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Tarantula

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Tarantulas are a diverse group of large, often hairy spiders within the family Theraphosidae.

Austin tarantula
Austin tarantula

Scientists have identified more than one thousand different species across almost 200 genera. While many people use the name "tarantula" for members of this specific family, the term is often applied to other spiders in the infraorder Mygalomorphae. These include "false tarantulas" like funnel-web or purseweb spiders. Because of their impressive size and unique appearance, many species have become popular in the exotic pet trade. However, owners must be careful with New World species. These spiders possess urticating hairs, which are specialized bristles that can cause skin irritation. In extreme cases, these hairs can even cause damage to the eyes.

Lasiodora parahybana, claws
Lasiodora parahybana, claws

Like all arthropods, tarantulas are invertebrates that rely on an exoskeleton for muscular support. Their body is divided into two main sections: the prosoma, also called the cephalothorax, and the opisthosoma, or abdomen. These two parts are joined by a narrow, waist-like connection called the pedicel. This pedicel is actually part of the prosoma, but it allows the abdomen a wide range of motion. To move their legs, tarantulas use internal pressure. They increase the pressure of haemolymph, which is their bodily fluid, entering the leg to make it extend. When walking, they move in a specific pattern. The first and third legs on one side move at the same time as the second and fourth legs on the other side.

Lasiodora parahybana, chelicerae 05
Lasiodora parahybana, chelicerae 05

A tarantula's anatomy includes several specialized appendages attached to the prosoma. They have eight legs, each consisting of seven segments: coxa, trochanter, femur, patella, tibia, tarsus, pretarsus, and a claw. At the end of each leg, they have two or three retractable claws for climbing. They also have a group of bristles called a scopula, which helps them grip smooth surfaces like glass. Near the mouth, they have two pedipalps used for feeling and gripping prey. The most important tools for hunting are the chelicerae. These are two double-segmented appendages that house venom glands. The fangs are hollow extensions of the chelicerae that inject venom. Unlike true spiders, whose fangs face each other like pincers, tarantula fangs face downwards.

Tarantula in burrow
Tarantula in burrow

Tarantulas occupy many different ecological niches around the world. Most species are terrestrial burrowers that live in the ground. They use silk to line their burrows, which helps stabilize the walls and makes climbing easier. Other species are arboreal, meaning they live in trees. These tree-dwelling spiders often reside in silken "tube tents." Their diets consist mainly of large insects and other arthropods like centipedes or millipedes. Because they are powerful ambush predators, the largest species can even consume small vertebrates. This includes lizards, mice, bats, birds, and small snakes.

Mojave Tarantula
Mojave Tarantula

The size and variety of tarantulas are truly remarkable. The Goliath birdeater, found in Venezuela and Brazil, is considered the heaviest species. It can weigh over 6 ounces and reach a leg span of up to 12 inches. Its fangs can grow as long as 1.12 inches. While the Goliath birdeater is the heaviest, the pinkfoot goliath (Theraphosa apophysis) is thought to have the greatest leg span. Other giants include the Brazilian salmon birdeater. Colors vary wildly across the globe. Some species are cobalt blue, while others have metallic blue legs with orange abdomens. They live in environments ranging from deserts and savannas to rainforests and cloud forests.

Poecilotheria Regalis
Poecilotheria Regalis

The history of the name "tarantula" is actually a bit of a misunderstanding. Originally, the name referred to Lycosa tarantula, a wolf spider from the Mediterranean. This name came from the Italian town of Taranto. Over time, English speakers began applying the name to any large, ground-dwelling spider. This led to the name being used for the Theraphosidae family, even though they are not closely related to wolf spiders. Scientists also use the term "pelma" in many genus names, such as Aphonopelma. This term relates to the "footsole" or the scopula of the spider. In modern times, some researchers use "pelma" simply to mean a member of the theraphosid family.

Tarantula, Attacking Position, Photo by Sascha Grabow
Tarantula, Attacking Position, Photo by Sascha Grabow

Understanding tarantulas requires distinguishing them from other similar creatures. They can be confused with huntsman spiders, but huntsman spiders belong to a different group called Araneomorphae. One way to tell them apart is by their breathing organs. Tarantulas have two book lungs, whereas most true spiders have only one. They also have different types of spinnerets. While most spiders have six, tarantulas have only two or four. These flexible, tube-like structures are used to exude silk. By studying these specific anatomical and behavioral traits, scientists can accurately classify these fascinating predators within the complex tree of life.

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🖼️ Images & Media (16)
File:Tarantula Burrow.jpg
Tarantula Burrow.jpg
File:Tarantula in burrow.png
Tarantula in burrow.png
File:Austin tarantula.jpg
Austin tarantula.jpg
File:Mojave Tarantula.jpg
Mojave Tarantula.jpg
File:Poecilotheria Regalis.jpg
Poecilotheria Regalis.jpg
File:Lasiodora parahybana, claws.JPG
Lasiodora parahybana, claws.JPG
File:Tarantula, Attacking Position, Photo by Sascha Grabow.jpg
Tarantula, Attacking Position, Photo by...
File:Tarantula, food leftovers.JPG
Tarantula, food leftovers.JPG
File:Lasiodora parahybana, eyes.JPG
Lasiodora parahybana, eyes.JPG
File:Cyclosternum fasciatum, eye region.jpg
Cyclosternum fasciatum, eye region.jpg
File:wiki tarantula.jpg
wiki tarantula.jpg
File:Fried Tarantula in Cambodian Restaurant.jpg
Fried Tarantula in Cambodian Restaurant.jpg

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