View Full Version : Week 26 - Tarantula

November 29th, 2007, 01:57 PM

Vital Stats

Weight: 1-3 oz.
Length: 1-5"
Span: 3-10"

Sexual Maturity: 3-9 yrs.
Mating Season: Fall
Incubation: 6-9 weeks
No. of Young: 500-1000

Birth Interval: 1 year
Lifespan: 25-40 years
Typical diet: insects,
Geography – Range

Tarantulas occur worldwide . Those found in North America occur in the southern and southwestern states, including the dry and warmer parts of the southern California. These are smaller and generally have a body length of less than 2 inches and a leg span of from 3 to 4 inches..

Related Species

The Desert Tarantula (Aphonopelma chalcodes) grows 2 to 3 inches long and is colored gray to dark brown. It is common to the Sonoran, Chihuahuan and Mojave deserts of Arizona, New Mexico and Southern California.

The most common North American tarantula is Eurypelma californicum, found in California, Texas, and Arizona. A 30-year life span has been recorded for one individual of this species. Certain South American tarantulas, which have a body length of up to almost 3 in., build large webs and eat small birds.


The majority of tarantulas are black or brown but some species exhibit striking colors. The Mexican Red-legged Tarantula (Brachypelma smithi) has bright-red leg markings and, Cobalt Blue Tarantula (Haplopelma lividum) has legs colored deep blue.

The tarantula family includes the largest spiders known. The Goliath Tarantula (Theraposa leblondi) which inhabits South America, reaches a body length of 5 inches with a leg span of up to 12 inches . Even the small tarantulas reach a relatively large body length of 1.5 inches (4 centimeters).


Tarantulas are members of the spider family Theraphosidae (order Araneida). They have hairy body and legs and come in wide color variation, from a soft tan, through reddish brown to dark brown or black.

A conspicuous bald spot seen on the abdomen of many tarantulas results from the spider's defensive behavior against its vertebrate enemies. When confronted, the spider will rub its hind legs over its body, brushing off irritating hairs into an enemies eyes. These hairs are replaced during each successive molt.

The cephalothorax and abdomen Tarantulas, the front and rear parts of the body, are round. Their 8 eyes are closely grouped, with a pair in the middle and 3 on each side of the face. They have large fangs 2 pairs of slits on the underside of the abdomen that lead to the respiratory organs called book lungs. Book lungs have many folds lying close together like the pages of a book through which blood passes to acquire oxygen from the outside air.


Many also produce a hissing sound by rubbing their jaws, front legs, or palps against each other.




8 close together


Tarantulas are sluggish spend most of their time hidden in burrows or other retreats, becoming active in the late afternoon from spring through fall Some dig their own burrows, others use ready-made crevices or abandoned rodent holes. Some make their homes under rocks or logs or under the bark of trees. They are not gregarious, meaning there is only one spider per burrow.

While North American tarantulas are exclusively ground-dwellers living in burrows others build silken retreats on trees, cliff faces, the walls of buildings or in crop plants such as bananas and pineapples.


The tarantula prefers to live in dry, well-drained soil. If the soil is suitable, the female digs a deep burrow which she lines with silk webbing. This helps prevent sand and dirt from trickling in. Otherwise, she hides in cracks in logs and under any loose-lying debris.

Food & Hunting

The tarantula is a nocturnal hunter. It does not spin a web to capture its prey, but catches food it by speed It will take virtually anything of the right size that moves within range, but feeds primarily on small insects like grasshoppers, beetles, sow bugs, other small spiders and sometimes small lizards.

The tarantula strikes with its fangs, injecting venom and grasping the prey with its palps, arm like appendages between the mouth and legs. Then the Tarantula grinds its victim into a ball, secretes digestive juices onto it, and sucks up the liquefied prey. It may also wrap the ball in silk for a later meal.


Tarantulas do not reach sexual maturity for several years. During this time they undergo a series of molts, and until they reach maturity you can't tell the male from the female. The mature male is quite dark, nearly black, while the mature female is brown. The degree of coloring varies with the species and geographical location. Upon maturity the males abandon their burrows and go forth to seek a mate.

In the Fall, males locates a receptive female by the scent she leaves on the silk of her burrow, and after performing a courtship dance, mates. Males usually die a few months after mating, but females may live and produce eggs for 25 years or more. It may die a natural death or be eaten by the female, sometimes even before mating can occur

Once mated, female tarantulas store sperm in special organs known as seminal receptacles. Immediately before fertilization and egg laying begins, she partially constructs a cocoon within her burrow.

With the silken foundation laid, the female then releases a mixture of eggs and sperm through her genital opening into the cocoon . Once the eggs are deposited, she finishes sealing up the cocoon with silk then stands guard until the 500 to 1,000 young hatch. Young tarantulas emerge from their cocoon 6 to 9 weeks after fertilization, then venture off on their own in another 2 to 3 weeks.


Tarantulas have many natural enemies including lizards, snakes, spider-eating birds and the Tarantula Hawk. The large metallic blue, green and red wasp is the Tarantula’s fiercest and most dreaded enemy. Once it has found and paralyzed the spider with its poisonous sting, the wasp drags its victim to a prepared burrow, deposits its eggs in the spider's abdomen and seals its victim in. Upon hatching, the wasp larvae feed on the tarantula's body.

Although the tarantula is frightening in appearance, the chances of being bitten by it are rare and, because it has a rightful place in the outdoors, it should not be wantonly killed or persecuted. If its presence is not desired, it can be easily placed in a container and transported to some area where it can continue, unmolested, to live its useful life.


Even if through carelessness a bite should occur, the venom when injected into man causes only slight swelling, with some numbness and itching which disappears in a short time. The chances of being bitten are so slight that one has little need to worry.

Tarantulas are harmless to humans and are often trained as pets, although they can inflict painful bites if provoked.

Although both males and females are capable of inflicting a bite when threatened, they rarely do so and their venom is considered to be non-toxic to humans.

Bites are unlikely to cause problems other than pain at the site. Skin exposure to the urticating hairs will cause itching and a rash.

First Aid: Clean the bite site with soap and water and protect against infection. Skin exposures to the urticating hairs are managed by removing the hairs with tape.

Curious Facts

Tarantulas are harmless to humans and can be trained as pets.

The Tarantula spins no web but catches its prey by pursuit.

There are more than 800 species of Tarantulas.

November 29th, 2007, 02:11 PM
Awww tarantulas are amazing. :)
Just got a pink toe for my best friend, her name is Izzabella. ;)

Thanks for sharing! :)

December 5th, 2007, 01:08 AM
Yikes, those pics gave me goosebumps! I'm pretty much afraid of large spiders.