Scientific name: Class – Arachnida
Family – Theraphosidae
Classification status: Several species are threatened
There are over 1400 species of tarantula, but like all spiders tarantulas have two body segments. There is the cephalothorax and the abdomen. They have eight legs which are covered with tiny hairs which help the tarantula to grip better when climbing on things such as glass. On the end of each leg there are two or three retractable claws which are used by the tarantula for a better grip when climbing. Apart from the legs they have two other pairs of appendanges, one pair which is used to help with feeling, grabbing prey and mating in the mature male. The other pair has the fangs attached to them. Most tarantulas are brown however some species are blue, black with white stripes, have yellow leg markings or blue legs with an orange abdomen.
As there are many species of tarantulas their size varies but they can be from 2 to 10 cms (1 to 4 in) long and have leg spans of 8 to 30 cms (3 to 12 in). The largest species of tarantula can weigh over 85 grams (3 oz) however the goliath birdeater species can weigh up to 150 grams (5.3 oz) and have a leg span up to 30 cms (12 in).
All tarantulas have a hard exoskeleton that they must shed when they are having a growth spurt. When they are ready to molt they lay down on a silken mat and flip over on their back. The old exoskeleton opens on the back and the tarantula expands and contracts its body until it comes off. Once this is done the spider will wait until the new exoskeleton has hardened it will flip back over. During this process they are also able to regrow any legs that they have lost through injuries.
Female tarantulas can live up to about 25 to 30 years however males only live about 5 to 7 years because once males reach maturity generally at 2 to 5 years, they only have one or two years to live.
Tarantulas are carnivores. Insects are there usual diet but they can target bigger prey like frogs, toads, lizards and mice. One of the species the South American bird eating spider can even prey on small birds. They kill their prey with a bite from their fangs. The fangs have venom which is injected into the prey to kill them and then they will secrete digestive enzymes which turn the prey to liquid, the tarantula will then suck them up with its straw-like mouth openings. Tarantulas can also kill their prey by crushing them with its powerful mouth parts.
Tarantulas are found in all continents except Antartica, but they are most commonly found in South America. They are found in rain forest, desert and scrubland.
Once the male has reached maturity and is ready to mate he will weave a mat on a flat surface and deposit sperm onto it which he then might dip his pedipalps into it, until he finds a female to mate with. When he finds a female they will exchange signals to see whether they are the same speices and to help the female become receptive to the male. Once mating has occurred the male will leave quickly as sometimes the female will eat the male spider. The female will make a silk cocoon in her home for the eggs. She will lay 75 to 1000 eggs in the cocoon and then seals it up with silk. She will guard the cocoon for six to nine weeks until the young hatch. After hatching they will stay in the nest for a few weeks before going of on their own.
Even though tarantulas have a reputation for being dangerous they are often the object of other predators. They have some ways of protecting themselves against enemies. Some species have a thick covering of hairs on thier abdomen called urticating hairs. The tarantula if threatened will flick these hairs of their abdomen, the hairs are barbed and irritate the predator even killing small animals like mice.
Tarantulas don’t use webs like most spiders to catch their prey, they hunt them and kill using their venom or powerful jaws. They may however sometimes spin a trip wire which alerts them when something is approaching their burrow.
Some species of tarantulas live primarily in the trees while others live on or near the ground. They all produce silk with the tree dwelling species generally live in a silk tube tent while burrowing species use the silk to stabilise the burrow walls and to help climb up and down the burrow.
Even though people are generally scared of tarantulas they are not really harmful to humans. They will generally not bother you if you don’t bother them and if they do bite you their bite is really no worse than a bee sting. They do not have powerful enough venom to kill a human although the bite may hurt for a while. The most severe symptoms come from an allergic reation to the toxins not actually the venom,
Tarantulas are thin-skinned spiders particulary on their abdomen, so if they were to fall even from a short height they can rupture their exoskeleton and die.
Because tarantulas moult throughout their lives they are able to regenerate limbs that have been lost the next time that they moult. Sometimes they will eat the limbs they have lost to recycle protein.
Sometimes once the male has mated with the female the female will eat the male as she sees him as a good source of protein.