Spiders
This report deals with testing the toxicity of
certain chemicals on
spiders, and determining the toxicity by how it affects
it’s ability to weave
it’s web. This report contains research on the four
chemicals (benzedrine,
chloral hydrate, caffeine, and alcohol) as wellas the
spiders and their webs.
Spiders are of course found in the class
Arachnidia, which also contain mites,
scorpions, and other arthropods. The
order which spiders are classified under is
called Araneae, a word of Latin
origin. Most spiders are land dwelling, but some
can be aquatic. Those that
are aquatic spend most of their lives in or around
water. Spiders can live in
a vast amount of different places around the world.
Jumping spiders have
been collected on Mt. Everest at a height of 22,000 feet,
the highest
elevation at which any animal has been collected (Orkin, Insect Zoo
1).
Adult species vary greatly in size, which is a contributing factor in
the
prey they choose, and also the way they catch this prey. Spiders range
from less
than three hundredths of an inch to more than 10 inches. All
spiders are
carnivorous in their eating habits, insects being first on their
menu. Spiders
usually catch live animals because the movement of the prey
attracts its
attention. Some spiders have poor vision, and rather depend on
the movement of
it’s web to locate an insect. (Orkin, Insect Zoo 2). The prey
is usually
wrapped in silk before the spider injects the venom to kill it.
Yet the larger
the spiders, the larger its prey. Some spiders have been known
to kill
vertebrate animals, such as fishing spiders, who thrive on small
fish, or bird
spiders, feeding on small birds from South America, as well as
a variety of
lizards. Some species have even been known to attack snakes.
When food is
scarce, mainly during winter months, spiders have no trouble
have no trouble
with food, most can go months without eating. A spider’s
structure is
irregular when compared to other animals, yet similar to those
of other
arachnids. An arachnid is of course classified on the number of it’s
legs,
which happens to be eight. Spiders have two main body regions: the
cephalothorax
and the abdomen . The cephalothorax consists of the head and
the thorax, which
are fused together. Insects have three main body regions, a
head, thorax, and
abdomen. Other arachnids have those two regions connected
through a broad waist.
All spiders also have simple eyes, lacking
compound eyes only found in insects.
Spiders can have many pairs of eyes
however, this number often reaches four.
Spiders do not have an antenna
either. (Orkin, Insect Zoo 6) Many spiders
secrete a fluid in their posterior
abdomens which is later extruded as a silk.
This fibrous protein is used
to weave webs, snares, shelters, and/or egg sacs. A
spider uses fingerlike
spinnerets to disperse this silk. Most spin more than one
kind of silk to
customize its web, or to just fit its purpose. For example, the
spider makes
some parts of its web not sticky so that it can run across it and
not get
caught. Another source says that spiders first lay down a type of silk
known
as "dry thread", with which they weave a "dry spiral. Once this is
completed,
the spider lays down a sticky spiral of thread and goes on to eat the
dry
one. The sticky spiral must be replaced every couple days because it
loses
its "stickiness." Some scientists suggest that the pattern of an orb
web
(most common type of web used by spiders) is designed to attracted
insects.
These webs are thought to produce patterns that resemble those
reflected by
numerous flowers in UV light. Since insects only see in UV
light, they might as
well fly into a trap (Lyons, Spider Silk 1). Spider silk
has been recognized for
centuries as a high quality fiber. A few pairs of
stockings and gloves have been
made from the silk as early as the 16th
century. Various attempts have been made
to produce it commercially, yet have
failed. New efforts are currently under
construction as more people are
finding new ways to use a strong, elastic fiber.
A few of these ideas are
bulletproof vests, or replacement tissues for tendons
and ligaments. Advanced
techniques, such as molecular biology are being used to
determine the exact
composition of spider silk, and the changes it undergoes as
the liquid
proteins inside the spider become the actual silk itself (Lyons,
Spider
Silk 1). Moving on, chloral hydrate (one of the substances being used in
the
experiment)is the oldest of hypnotic, sleep inducing depressants.
This
organic chemical was first synthesized in 1832 (DEA, Chloral Hydrate 1).
Chloral
hydrate takes about 30 minutes to take effect, and should induce
sleep within an
hour. Chloral hydrate will not affect respiration and blood
pressure when taken
at the recommended doses, yet larger dosage can lead to
severe respiratory
depression and extremely low blood pressure. It may also
irritate mucous
membranes as well as the skin (Versaware Inc., Chloral
Hydrate 1). Chloral
hydrate is still being relied on by many to this day, yet
its use declined with
the introduction of barbiturates. The next drug,
benzedrine, is also known as
speed. The drug can takes various forms,
including tablets, pills and capsules.
In this case for the experiment,
the drug will take the form of powder.
Benzedrine can be taken orally,
injected, or inhaled, and its effects can be
severe, if not fatal. Benzedrine
is a stimulant, therefore causing increased
heart and respiratory rates,
elevated blood pressure, dilated pupils, decreased
appetite, sweating,
headaches, blurred vision, dizziness, sleeplessness,
anxiety, restlessness,
and moodiness. High doses or injections have the
potential to cause a rapid
or irregular heartbeat, tremors, loss of
coordination, physical collapse,
sudden increase in blood pressure, very high
fever, and possibly heart
failure. Alcohol, on the other hand, is a depressant.
This drug slows the
nervous system, and requires no ingestion. Once in the body,
it enters the
bloodstream, and passes through the stomach lining. Alcohol passes
through
the three main areas of the brain via the bloodstream. The frontal
lobe,
which controls judgment and reasoning, the midbrain, which regulates
muscle
control and coordinates movement, and the hindbrain, which controls
bodily
functions such as respiratory rate and heart rate, can all be
affected. Death
can result from a BAC (blood alcohol content) of 0.5 or
higher. (Schroeder,
Alcohol Awareness 23) Caffeine is another stimulant
that is widely used
throughout the world. Found in coffee beans, caffeine can
be just as dangerous
as other drugs. Signs of intoxication include
restlessness, nervousness,
excitement, insomnia, flushed face, diuresis,
gastrointestinal disturbance,
muscle twitching, periods on inexhaustibility,
cardiac arrhythmia, and/or
agitation. People have lost their lives to
caffeine, most having ingested more
than 20 grams. Serious intoxication can
lead to delirium, seizures, and
hyperglycemia. Though these statistics are
for humans only, they strongly
correlate to other animals as well, because
their toxicity does not change based
on who the recipient is. Unless spiders
have an unprecedented immune system to
certain chemicals, the results should
be on the same scale as the
human’s
effects.
Bibliography
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http://aomt.netmegs.com/coffee/caffaq.html,
Nov. 7th, 1999 Community
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Awareness/Stimulants.html,
Nov. 7, 1999 DEA. Drugs of Abuse [Online]
Available
http://mir.drugtext.org/druglibrary/schaffer/dea/pubs/abuse/chap3/depress/chloral.htm,
Nov.
7, 1999 Lansing State Journal. How Does a Spider Web Work?.
[Online]
Available htttp://www.pa.msu.edu/~sciencet/ask_st/071697.html,
Nov. 8, 1999
Lyons, Ron. Alcohol Awareness. New York: Anderson
Publishing, 1995 O. Orkin.
Insect Zoo [Online] Available
http://www.naturalpartners.org/InsectZoo/Students/aranea.html,
November
7th, 1999 Versaware Inc. Chloral Hydrate [Online] Available
http://www.funkandwagnalls.com/encyclopedia/low/articles/c/c005000376f.html,
Nov.
6, 1999