Tarantulas
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Tarantulas are spiders belonging to the family Theraphosidae. They are characterized by having tarsi (feet) with two claws and claw tufts.
The word tarantula applies to two very different kinds of spider. The spider that originally got this name is neither particularly large, particularly hairy, nor particularly venomous. Its scientific name is Lycosa tarantula, which makes it one of the wolf spiders. Its name comes from that of Taranto, a town in Southern Italy. The bite of this spider was once believed to cause a fatal condition called tarantism. The cure for the disease was believed to involve wild dancing of a kind that has come to be called the tarantella. Actually, the bite of this kind of spider is not even particularly painful, let alone life-threatening. There appears to have been an entirely different kind of spider in the fields around Taranto that caused fairly severe bites (one candidate is the malmignatte or Mediterranean black widow, Latrodectus sp.), but the tarantulas, being wolf spiders, were fairly large, out in the open, and were frequently seen running around, which drew attention to them, and so they got the blame. Join that factor with the belief in tarantism and the supposed need for wild dancing to prevent sure death, and the fearsome world-wide reputation of the tarantula was guaranteed.
When people who knew about the tarantulas emigrated to the Americas and discovered fearsomely large and hairy spiders in the New World, they bestowed the name "tarantula" on them. Those spiders belong to the Suborder Mygalomorphae, the Family Theraphosidae and the Family Dipluridae. They can be quite large.
Tarantulas can be kept as a house pet. A terrarium with an inch or two of damp vermiculite or a mixture of soil and sphagnum moss (Do not use cedar shavings as they are toxic to many spiders) on bottom provides an ideal habitat (burrowing tarantulas will require a deeper layer). Tarantulas can be fed a variety of living animals (insects, small mice, small fish in the water bowl, and reptiles are on their menu).
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The true tarantula
The true tarantulas are all spiders of the family Theraphosidae, sometimes called bird spiders or monkey spiders. Related species include funnel-web spiders and trap door spiders, which are sometimes also grouped among the tarantulas. The family Theraphosidae includes over 300 different species of tarantulas, divided over 12 subfamilies (formerly 13). Tarantulas are excellent climbers.
Tarantulas are long-legged, long-living spiders, whose entire body is covered with short hairs. Tarantulas inhabit tropical to temperate regions in South America and Central America, Mexico, and the southwestern United States, Asia, Southern Europe, Africa and the Middle East.
The body of the tarantula pictured above is approximately 2.5 inches (6.2 cm) long. Despite their scary appearance and reputation, none of these fearsome-looking creatures make the list of deadly spiders (spiders having a strong toxin, dangerous to humans), and this particular kind of tarantula is regarded as being especially docile. Some people claim that there are deadly varieties of tarantulas somewhere in South America. This claim is often made without identifying a particular spider although the "banana tarantula" is sometimes named. The dangerous Brazilian wandering spider (Phoneutria nigriventer) is probably the spider in question as it sometimes found hiding in clusters of bananas and is one of several spiders called the "banana spider". It is not a tarantula but it is fairly large (about an inch long), somewhat hairy, and is regarded as aggressive.
Size, color and type
Depending on the species, their body length may vary from 1-3 inches (2.5 - 7.5 cm), with 3 to 5 inch (8-12 cm) leg spans (their size when including their legs). Some species are even larger and have 10-inch leg spans. On the average, they weigh from 2 to 3 ounces (60-90 grams). The largest species is the Goliath birdeater (Theraphosa blondi), however some breeders and hobbyists believe otherwise. The Pinkfoot goliath tarantula (Theraphosa apophysis) was described 187 years after the goliath birdeater; therefore it is not as well-known, although legspans of up to 13 inches have been recorded.
The majority of tarantulas are brown or black, however some species have more extensive colour scheme, ranging from cobalt blue (cobalt blue tarantula, Haplopelma lividum), black with white stripes (pink zebra beauty or Eupalaestrus campestratus and Brazilian giant white knee tarantula or Acanthoscurria geniculata) to metallic blue legs with vibrant orange abdomen (greenbottle blue tarantula, Chromatopelma cyaneopubescens). Their natural habitats include savanna, grasslands such as the pampas, rainforests, deserts, scrubland, mountains and cloud forests. They can be divided into terrestrial, arboreal or burrowing or a combination of two of these types.
Hair
Besides the normal hairs covering the body of tarantulas, some also have a dense covering of stinging hairs, called urticating hairs, on the abdomen, opisthosoma, as a protection from enemies. These hairs are only present on some New World specimens (only the subfamilies of Ischnocolinae, Aviculariinae and Theraphoseae) and are absent on specimens of the Old World.
These fine hairs are barbed and contain a mild venom. Some species can 'kick off' these hairs: the hairs are launched into the air at a target. Tarantulas also use these hairs for other means. They mark their territories with these hairs. Some arboreal species coat their webs with these hairs. Some species do the same thing with their egg cocoons.
To predators and other kinds of enemies, these hairs can be lethal or simply a deterrent. With humans they can cause irritation to eyes, nose and skin. The symptoms range from species to species, from person to person, from a burning itch to a minor rash. Some tarantula enthusiasts have had to give up their spiders because of allergic reactions to these hairs (skin rashes, problems with breathing and swelling of the affected area).
Nests
Tarantulas live in a variety of nests. Burrowing tarantulas live under the ground, in burrows. These burrows are either dug by the spider itself or abandoned burrows (from, for instance, rodents) or ready-made crevices. The tunnels are lined with silk and form a webbed rim at the entrance that conceals it. Others make their homes under rocks or tree trunks or under the bark of trees. Others build silken nests on trees, cliff faces, the walls of buildings or in plants such as bananas and pineapples.
Growth, life, and mating
To grow, tarantulas, like other spiders, have to shed their exoskeleton periodically. This process is called moulting. Young tarantulas may do this several times a year, while full grown specimens will only moult once every year or so, or sooner in order to replace lost limbs or lost urticating hairs.
Tarantulas may live for many years. Most species take 2 to 5 years to mature to adults, but some species take up to 10 years to reach maturity. Upon reaching adulthood, males have only a short time remaining in their lives, about one year to a year and a half - they will immediately go in search of a female to mate with. Once the male is a mature adult, it will most likely never moult again before dying.
The habit of male spiders wandering in search of mates makes them especially visible. In late summer and early autumn (September and October in the northern hemisphere), the males will leave their hiding places and walk about, hoping to encounter the hiding place of a female with which to mate. They are willing to cross roads and trails in this quest, and that is when they are most likely to be observed.
When the mature male encounters the burrow of a female, he will draw the female out and signal his intentions to mate by vibrating his body and tapping his front legs. If the female is receptive to mating, she will vibrate and tap her legs also. After mating, the male must get away quick, or it is possible he will be eaten. A female tarantula who is unreceptive to mating may also eat the male as he attempts to mate. This however is less common among tarantulas than other spiders, certain species of tarantulas have been known to mate multiple times over the course of several weeks.
Females will continue to moult after reaching maturity and because of this are able to regenerate lost limbs and have a longer life. Female specimens have been known to reach 30 years of age or even 40 years, and have survived on water alone for 2 and an half years. On the average, females live 20-30 years and males 10-12 years, depending on species, if well cared for.
Reproduction
Needs some more information on mating
The females deposit 50 to 2000 eggs, depending on the species, in a silken egg sac and guard it for 6 to 7 weeks. The young spiders remain in the nest for some time after hatching and then disperse by crawling in all directions.
Tarantulas usually live in solitude and will attack others of their own kind. There are however exceptions, such as the pinktoe tarantula (Avicularia avicularia), which can be kept communally. Keep in mind ALL tarantulas are cannibalistic; it is possible one tarantula will eat the other. Avicularia Spp. are simply more tolerant of each other. If the vivarium is big enough, has enough hiding spots, and the specimens are about the same size and well fed, there should be little or no cannibalism. Keeping tarantulas communally is not recommended and should not be attempted except by experienced keepers.
Nocturnal predator
Tarantulas are nocturnal predators, killing their prey by injecting venom through their fangs. It typically waits partially hidden at the entrance to its retreat to ambush passing prey. It has sensitive hairs that enable it to detect the size and location of potential victims from the vibrations caused by their movements. Like many other spiders, it can not see more than light, darkness, and movement (see spiders for more about their eyesight), and uses its sense of touch to perceive the world around it.
Bites and Treatment
There are no substantiated reports of tarantula bites proving fatal to a human. However, the effects of a tarantula bite are not well known. While the bites of many species are reported to be no worse than a wasp sting, other accounts say these bites are some of the most painful. Because other proteins may get included when a toxin is injected, some individuals may suffer severe symptoms due to allergy rather than poison.
Tarantulas will not bite unless provoked or disturbed. The defensiveness varies by species. Just the bites of tarantulas can be quite painful since the fangs are large and can pierce all the way through the skin of the victim.
New world tarantulas (those found in North and South America) are equipped with urticating hairs on their abdomen, and will almost always use these as a first line of defense. Old world tarantulas (from Asia) have no urticating hairs, and are more likely to attack when disturbed. Old world tarantulas often have more potent, medically significant venom.
Before biting, tarantulas may signal their intention to attack by rearing up into a "threat posture", which may involve raising their abdomen into the air, lifting their front legs into the air, spreading and retracting their fangs, and making a loud hissing noise by rubbing their fangs together. Their next step, short of biting, may be to slap down on the intruder with their raised front legs.
First Aid: Clean the bite site with soap and water and protect against infection. Skin exposures to the urticating hairs are managed by applying and then pulling off duct tape or other sticky tape, which carries the hairs off with it. If any breathing difficulty or chest pain occurs, go to a hospital as this may indicate an anaphylactic reaction.