an extinct species of bony fish in the mooneye family, Hiodontidae. The species is known from fossils found in the early Eocene deposits of northern Washington state in the United States and late Eocene deposits in north ...

'' Wilson, 1978 An

Early Eocene 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 ...

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 ...

Late Eocene The Priabonian is, in the International Commission on Stratigraphy, ICS's geologic timescale, the latest age (geology), age or the upper stage (stratigraphy), stage of the Eocene epoch (geology), Epoch or series (stratigraphy), Series. It spans ...

Lutetian The Lutetian is, in the geologic timescale, a stage (stratigraphy), stage or age (geology), age in the Eocene. It spans the time between . The Lutetian is preceded by the Ypresian and is followed by the Bartonian. Together with the Bartonian it ...

species. ''Hiodon woodruffi'' was described from fossils found in the

Klondike Mountain Formation The Klondike Mountain Formation is an Early Eocene (Ypresian) geological formation located in the northeast central area of Washington (state), Washington state. The formation is composed of volcanic rocks in the upper unit and volcanic plus lacu ...

, Washington and Horsefly shale, British Columbia. Further finds have increased the known paleogeographic range to include the Kishenehn Formation of northwestern Montana. *?†''

Hiodon shuyangensis Hiodontidae, commonly called mooneyes, is a family of ray-finned fish with a single included genus ''Hiodon''. The genus comprise two extant species native to North America and three to five extinct species recorded from Paleocene to Eocene age ...

'' Shen, 1989

References

* {{Authority control Hiodontidae Fish of North America es:Hiodontidae fr:Hiodontidae gl:Hiodóntidos it:Hiodontidae hu:Hiodontidae