BioKIDS home

Kids' Inquiry of Diverse Species

Gar

Lepisosteus osseus

What do they look like?

Longnose gar have long, narrow snouts more than twice as long as the rest of the head and they have abundant, sharp, villiform teeth. Mature L. osseus are olive brown in color with a white belly. Dark spots can be found on the median fins and, in individuals from clear water, on the body. Young L. osseus have a narrow brown stripe along their back and a broad dark brown strip along their sides (Page and Burr, 1991; Becker, 1983). The dorsal and anal fins of the longnose gar are located far back on the body, which is encased in a heavy armor of interlocking, rhomboid, ganoid scales (Ross, 2001).

  • Range mass
    5 to 18600 g
    0.18 to 655.51 oz
  • Range length
    8 to 1830 mm
    0.31 to 72.05 in
  • Average length
    660-838 mm
    in

Where do they live?

Lepisosteus osseus is widely distributed throughout the eastern United States. L. osseus can be found along the eastern seaboard from the Delaware River, N.J. to central Florida and in the upper Midwest in the St. Lawrence River, Quebec and all of the Great Lakes except Superior. It lives throughout the entire Mississippi River basin and can be found as far south as the Rio Grande drainages of Texas and Mexico (Page and Burr, 1991).

What kind of habitat do they need?

L. osseus live in a variety of lowland habitats, preferring sluggish areas of larger rivers, lakes, reservoirs and estuaries. They can live in brackish water and are common in the deeper bayous along the Gulf Coast (Goodyear, 1967). L. osseus can tolerate high water temperatures and can often be found near the water surface on warm days or nights (Becker, 1983).

  • Aquatic Biomes
  • lakes and ponds
  • rivers and streams
  • coastal

How do they grow?

L. osseus eggs typically hatch 3-9 days after they have been laid and the larvae are approximately 8-10 mm long at hatching (Yeager and Bryant, 1983; Becker, 1983). The yolk sac is absorbed at approximately 12 mm TL and fins form around 30 mm TL (Simon and Wallus, 1989). Early-stage L. osseus larvae (sac-fry) are relatively inactive and possess an adhesive structure at the tip of the snout by which they attach to objects in the water. By 10 to 11 days after hatching, L. osseus are 18-20 mm long. Young longnose gar grow rapidly and studies have shown that they can gain 3.2 mm and 1.8 grams per day, when maintained in aquaria with an unlimited food supply (Riggs and Moore, 1960). Male longnose gar will typically mature at three to four years of age while females do not mature until six years (Ross, 2001).

How do they reproduce?

During the mating process as many as 15 males may approach the female. If she is ready, she will lead them in an elliptical pattern for up to 15 minutes prior to spawning. Once over the spawning bed, the males will nudge the female with the ends of their snouts in the pectoral, lateral, and ventro-lateral areas. During this phase, frequent surfacing and gulping take place. Ultimately, the spawning group will position itself at one place with heads down and snouts very close to the bottom. Rapid and violent quivering follows as the sperm and eggs are released (Haase, 1969).

Spawning occurs in the spring and summer for L. osseus. In rivers, longnose gar make upstream spawning runs during the spring period of high water, then move downstream into larger pools. They have also been seen spawning in open, wind-exposed areas over rocks as well as gravelly, weedy sites. Spawning takes place in shallow water resulting in the backs of the fish sometimes being exposed. Often, more than one male will attend to the larger female during spawning. She will not release all of her eggs at the same time. Once shed, the eggs become very sticky and adhere to solid objects on the substrate (Ross, 2001). Females produce about 30,000 eggs per year; 77,000 eggs were once recorded in a female observed in Tennessee (Etnier and Starnes, 1993).

  • Breeding season
    Spring/Summer
  • Range number of offspring
    4,273 to 77,000
  • Average number of offspring
    30,000
  • Range time to hatching
    3 to 9 days
  • Range age at sexual or reproductive maturity (female)
    3 to 6 years
  • Range age at sexual or reproductive maturity (male)
    3 to 6 years

L. osseus provide no parental care. Research has shown frequent occurrences of the longnose gar laying eggs in smallmouth bass nests, where the male bass guarding the nest provides protection for the young gar in addition to its own young (Goff, 1984).

  • Parental Investment
  • pre-fertilization
    • provisioning

How long do they live?

Longnose gar can be aged by annular marks on their branchiostegal rays. Female L. osseus grow more quickly and live longer than males. They are capable of living well beyond 17 years and some have reached 22 years in the wild. In captivity, female L. osseus have lived up to 30 years (Ross, 2001). Male longnose gar typically do not live longer than 11 years in the wild. A study by Netsch and Witt (1962) in Missouri did not find any males older than 17 years of age.

How do they behave?

A unique behavior of the longnose gar is its ability to survive in low-oxygen waters. L. osseus has a highly vascularized swimbladder, which connects to the pharynx by a pneumatic duct, to breath air. Under normal oxygen levels, both aquatic and aerial respiration occurs. However, as oxygen becomes limited, L. osseus will close its gill covers and can survive indefinitely on aerial respiration alone (McCormack, 1967).

How do they communicate with each other?

The communication of L. osseus is not well understood. They are a gregarious fish though, often found in groups of two to five, sometimes along with shortnose gar (Lepisosteus platyrhincus) (Holloway, 1954).

What do they eat?

By 10-11 days after hatching, young gar begin feeding on small crustaceans, such as cladocerans and copepods, and insects, including various dipterans such as chironomids. L. osseus quickly switch to a diet of primarily fish. Gars are active night feeders and much of the feeding is surface-oriented (Becker, 1983). They catch their prey sideways in their well-toothed jaws by lying motionless or slowly stalking prey until the smaller fish are within reach. L. osseus slashes its beak from side to side, impaling the prey on its teeth. The prey is then maneuvered into position to be swallowed headfirst (Branson, 1966).

In most studies of adult L. osseus, a variety of species made up a majority of the diet, with the dominant prey changing among locations. Inland silversides were particularly common prey of juvenile gar in Lake Texoma, making up 84% of the diet, with gamefishes accounting for less than 1% of the diet (Eschelle, 1968). In Florida, the diet was comprised mainly of fishes, with gizzard shad, bullhead catfish, and small bluegill particularly common (Crumpton, 1971). In Missouri, Netsch (1964) found that fishes made up 98% of the diet with shiners being the most common prey. In some lakes, adult longnose gar may consume large numbers of sunfishes. Menhaden are a major food source along coasts where L. osseus move towards the mouth of bayous into higher salinity waters in the afternoon and evening to find this more prevalent prey. Longnose gar will then move back up the bayous, into the lower salinity waters in the morning (Ross, 2001).

  • Animal Foods
  • fish
  • eggs
  • insects

What eats them and how do they avoid being eaten?

As previously mentioned, L. osseus are encased in a heavy armor of interlocking, rhomboid, ganoid scales. The ganoid scales are composed of two layers, an outer layer of ganoin and an inner layer of isopedine, both of which are penetrated by blood vessels. As a result of this armor, the longnose gar has no major predators. There have been occurrences of longnose gars being attacked by alligators, but research suggests that these may have been opportunistic events (McCormack, 1967).

  • Known Predators
    • American alligators (Alligator mississipiensis)

What roles do they have in the ecosystem?

The general perception of L. osseus is that it is a nuisance or “trash” fish. However, all species of gar serve as hosts to the parasitic young (glochidia) of the yellow sandshell, a freshwater mussel. Without gar, this mussel would disappear unless it was maintained by artificial means (Becker, 1983).

Do they cause problems?

L. osseus have historically been perceived as detrimental to game species, such that gar management has emphasized removing the species from aquatic environments (Johnson and Nolte, 1997). In addition, the longnose gar has a propensity for becoming entangled in nets and is considered a pest by commercial fisherman (Ross, 2001). Forbes and Richardson (1920) stated: “it is a wholly worthless and destructive nuisance in relation to mankind. It has, in fact, all the vices and none of the virtues of a predaceous fish” (Netsch and Witt, 1962).

How do they interact with us?

L. osseus, although palatable, are not particularly popular or sought after by anglers. There is a commercial fishery for longnose gar in Arkansas though (Ross, 2001). Consideration has been given to gars as a possible aid in controlling overpopulation of sunfish and yellow perch as well (Niemuth et al., 1959). Additionally, gar skins have been used to a small extent for covering picture frames, purses, and the like. The gar scales are very hard and take on a fine polish (Forbes & Richardson, 1920).

  • Ways that people benefit from these animals:
  • pet trade
  • food
  • controls pest population

Are they endangered?

L. osseus is not listed on the IUCN list, the United States Endangered Species Act list or the CITES appendices.

Some more information...

The large, greenish eggs of L. osseus are toxic to humans, other mammals and birds and should not be eaten (Netsch and Witt, 1962). Historically, the heavy rhomboid scales of the gar were often used by local Indians for arrow points, ornaments, and other instruments (Suttkus, 1963).

Contributors

William Fink (editor), University of Michigan-Ann Arbor.

Bruce Rudy (author), University of Michigan-Ann Arbor.

References

Becker, G. 1983. Fishes of Wisconsin. Madison: University of Wisconsin Press.

Branson, B. 1966. The gar, a plea for a heritage of past. Kentucky Happy Hunting Ground,, 22 (July): 16-19.

Crumpton, J. 1971. Food habits of longnose gar (*Lepisosteus osseus*) and Florida gar (*Lepisosteus plaryhincus*) collected from five central Florida lakes. Proceedings of the Annual Conference of the Southeastern Association of Game and Fish Commissioners,, 24 (1970): 419-424.

Eschelle, A. 1968. Food habits of young-of-year longnose gar in Lake Texoma, Oklahoma. The Southwestern Naturalist,, 13: 45-50.

Etnier, D., W. Starnes. 1993. The Fishes of Tennessee. Knoxville: The University of Tennessee Press.

Forbes, S., R. Richardson. 1920. The Fishes of Illinois. Urbana: Illinois Natural History Survey.

Goff, G. 1984. Brood care of the longnose gar (*Lepisosteus osseus*) by smallmouth bass (*Micropterus dolomieui*). Copeia,, 1984: 149-152.

Goodyear, C. 1967. Feeding habits of three species of gars, *Lepisosteus*, along the Mississippi Gulf Coast. Transactions of the American Fisheries Society,, 96: 296-300.

Haase, B. 1969. An ecological life history of the longnose gar, *Lepisosteus osseus* (Linnaeus), in Lake Mendota and several other lakes of southern Wisconsin. Madison: Doctoral dissertation. University of Wisconsin.

Holloway, A. 1954. Notes on the life history and management of the shortnose and longnose gars in Florida waters. Journal of Wildlife Management,, 18(4): 438-449.

Johnson, B., D. Noltie. 1997. Demography, growth, and reproductive allocation in stream-spawning longnose gar. Transactions of the American Fisheries Society,, 1216: 438-466.

McCormack, B. 1967. Aerial respiration in the Florida spotted gar. Quarterly Journal of the Florida Academy of Science,, 30(1): 68-72.

Netsch, N. 1964. Foods and feeding habits of longnose gar in central Missouri. Proceedings of the Annual Conference of the Southeastern Association of Game and Fish Commissioners,, 18: 506-511.

Netsch, N., A. Witt Jr. 1962. Contributions to the life history of the longnose gar (*Lepisosteus osseus*) in Missouri. Transactions of the American Fisheries Society,, 91(3): 251-262.

Niemuth, W., W. Helm, V. Hacker. 1959. Life history, ecology and management of the longnose gar. Madison, Wisconsin: Report to the Conservation Division, Wisconsin Department of Natural Resources.

Page, L., B. Burr. 1991. Peterson Field Guide to Freshwater Fishes. Boston: Houghton Mifflin Company.

Riggs, C., G. Moore. 1960. Growth of young gar (*Lepisosteus*) in aquaria. Proceedings of the Oklahoma Academy of Science,, 40: 44-46.

Ross, S. 2001. The Inland Fishes of Mississippi. Jackson: University Press of Mississippi.

Simon, T., R. Wallus. 1989. Contributions to the early life histories of gar (*Actinopterygii: Lepisosteidae*) in the Ohio and Tennessee river basins with emphasis on larval development. Transactions of the Kentucky Academy of Science,, 50: 59-74.

Suttkus, R. 1963. Order Lepisostei. Sears Foundation for Marine Research,: 61-88.

Yeager, B., R. Bryant. 1983. Larvae of the longnose gar, *Lepisosteus osseus*, from the Little River in Tennessee. Journal of the Tennessee Academy of Science,, 58: 20-22.

 
University of Michigan Museum of ZoologyNational Science Foundation

BioKIDS home  |  Questions?  |  Animal Diversity Web  |  Cybertracker Tools

Rudy, B. 2003. "Lepisosteus osseus" (On-line), Animal Diversity Web. Accessed July 24, 2014 at http://www.biokids.umich.edu/accounts/Lepisosteus_osseus/

BioKIDS is sponsored in part by the Interagency Education Research Initiative. It is a partnership of the University of Michigan School of Education, University of Michigan Museum of Zoology, and the Detroit Public Schools. This material is based upon work supported by the National Science Foundation under Grant DRL-0628151.
Copyright © 2002-2014, The Regents of the University of Michigan. All rights reserved.

University of Michigan