Tarantulas

Genus Aphonopelma

Common Questions About Tarantulas

Are tarantulas poisonous?
What should I do if a tarantula bites me?
How can I keep tarantulas out of my home and yard?
Health and Medical Disclaimer

Tarantula on stucco wall. See one in action in this video.
Photo by Jay Sharp.

Fearsome looking, the tarantulas – diverse and the largest of the spiders – hold a place in the folklore of cultures across the world. Surprisingly, they also become novel and treasured pets in the homes of some people. More surprisingly, they serve as delicacies at the dining tables of indigenous peoples of the Amazon.

Appearance and Anatomy of Tarantulas Found in the US

• Body and legs are hairy
  
• Tan to reddish brown to black in color
  
• Body size is up to three inches long and two to three inches tall
  
• Leg span of three to five inches
  
• Male tarantulas are longer and slimmer than females
  
• Male tarantulas have much smaller abdomens than females
  
• Exoskeleton (outer shell) includes a fused head and thorax connected at a narrow waist to an oval-shaped abdomen
  
• Eight marginally functional eyes in two groups on the forehead
  
• Mouth and two backward-pointing fangs below the eyes
  
• Two pedipalps (leg-like appendages) for food handling near the mouth
  
• Abdomen contains several vital organs
  
• Abdomen has silk-producing spinnerets at the tip
  
• Four pairs of legs connect to the fused head and thorax

Worldwide Distribution of Tarantulas

"There are about 850 species [of tarantulas] worldwide," according to Barron's Tarantulas and Other Arachnids, and "Their range includes Africa and Madagascar, parts of the Middle East, southern Europe, southern Asia, the Indo-Pacific region, Australia, northern New Zealand, some of the Micronesian Islands… all of Central and South America, parts of the Caribbean, and the United States north to central California and east to the Mississippi River." More than four dozen species populate the U. S. range.

Habitat and Prey

Typically, in the southwestern United States, tarantulas live in solitude in desert basins, mountain foothills and forested slopes. They occupy various kinds of nests, with many species taking up residence in burrows or crevices, which may be sequestered in the ground, along cliff faces, among rocks, under tree bark, or between tree roots.

Some line their burrows with silk. Some surround the entrance with a silken "welcoming mat," which vibrates like guitar strings and sends signals to the spider cloistered there, if potential prey should touch the strands. "A tarantula will attack literally anything that it can subdue: beetles, grasshoppers, locusts, other spiders, small lizards and mice," says biologist Fred Punzo. Tarantulas kill by injecting venom through their fangs into their prey.

Life Cycle

During mating season, which varies from spring through fall, depending on the species and conditions, the males leave their burrows, sometimes en masse, to seek willing females. A male, encountering the silk surrounding the entrance to a female's burrow, calls and dances amorously. He may be rejected or embraced. In either event, he may get eaten up, becoming "a readily available source of protein to fuel development of the next generation," said Pete Taylor, writing for National Wildlife magazine.

Several weeks after mating, the female, said Taylor, produces an egg sac, and six or seven weeks later, "hundreds of tiny spiderlings hatch to begin the cycle anew." After a few weeks, the young disperse to take up their lives. As tarantulas mature, they molt several times, each time shedding their old exoskeleton for a new one. The males may live for several years, the females, for several decades.

A Few Tarantula Facts

The name "tarantula" apparently originated in the 14th century, in the Italian city of Taranto, where people felt compelled to dance the wildly erotic Tarantella if bitten by a spider.

One Venezuelan species has a leg span of some 11 inches; another South American species, a body diameter of some 2 ½ inches; an Arizona species, a body length of 1/3 inch.

Most American tarantulas have barbed and mildly venomous "urticating" hairs on their abdomens, and they use their legs to cast the hairs into the faces of threatening animals, inflicting irritation of soft tissues and eyes.

Some species have on their feet tiny spinnerets that produce sticky silk patches, helping the spider gain a foothold for climbing on slick surfaces such as window glass.
Some species produce a buzzing sound, like cloth ripping, by rubbing appendages together. A tarantula's fangs move up and down; all other spiders' fangs move horizontally.

by Jay Sharp

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

Watch video of a Tarantula and a Tarantula Hawk.