Nature Bulletin No. 209-A December 4, 1965
Forest Preserve District of Cook County
Seymour Simon, President
Roland F. Eisenbeis, Supt. of Conservation
The Alligator Gar, found in the Mississippi River and other streams
emptying into the Gulf of Mexico, probably reaches larger sizes than
any freshwater fish living today. David Starr Jordan, an outstanding
student of fishes in this country, recorded about 60 years ago that this
fish may reach a length of 20 feet and weigh a ton. Less than 10 years
ago, an alligator gar about that size was seen at close range by a
number of people, on several occasions, in the Mississippi River near
Cape Girardeau, Missouri.
The gars are slender primitive fishes, living links between the sharks
and our common bony fishes. They are found only in streams and
lakes of North America. Four living kinds are known. The alligator
gar has a short broad bill armed with a double row of large teeth. The
other three species, which have longer beaks and a single row of long
sharp teeth, are the Long-nosed Gar, the Spotted Gar, and the Short-
nosed Gar. The first of these may reach 25 pounds in weight; the other
two only 5 pounds.
All gars are predators feeding almost exclusively on other smaller fish.
These are taken by a stealthy submarine-like approach, with only the
tips of the fins moving, followed by a quick sideswipe of the long
toothy jaws. The prey is then turned and swallowed, headfirst, at a
Gar eggs are attached to weeds or underwater trash, hatching in the
same places and at the same time as our more abundant minnows, on
which they feed from the very first. The newly hatched gars are about
an inch long and slender as a toothpick. They look much like their
parents except that they have a long vibrating filament on the end of
the tail. They soon lose this but with it the young gars glide through
the water as if driven by a miniature propeller.
Unlike most other fish, in which the air-bladder is a simple
parchment-like sac, gars have air-bladders which serve as efficient
lungs to supplement their gills in aerating their blood. These air-
bladders are spongy, richly supplied with blood vessels, and have a
connection with the throat through which air is exhaled and inhaled
when they come to the top of the water and "break" the surface, as they
frequently do. As a result, gars can survive in water so poor in
dissolved oxygen that other fishes die of suffocation. On the other
hand, gars have such small gills that they often smother to death in
summer if held beneath the surface in nets.
Instead of scales or leathery skin, as in most of our other native fishes,
gars are completely enclosed in a shell or armor of thick bony plates,
so hard that they scarcely can be penetrated by fish spears. It is
reported that in early days the Caribbean Indians used the skins of
alligator gars to make breastplates and cover their shields.
Like sturgeon, the flesh of gars is good when smoked in their shells
and, in the south, the flesh is used to make a kind of fish sausage. The
eggs look enough like sturgeon eggs so that people are often tempted
to make gar caviar. However, they are rank poison. A little bit can
make a grown man deathly sick.
our viewpoint, gars may seem useless and destructive but this
may be their virtue. They help reduce the numbers of young fish
spawned in countless millions by other kinds. In fresh water, they take
the place of the sharks in the high seas.
The gar is the fisherman's friend.
To return to the Nature Bulletins Click Here!
Update: June 2012