There are more than 34,000 different species of spiders
worldwide. However, there are only a few dozen spiders that
cause fairly pronounced envenomations in human beings. All
spiders are poisonous. However, all cannot pierce the skin,
and all do not have significant amounts of venom that cause
skin lesions or systemic illness in humans. Spiders have long
been a major cause of fears and phobias. The media has not
done the spider population any favors, and have always portrayed
them as evil creatures, dating back to the early days of film.
It is somewhat surprising that something so small can cause
such great fear. However, when one looks at an arthropod with
eight eyes and eight legs that can also run very fast, one
can easily understand how fears and phobias can develop.
Many spiders are capable of wind-blown disbursal. This is
called ballooning. It gives us some understand how spiders
have been found on even isolated islands.
The anatomy of an arthropod is segmented into two body parts,
the cephalothorax, which is the head and the upper torso,
and the abdomen. They have eight legs and the pedipalp, frequently
mistaken for fangs, is actually used to hold prey. Fangs are
usually tucked in, and therefore difficult to see.
Detailed Spider Information