Gars
are called living fossils because nearly all their relatives
are extinct. They were abundant in Europe during the Tertiary or the
first period of the Cenozoic but, before the close of that period,
which embraced approximately 58 million years measured by radio-activity,
they became extinct in Europe, and the family is now exclusively North
American in its distribution. .)
Gars
are distinguished by their slender cylindrical bodies, their thin,
long jaws which are produced forward into a beak, and by the more
or less diamond-shaped scales that cover the body. The jaws are
armed with sharp teeth.
Longnose
gar (Lepisosteus osseus) is the accepted common name of the fish
but billfish and gar pike are also used. It has a very elongated
and subcylindrical body, covered with obliquely and regularly arranged
diamond-shaped, hard plates or scales, covered with an enamel-like
substance, ganoin.
The body length attained may be five feet, but the average is much
less. Three-foot specimens are not uncommon. The jaws are elongated
into a beak which is twice the length of the head and provided with
several rows of teeth which are exceptionally strong, sharp and
conical.
Although
extremely variable, the colour is more commonly greenish above,
silvery on the sides and whitish below. The body and fins have large
black spots or blotches, and young individuals have a blackish lateral
band. The skeleton of the fish is partly cartilage and partly bone.
Distribution:
The longnose gar is found in rivers and lakes throughout the eastern
half of the United States, as far north as southern Quebec and extreme
southern Ontario in the Great Lakes and as far south as northern
Mexico. The most concentrated numbers of longnose gars are found
throughout the American Deep South, Texas, Alabama (Cahaba River
system) and anywhere along the Mississippi River. Longnose Gar are
found in warm, shallow water with abundant vegetation.
Habitat:
The longnose gar is found generally in warm, quiet areas of larger
bodies of water. Habitat requirements may have prevented their penetration
into northern rivers and lakes. The waters of the Mississippi Valley
are believed to have been the source of the population of this species.
They may be observed floating like sticks near the surface of the
water on warm days or nights. This is a useful form of mimicry by
means of which they may drift towards their prey. They are sluggish
in their habits except when feeding, when they move swiftly to capture
their prey.
They possess gills but, because of the fact that the air bladder
is connected with the pharynx, it may be used as a lung, and they
can rise to the surface to expel air from the air bladder and take
in a fresh supply. The ability to use atmospheric air in this way
enables the fish to live in waters of low oxygen content.
Spawning:
The longnose gar spawns in late spring or in early summer; they
appear in large schools in a suitable spawning area, in close formation
in order to en-sure fertilization of the eggs. They have polygamous
procreating habits. The spawn is deposited in shallow, weedy- bays,
usually on submerged vegetation or aquatic plant roots.
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