Land invertebrates
CITE
We have made every effort to follow citation style rules, but there may be some minor differences. If in doubt, please refer to the appropriate citation style manual.
Tarantulas. (2022). In Q-files Encyclopedia, Life, Land invertebrates. Retrieved from
https://www.q-files.com/life/land-invertebrates/tarantulas
"Tarantulas." Life, Land invertebrates, Q-files Encyclopedia, 10 Feb. 2022.
https://www.q-files.com/life/land-invertebrates/tarantulas.
Accessed 19 Mar. 2024.
Tarantulas 2022. Life, Land invertebrates. Retrieved 19 March 2024, from
https://www.q-files.com/life/land-invertebrates/tarantulas
Life, Land invertebrates, s.v. "Tarantulas," accessed March 19, 2024.
https://www.q-files.com/life/land-invertebrates/tarantulas
Tarantulas
Tarantulas are mostly large, hairy spiders, although some species are as small as fingernails. They feed mostly on insects, but larger species can kill lizards or rodents. Some types hunt prey mainly in trees while others are ground-dwellers, capturing their prey by ambushing them. They also have barbed hairs on their abdomens, called urticating hairs, which they flick at their attackers to cause itching.
Legs
A tarantula has four pairs of legs, each leg having seven segments and claws at the tip. Its fifth pair of "limbs", called pedipalps, help the tarantula to feel its way around, to grip prey, and are used by the male to deliver sperm to the female during mating.
Fangs
Yet another pair of appendages, the chelicerae, are positioned just below the eyes and carry the spider's fangs. They are hollow and contain venom glands. They are used to inject venom into prey or attackers. The fangs can be folded back into the chelicerae, in the same way as a penknife blade folds back into its handle. The tarantula's mouth is a narrow, straw-like opening that can only suck. So anything the spider consumes must be liquidized first of all. Large prey, such as rodents, must first be crushed, ground up and and coated with digestive juices.
Senses
The tarantula has eight eyes, with some bigger than others and arranged in two rows of four. A tarantula's eyes can tell the difference between light and dark and see movement and shape. The tarantula also uses touch to sense its surroundings. The hairs or spines on its its body, called setae, are very sensitive and can pick up the vibrations given off by the movements of its prey. These then direct it towards its prey. The setae can also detect chemical signals, called pheromones, given off by other tarantulas of the same species.
Bird-eating spider
The biggest tarantulas, the bird-eating spiders, can have leg spans of up to 30 centimetres (12 inches)—as wide as a dinner plate. Despite their name, they usually eat beetles, grasshoppers and small reptiles. Many species of bird-eating spider are found in the rainforests of South America. These spiders chase their victims down and bite them with their fangs.
Defence
Tarantulas have their own predators, including giant centipedes. When threatened, the spiders rear up with their front legs in the air, make a loud hiss and flick hairs at their attacker. Species of tarantula with urticating hairs can kick these hairs off: they are flicked into the air at a target using their back pairs of legs. If all else fails, they may strike with their huge fangs. Although they look fearsome, most species of bird-eating spider are harmless to humans. In fact, some people even keep them as pets.
Tarantula hawk wasps
The most specialized of a tarantula's predators are large members of the wasp family, called tarantula hawk wasps. The largest of them will attack and kill large tarantulas. Having paralysed them with their sting, the wasps lay their eggs inside their hosts' stomachs. When the larvae hatch, they feed on the still-living spider's body, eventually killing it in the process.
Consultant: Chris Jarvis