Esociformes is a small order of ray-finned fish

Actinopterygii

The Actinopterygii or ray-finned fishes constitute a class or sub-class of the bony fishes.The ray-finned fishes are so called because they possess lepidotrichia or "fin rays", their fins being webs of skin supported by bony or horny spines , as opposed to the fleshy, lobed fins that characterize...

, with two families, the Umbridae (mudminnows) and the Esocidae (pikes). The pikes of genus Esox

Esox

Esox is a genus of freshwater fish, the only living genus in the family Esocidae — the esocids which were endemic to North America, Europe and Eurasia during the Paleogene through present.The type species is E. lucius, the northern pike...

give the order its name. There are ten species — five in each family.

This order is closely related to the Salmoniformes, the two comprising the superorder Protacanthopterygii

Protacanthopterygii

Protacanthopterygii is a ray-finned fish taxon ranked as a superorder of the infraclass Teleostei. They inhabit both marine and freshwater habitat...

, and are often included in their order. The esociform fishes first appeared in the mid-Cretaceous

Cretaceous

The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...

 — early products of the Euteleost radiation of that time. Today they are found only in fresh water in North America

North America

North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

 and the northern Eurasia

Eurasia

Eurasia is a continent or supercontinent comprising the traditional continents of Europe and Asia ; covering about 52,990,000 km2 or about 10.6% of the Earth's surface located primarily in the eastern and northern hemispheres...

n regions.

Pikes

The pikes tend to be lie-in-wait, ambush predators, with elongated snouts, long, well-muscled torsos, forked tails, and dorsal and anal fins set well back and opposite each other for rapid acceleration along a straight line, allowing the fish to quickly emerge from cover to capture its prey. Prey capture is facilitated by the impaling of the prey animal on the sharp teeth, after which the pike retreats to cover, turns the prey around, and swallows it, head first.

Anatomically, the pikes are characterized by the presence of shark-like, maxillary teeth, a mesocoracoid, and the absence of an adipose fin, breeding tubercules, and pyloric cecae.

The two more prominent species of Esocidae are Esox lucius, or the northern pike

Northern Pike

The northern pike , is a species of carnivorous fish of the genus Esox...

, a popular sport fish that may reach lengths as great as a meter and a half, and the "muskie," E. masquinongy, which grows even larger.

Mudminnows

Mudminnows are much smaller than their pike cousins, with usual lengths of less than 20 cm. However, they are also extremely efficient, lie-in-wait, ambush predators, feeding mostly on the sorts of invertebrates commonly found in warm backwaters. Of the three North American species of genus Umbra, one, U. limi, possesses a limited capability for air breathing. Umbra spp. are most commonly found in the Atlantic coast regions of North America, along the marshy, low-oxygen areas of the Mississippi River, and in similar environments in Europe.