Shortnose gar

The shortnose gar (Lepisosteus platostomus) is a primitive freshwater fish of the family Lepisosteidae. It is native to the United States where its range includes the Mississippi and Missouri River basins, ranging from Montana to the west and the Ohio River to the east, southwards to the Gulf Coast. It inhabits calm waters in large rivers and their backwaters, as well as oxbow lakes and large pools. It is a long, slender fish, brown or olive green above and whitish below. It typically grows to about 60 cm (24 in) and is armored by rows of interlocking, rhomboidal ganoid scales.

The shortnose gar is an ambush predator, feeding mostly on fish, but also consuming crustaceans, insects, and other invertebrates. Breeding takes place in spring when females, often accompanied by several males, attach their eggs to clumps of submerged vegetation. The eggs, which are toxic to man, hatch after a week or so. After consuming their yolk sac, the young fish feed on insect larvae and small crustaceans, maturing at an age of about three years.

Habitat

Shortnose gar generally inhabit calm waters in large rivers and their backwaters, as well as oxbow lakes and large, quiet pools, typically around vegetation or downed logs. Gar have the ability to survive in environments with very little oxygen and especially turbid conditions because of their specialized gas bladder. Gar gas bladders have the ability to function like a lung to extract and use oxygen from swallowed air in addition to regulating buoyancy.

Distribution

Shortnose gar today are only located in North America. Located mainly in the central United States, they occupy much of the Mississippi and Missouri River basins ranging from Montana (in the west) to the Ohio River (in the east) in the north and the Gulf Coast from Louisiana and Alabama to parts of Texas in the south.

Behaviour

Shortnose gar are efficient, fierce, ambush predators. They feed mainly on fish, but they are very opportunistic and also eat crayfish, insects, and other invertebrates. During seasonal flooding, Shortnose gar have been observed exploiting newly accessible floodplains to reach terrestrial prey, such as insects and amphibians, thereby broadening their dietary opportunities. Despite feeding mainly on whatever fish are available, Shortnose gar eat more invertebrates than any other gar and have even been found to exhibit territorial defense behaviors around favorable pools while foraging on high numbers of periodical cicadas.