Shortnose gar

Shortnose Gar
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Lepisosteiformes
Family: Lepisosteidae
Genus: Lepisosteus
Species: L. platostomus
Binomial name
Lepisosteus platostomus
Rafinesque, 1820

The Shortnose Gar (Lepisosteus platostomus) is a primitive freshwater fish of the family Lepisosteidae.

Shortnose gar have a prehistoric looking appearance. Like many other "lie-in-wait" predators, gars have an elongated, torpedo-like body with an elongated head containing one row of sharp, conical teeth. Similar to many Paleozoic and Mesozoic actinopterygians, their body is covered in rows of interlocking, rhomboidal ganoid scales that create an exceptionally protective, yet flexible armor around the fish.[1] The dorsal fin is located posterior nearly directly above the anal fin and very near the large caudal fin. Shortnose gars vary in color, changing from brown/olive green on the dorsal surface to yellow on the sides and white on the underbelly. Shortnose gar can be discerned from other gar species in that they lack the upper jaw of the alligator gar, the long snout of the longnose gar, and the markings of the spotted gar.[2]

Contents

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 drowned logs.[3] Gars have the ability to survive in environments with very little oxygen and especially turbid conditions thanks to a specialized gas bladder. Gar gas bladders have the ability to function like a lung to extract and utilize oxygen from swallowed air in addition to regulating buoyancy.[2]

Reproduction/Life Cycle

Shortnose gar typically spawn in the spring during April, May and June when water temperatures are near the mid-60's. Often accompanied by more than one male, females scatter large, yellowish-green eggs in quiet, shallow water among submerged vegetation or other underwater structures. A sticky adhesive holds the eggs together in clumps where they hatch after eight to nine days.[2] The eggs are poisonous to birds and mammals, including humans.[3] The young remain in the yolk sac for another week where they feed on insect larvae and small crustaceans. Young gars typically lead solitary lives and sexual maturity is achieved around three years of age when the gar reaches approximately 15 inches in length.[2]

Diet Habits

Shortnose gar are efficient, fierce ambush predators. They feed mainly on fish, but they are very opportunistic and will also eat crayfish, insects, and other invertebrates.[3] 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.[4]

Range/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.[5]

Importance to Humans

Shortnose gar help maintain ecosystem equilibrium by feeding on minnows that are destructive to game fish and other fish populations. Shortnose gar are popular aquarium fish, and are frequently found in public aquariums across the country.

Conservation Status

With very few natural predators able to cope with a gar's thick ganoid armor, shortnose gars are generally plentiful. The only exception is in the state of Montana, where they are considered a fish of special concern due to restricted distribution and limited population sizes.[2]

Etymology of Name

In Greek, Lepisosteus translates to "bony scale," and platostomus translates to "broad mouth."[1]

Trivia

The longest Shortnose gar was measured at 34.64 inches. [5]

References

  1. ^ a b [1], Short-nosed Gar - zen gyotaku.
  2. ^ a b c d e Shortnose Gar - Montana Field Guide.
  3. ^ a b c [2], Short-nosed Gar - Warner Nature Center.
  4. ^ [3], American Midland Naturalist Journal: Shortnose Gar - Territorial Defense of Profitable Pool Positions.
  5. ^ a b Lepisosteus platostomus, Fishbase.

Froese, Rainer, and Daniel Pauly, eds. (2011). "Lepisosteus platostomus" in FishBase. April 2011 version.

"Lepisosteus platostomus". Integrated Taxonomic Information System. http://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=161096. 

Spitzer, Mark. Season of the Gar: Adventures in Pursuit of America's Most Misunderstood Fish. U of Arkansas Press, 2010.