Arachnid Trivia

7/29/2019 Arachnid Trivia

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Arachnids

Arachnid, term for animals in the class including the scorpions,

spiders, daddy longlegs, mites, and ticks, and certain other eight-

legged land invertebrates. Fossils suggest that arachnids were

among the first animals to live on land, perhaps in the early

Devonian Period, nearly 400 million years ago. About 60,000 species

are known, although many, especially mites, remain undiscovered or

undescribed. Arachnids are found throughout the world in nearly

every habitat, but they reach their greatest size and diversity in

warm arid and tropical regions.

Characteristics

The arachnid body is divided into two parts: anterior and posterior.

The anterior part, called the cephalothorax, contains sense organs,

mouthparts, and limbs in pairs. The first pair of limbs-the chelicerae-

may form pincers or poison fangs, and the second pair-the

pedipalps-may serve as pincers, feelers, or legs. The other limb pairs,

generally four, are used for walking. The posterior part of the body,

the abdomen, bears the genital opening and other structures. It is

usually equipped with modified gills called book lungs. Most

arachnids are solitary except at the time of mating, when a variety of

complex behavior patterns may be observed. Females may guard

eggs or young, which are often born live.

Behavior and Importance

Arachnids are usually predaceous. Often they hunt or lie in wait for

small animals such as insects. Food may be partly or wholly broken

down by secreted fluids and then sucked in. Arachnids have simple

eyes and various prey-subduing structures, such as the segmented,

stinging tail of scorpions and the abdominal spinnerets with which

spiders construct elaborate insect traps (orbs or webs). Mites

constitute the largest and most diverse order of arachnids, followed

by the spiders. Some mites feed on plants and a few species are

serious agricultural pests. Some are predaceous, often feeding on

other species of mites. Parasitic lifestyles are common among mites

and many are of veterinary and medical importance. Ticks are a

distinct bloodsucking subgroup of mites specialized for parasitizing

reptiles, birds, and mammals. Ticks carry organisms that causeserious human diseases, such as Lyme Disease. The bites of some

spiders and the stings of a few species of scorpions are dangerously

poisonous to humans (see Black Widow Spider, Brown Recluse

Spider). However, most arachnids are harmless and contribute to

the balance of nature by controlling the populations of the insects

they prey on or the plants, reptiles, birds, or mammals that serve as

their hosts.

Scientific classification

Arachnids constitute the class Arachnida, in the phylum Arthropoda.

The class is divided into 11 orders: the Acari or Acarina (mites and

ticks), Amblypygi (tailless whipscorpions), Araneae (spiders),

Opiliones (daddy longlegs), Palpigradi (palpigrades),

Pseudoscorpiones (false scorpions), Ricinulei (ricinuleids),Schizomida (micro whipscorpions), Scorpionida (true scorpions),

Solpugida (windscorpions), and Uropygi (whipscorpions).Arachnids

Arachnids are a group of arthropods that includes eight-legged

creatures such as spiders, ticks, mites, daddy-long-legs,

pseudoscorpions, scorpions, and whip scorpions. There are about

75,500 species of arachnids alive today. The articles listed below

provide information about the characteristics, classification and

evolution of arachnids.

Arachnids are a diverse group of arthropods that include spiders,

scorpions, harvestmen, ticks and mites. This profile explores basic

facts about arachnids including their classification, diet, habitat and

what makes them different from other arthropods.

Harvestmen

Harvestmen are a group of arachnids that include more than 6,300

species. This profile explores basic facts about harvestmen including

their classification, diet, habitat and what makes them different

from other arachnids.

The Amazing Jumping Spider

Can you imagine what it's like to have eight eyes, eight legs, and the

ability to jump fifty times your height in distance? If so, then you

might have an idea of what it's like to be a jumping spider.

The Tangled Web of Spider Classification

Spider classification is a complicated business. Since 1900,

taxonomists have reshuffled the spider order nearly 20 t imes.

Unlike insects, spiders cannot fly--but they can balloon! Young

spiderlings pull out silk until the breeze can lift them into the sky.

Most don't travel high or far, but some have been seen at altitudes

of 10,000 feet and on ships more than 200 miles from land. Most

ballooners are very small spiderlings, but adult spiders have been

captured by planes with nets.

Female wolf spiders carry their egg sacs behind them, attached to

their spinnerets. After the spiders emerge, they crawl onto the

mother's abdomen and hold on while she actively runs and hunts.

After about a week, the spiderlings molt to a larger size and then

take off to live on their own.

While most spiders live for one year, a few may have more than one

generation each year. Some spiders can live 3 to 4 years, and certain

tarantulas are known to live for 25 years or longer.

Male spiders are almost always smaller than the females and are

often much more colorful. Some males are so small that they

actually look like they're newly hatched.

Male spiders are unique among all animals in having a secondary

copulatory organ. While most animals spread their sperm in water

or insert them into the female, mature male spiders weave a small

"sperm" web. They place a drop of semen on the web, suck it up

with their pedipalps (special structures on their first "arm"), and

then use the pedipalp to insert the sperm into a female.

Some spiders live underwater all of their lives. They surface to

collect a bubble of air, which acts as an underwater lung. An

underwater spider fills its bell-shape web with air bubbles and

derives oxygen from them.

The fisher or raft spider is able to walk across the surface of a pondor other body of water by skating like a water strider. When it

detects prey (insects or tiny fish) under the surface, it can quickly

dive to capture its dinner.

Spiders are not only predators, they are often prey. Many birds and

animals love to feed on them. The coatimundi, a relative of the

raccoon, are fond of eating large tarantulas.

Hummingbirds use the silk from spider webs to weave together the

sticks that form their nests.

A few species of trapdoor spiders use their abdomens to "plug" their

burrows to protect themselves from wasps. The abdomen is flat on

the back end and tough enough that a wasp's stinger can't penetrateit.

Spiders eat more insects than birds and bats (combined) eat, so they

should be considered another of human's best friends. They play a

big role in controlling insect populations.

The decoration in the web of some orb-weaving spiders serves a

variety of purposes: It can be a warning so birds don't fly into the

web, an attractant so insect-prey fly in on purpose, or an "um-

brella" to shade the spider from the hot sun.

Some orb weavers make very unusual webs. One variety greatly

increases the area above the center, creating what is sometimes

called a ladder web that extends eight feet above the spider.

Bolas spiders make webs of a single line with a sticky "ball," or bola,

on the end. These spiders can twirl the bolas in the air. Moths are

attracted to the smell and fly toward the web until they hit it and

stick. The spider then reels in its catch.

Spider Sense: Fast Facts on Extreme Arachnids


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With more than 37,000 described species, spidersfrom the tiny

armored spider to the Goliath birdeater tarantulacruise the Earth

on eight legs. Get a glimpse of the spiders' world with the juicy bites

below:

The ancient Greek poet Ovid spun the tale of a young woman

named Arachne, who boasted that she could weave as well as the

goddess Athena. After a weaving contest between mortal and

goddess, Athena began beating Arachne, who tried to hang herself

in fright. Athena turned the arrogant weaver into a spider, and

Arachne and her descendants have since then been weavers thathang from threadsor so the story goes.

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"Arachnid" isn't just a highfalutin word for spider. Spiders are

arachnids, but not all arachnids are spiders. Arachnids are members

of a class of animals that includes spiders, scorpions, mites, and

ticks. What they all have in commonand what distinguishes them

from insectsare four pairs of legs and no antennae.

The spider world has its own Goliaththe Goliath birdeater

tarantula (Theraphosa leblondi). Found in the coastal rain forests of

northeastern South America, this spider can be as big as a dinner

plate and has been known to snatch birds from their nests. The

spider world's David? The smallest spider is a mygalomorph spider

from Borneo. Its body is the size of a pinhead.

A spider might give Superman, the Man of Steel, a run for his

money. Some silk made by orb weaver spiders rivals the tensile

strength of steel. It's been suggested that the silk would be more

effective than Kevlar in bulletproof vests. One problem: corralling a

group of territorial spiders to produce the tough stuff. In addition,

each spider produces so little silk that it wouldn't be practical to

become a spider farmer.

Almost all spiders carry venom, but its purpose is to stun or kill

their insect prey, not to attack humans. Of the known spider species,

only about 25 are thought to have venom that has an effect on

humans. The two bestknown venomous spiders in the U.S. the

black widow and the brown reclusehave not been proven to havecaused any deaths in more than two decades.

The brown recluse spider, Loxosceles reclusa, often gets a

particularly bad rap. While its natural range is in the south-central

United States, people all over the country blame bites on this

species.

Australia's most notorious spider, the Sydney funnel -web spider,

has not been known to cause any deaths since 1980. In this species,

the male spider's venom is more toxic than the female'sa rarity

among spiders.

Spiders produce seven kinds of silk, ranging from the sticky stuff to

trap and wrap their prey to superstrong threads for support. Spiders

also use their silk as parachutes and to shelter themselves and their

young. The various types of silk are produced by different

specialized silk glands and nozzles called spinnerets. No one spider is

able to produce the full range of silk.

Spiders have evolved numerous ways to catch their prey, which is

mostly insects but can also be frogs, fish, lizards, snakes, and birds.

Some spiders are masters of disguise, blending into their

background so that they look like parts of a flower or a leaf. Others

hide under "trapdoors," jumping out of their hiding places to snatch

a passing meal. Still others can leap many times their body length,

covering great distances to grab their prey.

Bolas spiders "fish" for moths by dangling a sticky strand of silk

impregnated with a substance that is similar to the pheromone that

moths use to attract mates. Some spiders can walk on the surface of

water. Others live underwater.

Spiders eat spiders. Females sometimes eat their mates, even while

they are mating. Some spiders specialize in hunting down other

species of spider and have evolved ways to grab them, even whentheir victims are in the center of their strongholdstheir webs.

Spiders are hunted as much as they are hunters. Birds, lizards,

snakes, scorpions, and other spiders all prey on spiders. Some

insects also hunt down spiders, including the mantis and a wasp that

specializes in catching and paralyzing spiders. The wasp buries the

spider alive, so that its young can feed on fresh food when they

hatch.

Most spiders have eight eyes. Some have no eyes and others have

as many as 12 eyes. Most can detect only between light and dark,

while others have well-developed vision. Experiments have

demonstrated that some spiders can recognize and respond to

specific shapes on television monitors. However they're equipped tosee, all spiders have highly evolved systems to detect prey and

danger.

Some cultures have found ways to use a spider's trap to get their

own meals. In the South Pacific native people have made fishing

nets from a spider's silk. People encourage nephila spiders to build

webs between two bamboo stakes, which are then used for angling.

A spider eats about 2,000 insects a year, so spiders are good to

have around the home. The reward for the trouble? All too often, a

smack with a newspaper. Spiders are usually killed by people

because the arachnids seem scary, not because they're dangerous.

If you are bitten by a spider, the California Poison Control Centerrecommends keeping the wound clean and treating the symptoms

that follow. If the bite becomes infected or does not heal, see a

physician.

Some cultures chomp down on spiders as a delicacy and have been

doing so for hundreds of years. In the South Pacific people have

eaten the same spiders they use to weave fishing netswith some

diners saying the cooked spiders taste nutty and sticky like peanut

butter. In spots in Southeast Asia, street vendors sell fried spiders to

passersby.

According to urban legend, the daddy longlegsthose gangly

creatures that seem to hang from corners around the house are

poisonous, but have mouths too small to bite humans. The name"daddy longlegs" is used in several countries to refer to a few

different speciesincluding harvestmen, which aren't actually

spiders and have no venomand spiders in the family Pholcidae,

which are not known to have venom that affects humans.

Pesticides won't successfully knock out spiders. The highly mobile

eight-legged animals will come back to an area that's been sprayed

because, unlike insects, they're not strongly affected by residual

pesticides. To prevent spiders from coming inside the house,

arachnologists suggest sealing off any cracks or gaps where spiders

can slip in. But to control insects that can cause damage to your

propertysuch as termiteswhy not let their natural predators,

spiders, inside to do the work?

Facts about Scorpions

The Scorpion doesnt have good vision in spite of the fact that it has

so many eyes. They have at least 6 but they can have as many as 12.

The Scorpion has a very good sense of smell. They use it to find food

and to hide from danger.

They rely on vibrations from their surroundings to help them

determine what is taking place in their environment.


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It is true that a Scorpion is able to tell the difference between light

and dark.

Young Scorpions ride on their mothers back for the first weeks of

life.

The average lifespan in the wild for the Scorpion is 2 to 10 years.

Some have lived as long as 25 years in captivity.

There is fluorescent in the Scorpion that is believed to be part of the

molting process.

All Scorpions are venomous. Only about of them have a type of

venom that is potent enough to make someone very ill or to kill

them.

Antarctica is the only place on Earth where you wont find the

Scorpion living.

The Scorpion loves to live around rocks, sand, and trees. However,

they are very adaptable and have been found living in some very

unusual places.

The oldest artifacts of Scorpions date back 430 million years.

Some species of Scorpions can live for up to a year without any food

or water.

Not all of them live in the hottest regions. There are some species

which successfully live in the colder areas where it can freeze.

They are nocturnal and will usually stay in holes or under rocks

during the day.

They are extremely sensitive to light so they arent going to be out

roaming around in the sun.

Scorpions can only consume a liquid diet. The venom they inject into

prey allows the insides to be turned into liquid that they suck out.

Sometimes the females will consume the males after mating if he

doesnt move quickly.

The young are called Scorplings. They will stay with their mother

until they complete their first molt.

The nearly born young Scorpions also contain venom. The mothers

may sometimes consume their young.

The females are typically larger than the males of the same species.

The most dangerous Scorpion species is the Arizona Bark Spider

which is also called the Bark Scorpion.

Scorpions tend to live in areas that are from 67 degrees Fahrenheit

to 98 degrees Fahrenheit.

They are closely related to ticks, mites, and spiders.

They get most of their water from prey but they have been seen

drinking plain water from time to time.

Scorpions need soil around their living environment so that they can

thrive.

The range in size from inch to 7 inches.

There are approximately 90 species of Scorpions that live in the

United States. Texas has 18 of them and they also have one of the

largest populations of these living creatures anywhere in the USA.

Some of the very dangerous Scorpions live in North Africa and the

Middle East.

Each species of Scorpion has its own type of venom which is why

the toxicity levels vary.

They dont have bones. Instead they have an exoskeleton that is

made out of the same substance as human fingernails.

There is only an anti-venom for treatment with certain types of

Scorpions.

Migraine headaches that last for a week or longer can be the result

of the after effects of a dangerous Scorpion sting.

There are about 2,000 species of scorpions; about 40-50 of them

have poison strong enough to kill people.

Scorpions are 3 to 8 inches long.

Scorpions are for the most part nocturnal.

Scorpions and Shoes

Scorpions like snug and tight spaces. Thats why when a scorpion

happens to enter a house, one popular place to find comfort is in

shoes!

Physical Features

Some scorpions have up to 10 eyes, though they cant see very well.

The scorpion tail has a stinger with venom glands.

Scorpions have florescent materials on their shell. With ultraviolet

light, they can glow in the dark.

Female Scorpion Aggression

After mating, a female scorpion might become aggressive and kill

and eat the male scorpion.

A mother scorpion might even eat her offspring if she became

hungry.

Scorpions are members of the class Arachnida and are closelyrelated to spiders, mites, and ticks. They are commonly thought of

as desert dwellers, but they also live in Brazilian forests, British

Columbia, North Carolina, and even the Himalayas. These hardy,

adaptable arthropods have been around for hundreds of millions of

years, and they are nothing if not survivors.

There are almost 2,000 scorpion species, but only 30 or 40 have

strong enough poison to kill a person. The many types of venom are

effectively tailored to their users' lifestyles, however, and are highly

selected for effectiveness against that species' chosen prey.

Scorpions typically eat insects, but their diet can be extremely

variableanother key to their survival in so many harsh locales.

When food is scarce, the scorpion has an amazing ability to slow itsmetabolism to as little as one-third the typical rate for arthropods.

This technique enables some species to use little oxygen and live on

as little as a single insect per year. Yet even with lowered

metabolism, the scorpion has the ability to spring quickly to the hunt

when the opportunity presents itselfa gift that many hibernating

species lack.

Such survival skills allow scorpions to live in some of the planet's

toughest environments. Researchers have even frozen scorpions

overnight, only to put them in the sun the next day and watch them

thaw out and walk away. But there is one thing scorpions have a

difficult time living withoutsoil. They are burrowing animals, so in

areas of permafrost or heavy grasses, where loose soil is not

available, scorpions may not be able to survive.

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Arachnid Trivia