Gar
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Gar
Scientific classification
Kingdom: Animalia Phylum: Chordata Class: Actinopterygii Order: Lepisosteiformes Family: Lepisosteidae
Species
Atractosteus spatula Atractosteus tristoechus Atractosteus tropicus Lepisosteus oculatus Lepisosteus osseus Lepisosteus platostomus Lepisosteus platyrhincus

In American English the name gar (or garpike) is strictly applied to members of the Lepisosteus, a family including seven living species of fish in two genera that inhabit fresh, brackish, and occasionally marine, waters of eastern North America, Central America, and the Caribbean islands.^[1][2]

Etymology

In British English the name gar was originally used for a species of needlefish, Belone belone, found in the North Atlantic, itself likely named after the Old English word gar meaning "spear".^[3] Belone belone is now more commonly referred to as the "garpike" or "gar fish" to avoid confusion with the North American gars of the family Lepisosteidae.^[4]

The genus name Lepisosteus comes from the Greek lepis meaning "scale" and osteon meaning "bone".^[5] Atractosteus is similarly derived from Greek, in this case from atraktos, meaning "arrow".^[6]

Distribution

The gars are members of the Lepisosteiformes (or Semionotiformes), an ancient order of "primitive" ray-finned fish; fossil gars are known from the Permian onwards. Their primitive traits are their very hard armour-like ganoid scales, a swimming bladder open to the pharynx that can function as a lung and the heterocercal tail. Fossil gars are found in both Europe and North America, indicating that in times past these fish had a wider distribution than they do today. Gars are considered to be a remnant of a group of rather primitive bony fish that flourished in the Mesozoic, and are most closely related to the bowfin, another archaic fish now found only in North America.

Anatomy and morphology

Large gar at the Shedd Aquarium

Gar bodies are elongated, heavily armored with ganoid scales, and fronted by similarly elongated jaws filled with long sharp teeth. Tails are heterocercal, and the dorsal fins are close to the tail. As their vascularised swim bladders can function as lungs, most gar surface periodically to take a gulp of air, doing so more frequently in stagnant or warm water when the concentration of oxygen in the water is low. As a result, they are extremely hardy and able to tolerate conditions that would kill most other fish.

All the gars are relatively big fish, but the alligator gar Atractosteus spatula is the champion, as specimens having been recorded up to 3 meters in length.^[7] Even the smaller species, such as Lepisosteus oculatus, are large, commonly reaching lengths of over 60 cm (2 feet), and sometimes much more.^[8]

Ecology

Gar tend to be slow moving fish except when striking at their prey. They prefer the shallow and weedy areas of rivers, lakes, and bayous often congregating in small groups.^[9] They are voracious predators, catching their prey with their needle-like teeth, obtaining with a sideways strike of the head.^[10] Gar feed extensively on smaller fish and invertebrates such as crabs.^[11] Gar are found across eastern North America from Costa Rica to southern Quebec (for example Lepisosteus osseus).^[12] Although gar are primarily found in freshwater habitats several species enter brackish waters and a few, most notably Atractosteus tristoechus, are sometimes found in the sea.^[13][14]

Significance to humans

Gar flesh is edible, and sometimes available in markets, but unlike the sturgeon that they resemble, their eggs (roe) are poisonous. Several species are traded as aquarium fish.^[15]

Cultural Significance

The Gar fish is of considerable significance to Native American peoples of the southeastern United States where the gar figures prominently in ceremonial life and music. See Creek, Seminole

References

External links

• Family Lepisosteidae entry at FishBase