Tarantulas
Genus Aphonopelma

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.
See one in action in this video.

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.

Comparisons

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).

Description

Tarantulas are members of the spider family Theraphosidae (order Araneida). They have a 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 enemy's 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.

Vocalization

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

Cephalothorax

Round

Eyes

8 close together

Behavior

Tarantulas are sluggish and 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, while 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.

Habitat

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 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 its 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 later consumption.

Breeding

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. Males may also die a natural death or be eaten by the female even prior to mating.

Once mated, female tarantulas store sperm in special leaf-shaped organs known as spermathecae. Immediately before fertilization and egg laying begins, she begins to construct 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.

Conservation

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.

Cautions

If a bite should occur, the venom when injected into humans usually causes only slight swelling, with some numbness and itching which disappears in a short time. The bite has been compared in intensity with a bee or wasp sting. Caution should be used when handling or near a tarantula, as with any wild creature. Even when trained as a pet, the tarantula should be handled carefully.

While most bites are unlikely to cause problems other than pain at the site, all puncture wounds have the potential of becoming infected, and should be carefully treated. Some people are allergic to tarantula venom, and may have an anaphalytic shock reaction, which could cause severe illness. Skin exposure to the urticating hairs will often cause itching and a rash. Hands should be washed after the handling of a tarantula, or gloves worn during exposure.

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. Any sign of allergy or breathing problems should be cause for concern - seek medical attention.

More pictures of Tarantulas by Kenton Elliott at Calico. They were photographed on Main Street at Calico Ghost town in California.