Species Fact Profile: Alligator Gar (Atractosteus spatula)

Alligator Gar

Atractosteus spatula (Lacepede, 1803)

Range: Southeastern United States (Ohio and Mississippi Rivers)
Habitat: Freshwater and Brackish Lakes, Rivers, Wetlands
Diet: Fish, Carrion, Turtles, Waterfowl
Social Grouping: Asocial
Reproduction: Breed once annually, usually between May and July.  Tens of thousands of eggs are left stuck to rocks and underwater vegetation.  No other parental care is provided.  When the young hatch, they float to the surface of the water.  Sexual maturity may take over ten years to achieve (longer in females than males).
Lifespan: 25-50 Years (Females live longer than males)
Conservation Status: Not Evaluated

• Gray-green or brown on dorsal surface, yellow or white on the ventral surface.  Dorsal surface may have some brown spotting 
• Largest gar species and one of the largest freshwater fishes in North America, growing up to 2.5 meters long and weighing over 130 kilograms.  
• The body is long and torpedo-shaped, the tail is asymmetrical.   The thick, overlapping scales (ganoid scales) resemble chain-mail (Native Americans in the Southeast used these scales for arrowheads and shields).  The snout is long and broad with two rows of gang-like teeth
• The swimbladder serves as a psuedo-lung, allowing the gar to gulp air and breathe in waters with low oxygen levels 
• Named for their similarities to alligators both in terms of appearance and behavior, including floating at the surface of the water, mimicking a log.  They are sit-and-wait predators, relying on camouflage and using short bursts of speed to capture prey that comes within range
• Highly opportunistic, have been seem seizing ducks shot by hunters and attacking duck decoys
• Humans and alligators are the only natural predators of adults. Juveniles may be taken by larger fish, turtles, and other aquatic predators; the bright red eggs are poisonous to discourage predation
• Considered potentially dangerous to humans due to large size and powerful teeth, but no documented cases of attacks have been reported
• In decline due to habitat loss (dredging, damming) and overfishing, protected in many areas.  Have been extirpated in some areas, considered a nuisance by fishermen due to their competition for crab and fish stocks
• Captive rearing is being used to restock wild alligator gar populations, in part to control invasive Asian carps; there are also efforts underway to farm the species for food in Mexico
• Alligator gars have been found in several Asian countries, presumably released individuals from private aquariums