Tarantulas: Natural History and Interesting Facts

They’re creepy, they’re crawly, they’re fuzzy, they’re tarantulas. Tarantulas are one of the world’s most recognizable spiders due to their distinctive size, fearsome appearance, and hairy spines along the body. The name “tarantula” refers to a diverse group of spiders in the Theraphosidae family. Tarantulas are native to every continent in the world (except Antarctica) but are mostly concentrated in the southern hemisphere, often in temperate and arid environments. To date, there are more than 1,236 known species of tarantula across 147 genera.

Source: J. Fowler via Flickr CC-BY 2.0

Tarantula Description

Since tarantulas encompass several groupings of spiders, their physical appearance can differ depending on the species. Like all spiders, tarantulas have a 2 segment body consisting of a head and fused thorax/abdomen complex. Tarantulas have 8 legs, the front two of which have adapted for grasping and manipulating objects in the environment. Each leg also has a claw-like appendage meant to grasp the surface it’s standing on.

The Mexican Pink Tarantula (Brachypelma klaasi). Source: G. Chemilevsky via WikiCommons Public Domain

All known species of tarantula are venomous to some degree and a bite from some species can cause serious discomfort and damage. Along with the venom, tarantulas have large fangs that can leave painful puncture wounds.

Tarantulas are also known for their hairy appearance. These hairs act as a defense mechanism as they can break off and irritate the eyes of predators. The bristles on the abdomen are the sharpest and some species of tarantula can actually fling hairs at their opponents when they feel threatened. Some species lack bristles entirely. These kinds of species usually have more potent venom. All species of tarantula can produce silk and most species incorporate silk into their hunting and mating practices.

Tarantula Behavior

Despite their large size and fearsome appearance, most tarantulas are docile and non-aggressive. Depending on the species, tarantulas can hunt in the trees or they can chase their prey along the ground. Tarantulas usually eat smaller insects such as centipedes, millipedes, flies, crickets, grasshoppers, and even other spiders. Tarantulas themselves are prey for several animals, including wasps (specifically tarantula hawks), lizards, frogs, and birds, and mammals. Tarantulas will bristle their hairs and ready their fangs when they feel threatened.

Source: M. Foubister via WikiCommons CC-BY-SA 2.0

Like most spiders, tarantulas periodically shed their exoskeletons through molting. Tarantulas can live for years and some species take 10 years to reach maturity. Once males reach maturity, they weave a bed of silk and deposits his sperm into it, mixing it with his forelegs. When the male finds a female, he inserts his pedipalps into an opening near the abdomen to fertilize the egg. The female can lay anywhere between 50-200 eggs per brood and females usually lay eggs about once a year. Unlike many spider species, female tarantulas stick around to guard their eggs and keep their hatchlings safe.

Tarantula Interesting Facts

  • Tarantulas can regrow lost limbs
  • Tarantulas can measure anywhere between a ½ inch and almost foot-long leg span
  • Some female tarantulas can live up to 40 years and survive on nothing but water for 2 years
  • The name “tarantula” originally referred to wolf spiders, a completely distinct family of spiders. The usage of the word shifted when tarantula species were discovered in the Americas.
  • Some species of tarantula such as the Mexican red-kneed tarantula (Brachypelma hamorii and Brachypelma smithi) are endangered due to the exotic pet trade