Fish
Longnose Gar
Lepisosteus osseus · also called longnose gar
The longnose gar looks like it swam straight out of deep time — a long, spear-shaped snout lined with needle teeth, and scales so hard they were once used as arrowheads. It can gulp air at the surface, letting it survive in water that would suffocate almost any other fish.
Overview
Longnose gar live in freshwater and brackish rivers, lakes, and swamps of eastern and central North America. Typically 0.9–1.2 m, they have a distinctive long, needle-toothed snout and thick diamond-shaped armour scales, ambushing other fish with a sideways snap of the jaws.
A living fossil that breathes air
Gars have changed little in 100 million years. A vascularised swim bladder lets them gulp air at the surface, surviving in warm, low-oxygen water that would kill most fish.
Toxic eggs
Longnose gar eggs contain a toxin harmful to mammals and birds, likely an evolved defence protecting the eggs from predation.
Status
The longnose gar is Least Concern, widespread and generally stable, though locally reduced in some altered waterways.
Longnose Gar: common questions
How did the longnose gar get its name and why does its snout look that way?
The name refers directly to its most obvious feature, an unusually long, narrow, beak-like snout that is far more elongated relative to head size than in any of its gar relatives, giving the whole head a distinctive spear-like shape. This long jaw is densely lined with sharp, needle-like teeth and functions as an effective sideways-snapping ambush weapon, since the gar typically hunts by drifting slowly and almost motionlessly close to a school of smaller fish, resembling a floating stick or log, before suddenly swinging its head sideways to grab prey rather than lunging forward the way many predatory fish do.
How is the longnose gar able to breathe air?
Like other members of the gar family, it has a highly vascularised, gas-bladder organ connected to its esophagus that functions much like a primitive lung, allowing the fish to gulp air directly at the water's surface and absorb oxygen from it. This ability lets longnose gar survive comfortably in warm, stagnant, or oxygen-poor water, such as sluggish backwaters and swamps during hot summer months, where most other fish would struggle or die from low dissolved oxygen. Gar rise to the surface periodically to gulp air even in well-oxygenated water, and this behaviour is one of the most reliable ways to spot one from a distance.
Why is the longnose gar considered a living fossil?
Fossils of gars and their close relatives date back roughly 100 million years, and living species today retain a body plan, scale structure, and set of primitive features, including the air-breathing swim bladder and thick ganoid scales, remarkably similar to those ancient forms, indicating the group has changed comparatively little while surrounding fish lineages diversified dramatically. This slow rate of change does not mean the species is primitive or poorly adapted, since gars remain highly effective ambush predators today, but it does make them a valuable living reference point for scientists studying the early evolution of ray-finned fishes.
Are longnose gar eggs really poisonous?
Yes, the eggs of the longnose gar, along with those of several other gar species, contain a toxin that is harmful if ingested by mammals, birds, and even other species of fish, and there are documented cases of pets, chickens, and other animals becoming ill or dying after eating gar roe. Humans are strongly advised never to eat gar eggs for the same reason, even though the flesh of the adult fish itself is edible and consumed in some regions. The toxin is thought to have evolved as a defence that discourages predators from eating the eggs, improving the odds that at least some survive to hatch.