abdomen - for spiders, the hind body part, containing the intestines, lungs, silk gland and sex organs; carries spinnerets at its end

amino acid - any of a large number of organic compounds that contain carbon, oxygen, hydrogen, and nitrogen and that form proteins; certain essential amino acids cannot be produced by the body and must be obtained from food

antenna (antennae) - a pair of appendages on the head of an insect used as sensory organs

apex - the peak or highest point of something; the highest point in a web

Arachne - Greek mythological figure who challenged the goddess Athena to weaving contest. Athena transformed the dying Arachne into a spider

arachnids - subclass archnida, includes spiders and their kin (ie: mites, ticks, scorpions)

Araneidae - family of orb web spiders with many common species (ie: garden spider)

araneomorph spiders - true spiders, vast majority of spiders, around 34,000 species; position of fangs: labidognath; life span: one to a few years

arthropod - animals that have jointed legs and an exoskeleton (skeleton on the outside of their bodies); includes insects, spiders, ticks, centipedes, millipedes, crayfish, lobsters, mites, and scorpions

ballooning - aerial dispersal by small spiders and spiderlings of many species, releasing silk strands from spinnerets, using uplifting air currents for transportation over great distances

Black Widow Spider - poisonous cob web spider, usually non-aggressive. Only the larger and/or adult females are dangerous to humans. Black widow spiders are common all over the U.S. and southern Canada.

Bolas spider - family Araneidae; web reduced to one thread equipped with a drop of glue at its end, which the spider hurls toward its prey

book lung - one (rarely two) pair of lungs on the ventral side of abdomen, numerous thin leaflets for gas exchange, "inside gills"

Brown Recluse Spider - poisonous spider, wounds heal very slowly, occours southern and western U.S.

calamistrum - comb of curved spines on hindlegs of spiders that possesses a specialized spinning field, the cribellum; the ogre-faced spider has a cribellum

camouflage - a protective coloring that makes a spider appear to be part of the natural surroundings

carapace - the tough shield that covers the upper surface of the cephalothorax; it acts as a protection for the delicate internal organs such as an anchor for the muscles of the sucking stomach

carnivorous - meat eating animals, all arachnids except mites, are exclusively carnivorous

cephalothorax - "cephal" meaning "head" and "thorax" meaning "upper body"; the head and upper body are combined into one; also called prosoma

chelicerae - one pair in front of mouth, also called jaws; pincer-like mouth parts of spiders, consist of moveable base segment and moveable fang with poison gland opening near its tip

claws - two or three claws, armed with teeth, at the tip of each walking leg

claw tuffs - bunches of setae at tips of legs, occur in about 50% of all spiders; setae have special adhesive properties enabling spiders to walk on smooth vertical surfaces, and upside down across horizontal surfaces

cob web - irregular meshwork of silk threads, built by spiders

cocoon - silken container produced by female to protect the eggs; also called egg sac; many egg sacs are ball-shaped round, some have a seam and consist of two disks; a few have cocoons specialized forms.

comb-footed spiders - family Theridiidae with many species (ie: American house spider and black widow spiders); name derived from specialized setae forming a comb at terminal segment of fourth leg

compound eyes - an insect's special eyes that are made of hundreds of tiny lenses

conducive - tending to cause, promote, or help bring about a specific result

courtship - performed in some form by all spiders in order to ensure that male and female recognize each other and mate; females show species-typical response. Web-building spiders: courtship consists of pulling the threads of the female's web, trembling abdomen. Hunting spiders: pedipalps and front legs drumming on ground. Jumping spiders and wolf spiders: visual signals such as waving of front legs and pedipalps. In general, courtship proceeds to touching female's legs and finally mounting female to insert part of genital bulb for sperm transfer into female epigynum.

crab spiders - first pair of legs are long and powerful; crab spiders are ambush hunters who often wait on flowers for prey; some species take yellow, pink, green, or whitish coloration of flower.

cribellum - a flattened sievelike plate in front of the spinnerets, through it the calamistrum, a row a curved setae on the next to last segment of the fourth leg, pulls silk; used as a characteristic for identification purposes

cursorial spiders - build no webs for prey capture, but hunt for prey on vegetation or the ground (ie: wolf spiders, jumping spiders, nursery-web spiders, fishing spiders); some hunt by wandering around, but many are ambush hunters that lay in wait for their prey (ie: crab spiders)

Daddy-longlegs - relatives of the spider with body in one piece; conspicuous ones often have very long, thin legs; more that 200 species live in North America; also called harvestmen

Daddy-longleg Spider - common term for spiders of the family Pholcidae, very common in basements; also called cellar spider

digestion - spiders spit digestive enzymes on/in prey to liquefy tissue. They then suck this liquid in together with the prey's body fluids

diversity - having a great variety of types of plant and animal life

diving - performed by fishing spiders that climb down logs or rocks and hide under water to avoid predation; fishing spiders can stay under water for up to 35 - 40 minutes.

diving bell - built by the European Argyroneta (water spider) while under water, silk threads are loosely woven together with water plants to trap air bubbles that are brought down by the spider, used as retreat for eating, mating, and egg laying

dragline - silk line released while walking and climbing, fastened to substrate at regular intervals as a safety line or to retrace a path

egg sac - silken container produced by female to protect the eggs; many egg sacs are ball-shaped round, some have a seam and consist of two disks; a few have specialized forms; also called cocoon

enemies - animals that are harmful or destructive to a spider are toads, snakes, birds, and shrews; spiders of the family Mimetidae hunt only other spiders; some parasites for the spider are several wasp families that hunt spiders and use them as food for their young; pompilid wasps and mud daubers deposit eggs on spiders; flies parasitize spider's egg sacs.

environment - the combination of conditions and surroundings that affect and influence the lives of plants and animals

epigynum - female genitaliea located ventrally in the middle of the abdomen, consist of spermatheca for sperm storage and ducts.

exoskeleton - a hard protective covering, serving the purpose of a skeleton on the outside of an animal's body; such as insects, spiders, ticks, centipedes, millipedes, crayfish, lobsters, mites, scorpions, etc.

eyes - usually eight; in some spiders reduced to six, four, two or none (spiders that live in leaf litter); usually in two to three rows in the head region

fangs - end segments of chelicerae, which connect to the spider's poison glands

female spider - often larger than male; adult female possesses an epigynum

fibroin - a thread that is formed when the silk protein molecules polymerize

fishing spider - large spiders (20 mm), worldwide in distribution; several species live in the U.S.; spiders hunt on the surface of the water and catch the insects that have fallen onto the water surface; also feed on small fish and tadpoles

garden spider - orb-web weaving spider of the family Araneidae

genital bulb - male genital organs to store sperm and transfer sperm to female, located at end segment of pedipalp in adult males

hearing - long, thin setae (trichobothria) are located on legs; each of these setae are connected to a nerve ending; when the setae is bent by air currents the results are nerve impulses which function as sound receivers

herbivore - an animal that feeds mainly on plants

hibernation - depends on climate, spider species living in Canada may hibernate twice as juveniles before becoming adults; the same species may only hibernate once in Virginia and never in Florida, thus resulting in a shorter live span.

hub - center of the orb-web; there are various types of hubs: 1)open (silk removed), 2)containing only radii, 3)containing spiral threads; some orb weavers may rest in hub while other orb web species hide in a retreat and hold onto a signal thread connected to the hub

hypothesis - a tentative explanation for a question that can be tested by experimentation

instinctive behavior - an inborn pattern of behavior that is characteristic of a given species

invertebrates - animals without a backbone; the majority of animals living on earth are invertebrates; their diversity is far greater than those of vertebrates; 30% of all living animals are beetles

jumping spiders - these spiders capture prey by jumping on them; they have excellent vision, the best eyesight of all spiders, they recognize colors and can see clear images

labidognath - positioning of a spider's fangs, in which the fangs are pointing inward and moving sideways

labium - lower lip in spiders; small rectangular sclerite attached to sternum; flip the spider upside down to see it

learned behavior - to gain knowledge of or skill through study or experience

legs - spiders have eight jointed walking legs consisting of seven segments (coxa, trochanter, femur, patella, tibia, metatarsus, and tarsus); lost legs are sometimes regenerated in subsequent molts

male spider - often smaller than female, carries sexual organ after final molt; when adult, often stops hunting and searches exclusively for females; males are sometimes eaten by females after mating, although it does occur regularly in some spider species; if male is attacked by female before mating, she probably mistook him for prey

mammary gland - one of the glands in female mammals that is capable of producing milk

mating - mounting of the male onto female after courtship; male inserts syringe needle-like structure of his genital bulb into opening in the female's epigynum and transfers the sperm

mimicry - the act by which a spider copies the shape of something else (ie: another animal or an inanimate object, such as a dead leaf)

mites - parasites on and in animals (ie: ticks) and plants; mites have modified mouth parts that can bite, suck, or chew, depending on species; many mites carry diseases and are harmful to man and damage livestock and crops

molt - all arthropods shed their hard exoskeleton periodically in order to grow; most spiders become adult after eight to twelve molts; during molting spiders are very vulnerable to predation; spiders perform leg gymnastics (bending and stretching of legs) after molting to keep joints moveable; once adult, spiders will not molt again (exception: tarantulas)

mouth - located behind chelicerae; very narrow opening, only liquefied tissue and body fluids of prey can be sucked in

mud daubers - predatory wasp; hunts spiders and paralyzes them; then places eggs on the living spider and encloses spider in mud nests built by the wasp; hatching wasp larvae then feed on the still living spider

mygalomorph spiders - often called tarantulas or bird spiders; position of fangs: orthognath; live up to 30 years; about 100 species in North America

nocturnal - resting during the day and active at night

nursery web spider - family Pisauridae; female builds a nursery web for hatching spiderlings

ogre-faced spider - family Deinopidae; occurs in Florida and other subtropical and tropical countries; builds specialized web that is held stretched between the front legs and thrown over the prey like a casting net

omnivore - an organism that eats both plant and animal food

orb web - resembles a wagon wheel; web consists of frame threads, radii (spokes of the wheel) and a spiral of sticky threads to capture prey; center of the wheel is called a hub and is surrounded by a free zone that contains no sticky spiral, allowing the spider to cross from one side of the web to the other; several spider families build orb webs

orthognath - the positioning of the spider's fangs are pointing downward

parental care- protection of eggs and care of spiderlings is provided by the female; spiders care for eggs: production of egg sac, carried attached to spinnerets (wolf spiders) or in chelicerae (nursery web spiders); some spiders guard the egg sac; certain spiders provide care for spiderlings (nursery web); spiderlings are carried on back of abdomen (wolf spiders); spiderlings are fed by mouth (comb-footed spiders); spiderlings devour mother (Eresidae)

pedicel - a spider's waistline

pedipalps - first pair of appendages at prosoma, shorter than walking legs, used for prey, holdling, cleaning, etc; site of sexual organ in adult male spiders (genital bulb)

plumose setae - hair-like setae located around the abdomen of the fishing spider, used to trap their prey

poison - usually within the prosoma; in tarantulas restricted to base segment of chelicerae; opening of poison gland at tip of fangs; all spiders possess posion glands except for the family Uloboridae

polymer - any of a large number of natural or synthetic chemical compounds of extremely high molecular weight, formed of simple molecules linked together into giant molecules

polymerize - to make or combine into a polymer; change into larger molecules with a certain arrangement

position of fangs - pointing down: orthognath position, occurs in all tarantulas and relatives; pointing inward and moving sideways: labidognath position, occurs in most spiders

predation - the act or process of being hunted and eaten by another animal

predator - an animal that hunts and eats other animals; spider predators are toads, frogs, lizards, snakes, birds, wasps, and parasites

prey - an animal that is hunted and is eaten by another animal; spiders almost exclusively eat live insects; some spiders may occasionally catch fish and tadpoles (water spiders); large tarantulas may catch birds or mice occasionally; most spiders are not specialized on any particular prey group among insects and catch any live insect of appropriate size; many spiders have problems with the formic acid of ants and do not eat them for this reason

prosoma - front body part, consists of head and thorax region joined together; carries chelicerae, pedipalps, and legs; also called cephalothroax

radii - (the plural form of the word radius) radial threads attached to the outer from threads and converge in the hub, thus forming the spokes of the orb web; the number of radii is often characteristic of specific species

regenerate - to replace (a damaged or lost part of an organ) by growing new tissue

resting - often done in a retreat; spiders either nocturnal (resting during the day, active at night) or diurnal (resting during the night, active at day); often when we see a spider in what we assume is the resting position, spiders are actually hunting (ie: remaining motionless at center of hub; in retreat but hanging on to signal thread; motionless on the surface of the water)

retreat - built in all thinkable places, but often location is species-typical; retreats on trees, under logs and rocks, in crevices, within the vegetation under leaves and debris attached to each other by silk threads; in web spiders, the retreat and the web are connected by a signal thread on to which the spider holds; some spiders have a specialized retreat (ie: the diving bell built by the European water spider); numerous types of silk lined tubes and burrows in the soil are constructed to serve as a retreat

sclerite - hard plates on the back of the abdomen

scopulae - thick brushes of specialized setae on the underside of tips of legs, the tarsi and metatarsi; enables a spider to cling to smooth surfaces, even walking over a vertical glass surface or across the ceiling

setae - often numerous, covering spider body and legs at varying densities; may be colored, iridescent (ie: jumping spider); serve numerous functions in various spider groups; spiders have different types of tactile setae to sense vibrations and sound; taste setae are on tips of legs; urticating setae in tarantulas are used for defense; serrated bristles in comb-footed spiders draw out sticky silk; plumose setae in fishing spiders trap around abdomen

signal thread - silk line connecting spider in retreat and center of the hub; enables the spider to monitor vibrations of the web while remaining in the retreat

silk - produced by silk glands, released through spinnerets, consists of protein; liquid within the spigots of spinnerets turns into solid strands by the mechanical force of pulling; different types of silk are used for or during various activities (ie: dragline, egg sac, web, retreat, mating, etc.)

silk glands - up to six different types of silk glands are located in the hind end of the abdomen; silk is released through spinnerets

smell- spiders can smell with tiny holes in front feet

species - a single kind of plant or animal; about 34,000 species of spiders known so far worldwide in a little over 100 families; presumably many more species are undiscovered

spiderlings - very young spiders, when they hatch from the egg

spigot - openings of the silk ducts of the silk glands located in the abdomen of the spider; spiders have different spigots for different types of silk glands

spinnerets - located at the end of the abdomen, usually six present, highly moveable; spinnerets carry spigots, which are the openings of the silk ducts of the silk glands; spiders have different spigots for different types of silk glands; in some spiders there is an additional spinning plate (cribellum)

spitting spider - family Scytodidae; have a large, vaulted prosoma containing modified poison glands that produces a sticky substance which glues prey to the ground or substrate

stabilimentum - silken zigzag bands added to the radii close to the hub; function unknown; occurs in orb webs of certain Araneidae

sternum - hard piece of integument covering the ventral side of the prosoma

sticky spiral - dense spiral of silk threads carrying glue droplets, laid down from the web's periphery towards the hub at the same time that the temporary spiral is removed by spider; sticky spiral often contains many turning points, making it a time-consuming part of the web to build

stomach - located in prosoma, acts as a sucking pump; special muscle arrangement around stomach allow digestive enzymes to be pressed out and liquefied tissue to be sucked in

substrate - the material upon which another material is built upon

survive - to stay alive or in existence

synthetic - relating to or involving synthetics; not of natural origin

tarantula - (name used in the Americas; also called bird spider; in Africa termed baboon spider) very hairy, often large, living for up to 30 years; name "tarantula" originally used for large Italian wolf spider (araneomorph spider) occurring around the city of Taranto; bite of that spider was supposed to cause sickness that could only be healed by continuous dancing

taste - many taste setae are located at tips of legs

temporary spiral - wide spiral built during orb web construction form center of web towards periphery; removed when the sticky spiral is built from periphery towards center of web

tick - an arthropod and spider relative that sucks blood from other animals

trapdoor spiders - several groups of spiders construct burrows closed by various types of trapdoors; design and function of trapdoors are species typical

triangle spider - family Uloboridae; builds only one triangle shaped sector of a full round orb-web (ie: web is shaped like a slice of pizza)

trichobothria- long, thin hair-like setae that are located on a spider's legs; each of these setae are connected to a nerve ending; bending of trichobothria through air currents results in nerve impulses

Uloboridae - family of small orb web spiders which have no poison glands; triangle spider forms a living bridge between two parts of her web, then lets web collapse over the prey

urticating setae - ultra-fine hairs that cover the tarantulas abdomen; it should be noted that "hair kickers" (tarantulas that scratch their abdomens vigorously with a rear leg, usually in defense) will send clouds of these ultra-fine hairs into the surrounding atmosphere, these hairs have caused allergic reactions on occasion, including irritations that can become inflamed

venom - produced in poison glands; except for Uloboridae, all spiders possess venom glands; venom of most spiders is a nerve toxin, which acts on the synaptic vesicles

ventral - belly side, underside of an animal

vertebrates - all the animals that have a backbone such as fish, amphibians, reptiles, birds, mammals; there are far more species of invertebrates on earth than vertebrates

vibrations - best developed sense in spiders, distinguish frequencies of various vibration sources ( ie: struggling prey; courtship; rain; predators)

vision - well developed only in jumping spiders that see sharp images and color; most other spiders see movements but do not have color vision

water spider - European genus Argyroneta, lives in fresh water ponds with unpolluted water, swims and dives freely, builds diving bell, catches aquatic insects

webs - often species typical; each spider species can only build its particular type of web; there are very many web forms (ie: purse webs, orb webs, sheet webs, cob-web, trap doors, etc.); many spiders build reductions (or parts) of webs (ie: Bolas spider, triangle spider, etc.)

wolf spiders - family Lycosidae (cursorial spiders); numerous species, some large; female attaches egg sac to spinnerets and carries spiderlings on back of abdomen

wrapping - many web spiders wrap their caught prey in silk, which is digested and ingested together with liquefied tissue and body fluids of prey