From Alzheimer’s to Zebrafish: Eclectic Science and Regulatory Stories 126
Arachnophobia (fear of spiders) is quite common, and with good reason. In most of
Europe during the Middle Ages, spiders were considered a source of contamination that
absorbed poisons in their environment.
Any food in contact with spiders was deemed unclean, and if a spider fell into water,
that water was held to be poisoned. Spiders were believed to be messengers of the Black
Plague and death.1 Fear of spiders has a long history. Around the time of the birth of
Christ, parts of Abyssinia (now Ethiopia) were abandoned by the whole population as a
result of a plague of spiders.2
Spiders rank with snakes, cockroaches and rats on the list of most disliked crea-
tures. However, spiders are fascinating and often attractive animals and, like rats, have a
purpose in the medical field.3 This article describes spiders in general, nomenclature, web
designs, properties of their silk and current and future uses.
Spiders (Araneae) are found in all terrestrial ecosystems and even in some aquatic
ones. They are the primary predators of insects, possess a venom system to assist in
capturing prey and produce and utilize silk in many more ways than any other animal.4
Araneae is the most diverse order of arthropods, with 40,700 extant species in 3,733 genera
and 109 families.5 About 13,000 of the known species fashion webs to capture insects and
other small prey.6
Spiders are animals without backbones (invertebrates). They have two parts to their
bodies, a cephalothorax (the head and thorax are fused together) and an abdomen. Eight
legs and usually eight simple eyes are on the cephalothorax. Spiders have fang-like chelic-
erae, which they use to pierce an insect’s hard exoskeleton. Spiders then expel juices that
liquefy their prey’s insides and allow them to be swallowed.
Spider Webs
The evolution of myriad spider silks is reflected in the dazzling abundance of web types.
All designs derive from a simple silk mesh used by ancestral spiders to line earth burrows
more than 380 million years ago.7
Garden spiders (genus Argiope) can spin an orb web (a web with a spiral pattern) that
is almost invisible to humans but visible to insects. The golden orb spider (Nephila clavipes)
can choose the color of silk made to spin its web. Ogre-faced spiders (genus Deinopis) hang
upside down from silk threads attached to branches.
There are also social spiders (Anelosimus eximius) that work together to make
extremely large webs that are attached to branches of trees and shrubs. By working
together, social spiders can catch and eat insects many times larger than they are.
The tiny tropic spider (Wendilgarda) can stretch a strand of web across a stream. Then
it attaches “fishing lines” that attach to the water surface to catch water striders.8 Spiders
do not become attached to their webs. Their legs feature a disengaging mechanism that
enables the arachnid to detach itself instantly from a sticky strand.9
Spider Silk
Spiders are legendary as the materials science experts of the animal kingdom. They can
produce as many as seven different kinds of silk. Silk from spiders is a protein fiber that
has been the subject of intense research because of its impressive mechanical properties,
including high strength and unprecedented toughness.10
All known species of spiders produce some sort of silk throughout their lives.11 The
different silks have unique physical properties such as strength, toughness and elasticity.
The toughness of silk fibers is at least equal to any of the best synthetic high performance
fibers available today.12
To begin a web, a spider anchors a strand of dragline silk three times stronger than
Kevlar used in bullet proof vests and waits for a breeze to blow it to a second attach-
ment point. The web fibers are drawn from dissolved fibroin (fibrous) proteins stored
Arachnophobia (fear of spiders) is quite common, and with good reason. In most of
Europe during the Middle Ages, spiders were considered a source of contamination that
absorbed poisons in their environment.
Any food in contact with spiders was deemed unclean, and if a spider fell into water,
that water was held to be poisoned. Spiders were believed to be messengers of the Black
Plague and death.1 Fear of spiders has a long history. Around the time of the birth of
Christ, parts of Abyssinia (now Ethiopia) were abandoned by the whole population as a
result of a plague of spiders.2
Spiders rank with snakes, cockroaches and rats on the list of most disliked crea-
tures. However, spiders are fascinating and often attractive animals and, like rats, have a
purpose in the medical field.3 This article describes spiders in general, nomenclature, web
designs, properties of their silk and current and future uses.
Spiders (Araneae) are found in all terrestrial ecosystems and even in some aquatic
ones. They are the primary predators of insects, possess a venom system to assist in
capturing prey and produce and utilize silk in many more ways than any other animal.4
Araneae is the most diverse order of arthropods, with 40,700 extant species in 3,733 genera
and 109 families.5 About 13,000 of the known species fashion webs to capture insects and
other small prey.6
Spiders are animals without backbones (invertebrates). They have two parts to their
bodies, a cephalothorax (the head and thorax are fused together) and an abdomen. Eight
legs and usually eight simple eyes are on the cephalothorax. Spiders have fang-like chelic-
erae, which they use to pierce an insect’s hard exoskeleton. Spiders then expel juices that
liquefy their prey’s insides and allow them to be swallowed.
Spider Webs
The evolution of myriad spider silks is reflected in the dazzling abundance of web types.
All designs derive from a simple silk mesh used by ancestral spiders to line earth burrows
more than 380 million years ago.7
Garden spiders (genus Argiope) can spin an orb web (a web with a spiral pattern) that
is almost invisible to humans but visible to insects. The golden orb spider (Nephila clavipes)
can choose the color of silk made to spin its web. Ogre-faced spiders (genus Deinopis) hang
upside down from silk threads attached to branches.
There are also social spiders (Anelosimus eximius) that work together to make
extremely large webs that are attached to branches of trees and shrubs. By working
together, social spiders can catch and eat insects many times larger than they are.
The tiny tropic spider (Wendilgarda) can stretch a strand of web across a stream. Then
it attaches “fishing lines” that attach to the water surface to catch water striders.8 Spiders
do not become attached to their webs. Their legs feature a disengaging mechanism that
enables the arachnid to detach itself instantly from a sticky strand.9
Spider Silk
Spiders are legendary as the materials science experts of the animal kingdom. They can
produce as many as seven different kinds of silk. Silk from spiders is a protein fiber that
has been the subject of intense research because of its impressive mechanical properties,
including high strength and unprecedented toughness.10
All known species of spiders produce some sort of silk throughout their lives.11 The
different silks have unique physical properties such as strength, toughness and elasticity.
The toughness of silk fibers is at least equal to any of the best synthetic high performance
fibers available today.12
To begin a web, a spider anchors a strand of dragline silk three times stronger than
Kevlar used in bullet proof vests and waits for a breeze to blow it to a second attach-
ment point. The web fibers are drawn from dissolved fibroin (fibrous) proteins stored