This essay SNAKES has a total of 1583 words and 16 pages.
Have you ever wondered exactly what a snake is?
Snakes are elongated, limbless reptiles that have often appeared in
art and mythology. Scientists have currently discovered an estimated
2,500-3,000 living species of snakes living throughout the world except in
the arctic regions. There is one exception to the old world viper, which has
been found as far north as Scandinavia (60° North Latitude).
The size variation of snakes ranges from slender blind snakes
(family Leptotyphlopidae) which reaches a maximum length of 13cm
(5 in.), to the largest snake on record, the Asiatic reticulated python,
which attained a record length of 10m (33 ft).
Have you ever asked anyone what the phyical characteristics of a
snake is? To answer your question: Snakes lack limbs, a sternum (breast
bone), shoulder girdle, exterior ear openings, and urinary bladder, and
most snakes (but not all) lack a pelvic girdle.
There are two types of snakes: constrictors and poisonous.
Constrictors will either stalk their prey or lay very still until Its prey come
near it. It will then strike forward and wrap around the prey crushing it and
cutting off all air supply. The initial strike takes less than one-half second.
It will then swallow the prey animal head first because the hair of animals
folds backwards and makes it easier to swallow.
Poisonous snakes inject a very potent venom into their prey
through fangs. There are three different class of venomous snakes:
Opisthoglyphus (rear fanged), Proteroglyph (front fanged, with holes
pointing outward for "spraying") and Solenoglyph (front fanged and
carved). The most common of these three are Solenoglyphs, which have
fangs that can be folded along the roof of the mouth.
All snakes have powerful digestive enzymes to breakdown the
hair, bones, and other parts of their preys\' body. As part of the digestive
system the salivary glands also produce powerful enzymes. If saliva
containing these enzymes enters the wounds of a prey animal, it not only
starts the digestive process, but also may cause such serous tissue damage
that the prey dies.
The destructive substances in a snakes venom include neurotoxins
and hemotoxins. Neurotoxins paralyze the central nervous system and
cause heart and respiratory failure; hemotoxins destroy blood vessels and
blood cells and cause internal hemorragins. The different substances are
not uniformly present in all snake venom, but vary with the species and
the individual snakes within a species. Venom retains digestive powers;
injected into a prey animal it may shorten the usual days-long digestive
process of a snake by more than half.
Less than one-third of the 2,500-3,000 living species of snakes are
classified as venomous, and less than 300 species are fatal to humans. In
the United States, more than twice as many people are killed by bees,
wasps, and scorpion stings as by snake bites.
There are four basic kinds of snake movement: Lateral (horizontal)
undulation, conceltina movement sidewinding and rectilinear. Lateral
undulating, also called serpentine movement is the most common form
and is used by all snakes. By alternately contracting and relaxing muscles
down each side of the body, the snake forms itself into a number of
rearward-moving horizontal waves. While doing so, the snake maneuvers
its body so that the rear of each backward moving wave pushes against
In concertania movement, also called earthworm movement, the
snake anchors the forepart of its body and pulls the rest of its body behind
it in the form of hoizontal curves; it then extends out the forepart of its
body, anchors it, and repeats the process.
Sidewinding is employed on soft sand or other surfaces that offer
no resistance or slip. In sidewinding the snake loops its body into an
S-shape, with only two points of its body coming in contact with the
surface of the ground. It then progressively shifts the two contact points
back along the body consequently propelling its body forward.
Rectilinear, or caterpillar, movement involves a sliding of the skin
back and forth over the body musculature and is therefor possible only in
those kinds of snakes, such as rattlesnakes and boas, which do not have
the skin tightly attached to the underlying musculature. The ribs remain
essentially motionless, and the scales only provide body-to-ground
The vast majority of snakes lay
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