Esocidae is a family of fish in the order

Esociformes The Esociformes () are a small order of ray-finned fish, with two families, Umbridae and Esocidae. The pikes of genus ''Esox'' give the order its name. This order is closely related to the Salmoniformes, the two comprising the superorder Prota ...

, which contains pike, pickerel, and mudminnows. While the family traditionally only contained the genus ''

Esox ''Esox'' is a genus of freshwater fish commonly known as pike or pickerel. It is the type genus of the family Esocidae. The type species of the genus is '' Esox lucius'', the northern pike. ''Esox'' has been present in Laurentia (which lat ...

'', recent genetic and paleontological research have recovered ''

Novumbra ''Novumbra'' is a genus of mudminnows (family Umbridae) native to Oregon and Washington state, USA. Molecular data suggests that this genus is more closely related to ''Esox'' than ''Dallia'' and ''Umbra''. ''Novumbra'' diverged from ''Esox'' rou ...

'' and ''

Dallia ''Dallia'' is a genus of mudminnows native to Russia and Alaska Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on ...

'' as members of the family Esocidae, being closer related to ''Esox'' than ''

Umbra The umbra, penumbra and antumbra are three distinct parts of a shadow, created by any light source after impinging on an opaque object. Assuming no diffraction, for a collimated beam (such as a point source) of light, only the umbra is cast. T ...

''. Fossil specimens from the

Mesozoic The Mesozoic Era ( ), also called the Age of Reptiles, the Age of Conifers, and colloquially as the Age of the Dinosaurs is the second-to-last era of Earth's geological history, lasting from about , comprising the Triassic, Jurassic and Cretace ...

in North America have been assigned as two additional genera in this family.

Distribution

Esocidae has a

holarctic The Holarctic realm is a biogeographic realm that comprises the majority of habitats found throughout the continents in the Northern Hemisphere. It corresponds to the floristic Boreal Kingdom. It includes both the Nearctic zoogeographical reg ...

distribution. Species in the genus ''Esox'' can be found in Eurasia and North America, while ''

'' has a more restricted range in

Alaska Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U ...

and eastern

Siberia Siberia ( ; rus, Сибирь, r=Sibir', p=sʲɪˈbʲirʲ, a=Ru-Сибирь.ogg) is an extensive geographical region, constituting all of North Asia, from the Ural Mountains in the west to the Pacific Ocean in the east. It has been a part ...

. Of extant esocids, ''

'' has the most restricted range of all, being found only on the

Olympic Peninsula The Olympic Peninsula is a large arm of land in western Washington that lies across Puget Sound from Seattle, and contains Olympic National Park. It is bounded on the west by the Pacific Ocean, the north by the Strait of Juan de Fuca, a ...

Washington state Washington (), officially the State of Washington, is a U.S. state, state in the Northwestern United States, Pacific Northwest region of the Western United States. Named for George Washington—the first President of the United States, U.S. p ...

. Fossils of esocids ''Estesesox'' and ''Oldmanesox'' have been recovered in North America. '' Estesesox'' fossils have been described from the

Lance A lance is a spear designed to be used by a mounted warrior or cavalry soldier (lancer). In ancient and medieval warfare, it evolved into the leading weapon in cavalry charges, and was unsuited for throwing or for repeated thrusting, unlike s ...

Hell Creek The Hell Creek Formation is an intensively studied division of mostly Upper Cretaceous and some lower Paleocene rocks in North America, named for exposures studied along Hell Creek, near Jordan, Montana. The formation stretches over portions of ...

, Oldman, Foremost, and Milk River Formations. '' Oldmanesox'' fossils have been described from the Oldman Formation.

Behavior

Despite differing size and mouth shape, all extant species of esocids are sight-based

ambush predators Ambush predators or sit-and-wait predators are carnivorous animals that predation, capture or trapping, trap prey via crypsis, stealth, aggressive mimicry#Luring prey, luring or by (typically instinctive) hunting strategy, strategies utilizing an ...

, taking any animal they can fit in their mouth. Both pike and blackfishes display cannibalistic tendencies. While the

Olympic mudminnow The Olympic mudminnow (''Novumbra hubbsi'') is a fish native to the western lowlands of Washington: the Chehalis River basin, Deschutes River basin, and some Olympic Peninsula basins. It grows to 8 cm (about 3 in) in length, and is Was ...

is aggressively territorial to fish of the same size during the spawning season, it will generally leave its fry alone.

Relationships

Esox is the youngest genus, with ''Dallia'' and ''Novumbra'' branching off farther up the line. The cladogram below has been found by López ''et al.'', with the two additional fossil genera included at the base of the tree. Due to the fragmentary nature of ''Oldmanesox'' and ''Estesesox'', very little information on the exact relationships between the two genera and the rest of the species in the family has been published. More recent genetic studies which place ''Dallia'' and ''Novumbra'' in Esocidae may influence future studies on placement of ''Estesesox'' and ''Oldmanesox'' within the Esocidae and/or Esociformes family trees.

References

Taxa named by Georges Cuvier Ray-finned fish families {{Esociformes-stub