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True tarantulas are spiders belonging to the family (Greek for thera "wild animal, beast" + phos "light"). Certain members may also be known as bird spiders, monkey spiders, baboon spiders or rain spiders. They are characterized by having tarsi (feet) with two claws and claw tufts, called scopulae. Related families include the funnel-web spiders and the trap door spiders, which sometimes are also called tarantulas. The family Theraphosidae includes over 800 different species of tarantulas, divided over 12 subfamilies (formerly 13) and 113 genera. This article primarily discusses the true tarantulas; however the history of the name "tarantula", as well as other spiders referred to by the term, are discussed below.
General Characteristics Tarantulas are long-legged, long-living spiders, whose entire body is covered with short glittery hairs called setae. Tarantulas inhabit tropical to temperate regions in South America and Central America, Mexico, and the southwestern United States, Asia, Southern Europe, Africa and Australia. In South Africa they are sometimes referred to as Baboon Spiders. The body of the tarantula pictured to the left is approximately 2.5 inches (6.2 cm) long. Despite their often scary appearance and reputation, none of the true tarantulas are included in the list of deadly spiders (spiders having a strong toxin, dangerous to humans), and this particular kind of tarantula is regarded as especially docile. Some people claim that there exist deadly varieties of tarantulas somewhere in South America, a theory which provides the basis of the story in the American film Arachnophobia. 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 is 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. However, the Sydney funnel-web spider (Atrax robustus), is perhaps the most aggressive, highly venomous, and likely to bite repeatedly and envenomate enthusiastically. It is a species of the venomous funnel-web tarantulas, a member of the same suborder as the true tarantulas but not one of the Theraphosidae. Size, color and type Tarantulas are not all large. Depending on the species, their body length may vary from 2.5 - 10 cm (1-4 inches), with 8-30 cm (3 to 12 inch) leg spans (their size when including their legs). Size is measured by measuring from the tip of the back leg to the tip of the front leg on the same side. The largest species of tarantulas can weigh over 90 grams (3 ounces). The Goliath birdeater (Theraphosa blondi) from Venezuela and Brazil is generally regarded to be the largest species, 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. However legspans of up to 33 cm (13 inches) have been reported. In general the males of most species are slimmer and longer legged than the females. The majority of tarantulas are brown or black, however some species have more extensive coloration patterns, 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 are generally divided into terrestrial types (that frequently make burrows) and arboreal types. Many tarantula species exhibit pronounced sexual dimorphism. Males tend to be smaller (especially the abdomen) and may be quite colourful, as in the very large Bolivian and Peruvian species Pamphobeteus antinous, in which the female is dark brown and the male shiny iridescent purple. Males also tend to have shorter lifespans. For these reasons, most tarantulas kept as pets are female. Hair Besides the normal hairs covering the body of tarantulas, some also have a dense covering of irritating hairs (about 10,000 per mm² ) and are absent on specimens of the Old World. They help in phylogenetic studies of Theraphosinae . These fine hairs are barbed, and designed to urticate, but do not contain 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, using them to mark territory or to line the web or nest (the latter such practice may discourage flies from feeding on the spiderlings). To predators and other kinds of enemies, these hairs can range from being lethal to simply being a deterrent. With humans, they can cause irritation to eyes, nose, and skin, and more dangerously, the lungs and airways, if inhaled. The symptoms range from species to species, from person to person, from a burning itch to a minor rash. Tarantula hair has been used as the main ingredient in the novelty item "itching powder." 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). Habitat and behavior Tarantulas are nocturnal predators, killing their prey by injecting venom through their fangs. The hungry tarantula 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. Some species also use their silk fiber to detect motion (when prey triggers a line). Like many other spiders, it cannot see much 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. That being said, they are anything but sloppy or imprecise about the way they capture their prey. They generally seem to choose prey on the basis of how dangerous they are perceived to be, the general size of the potential prey animal, etc. Some tarantulas succeed in occasionally capturing small birds, small mammals such as mice, and even small fish, but their ordinary prey consists of insects such as crickets (for ground dwellers) and moths (for arboreal species). Nests Tarantulas live in a variety of nests. Burrowing tarantulas live underground, in burrows. These burrows are either dug by the spider itself, or else they reuse burrows abandoned by rodents or other small creatures, or they find ready-made crevices. The tunnels are lined with silk and a webbed rim is formed at the entrance so as to conceal it. Other tarantulas make their homes under rocks or tree trunks or under the loose bark of trees. Still others build silken nests on trees, cliff faces, the walls of buildings or in plants such as bananas and pineapples. Tarantulas are well suited for climbing. Even heavy-bodied terrestrial tarantulas such as Grammostola rosea can climb vertical sheets of glass, but climbing very high presents a serious danger to them since any substantial fall can rupture their abdomens. The arboreal species are lighter of body and more able to withstand substantial falls. Growth, life, and mating Like other spiders, tarantulas have to shed their exoskeleton periodically in order to grow, a process called molting. Young tarantulas may do this several times a year, while full grown specimens will only molt 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 taking 2 to 5 years to reach adulthood, but some species may take up to 10 years to reach full maturity. Upon reaching adulthood, males typically have but a 1 to 1.5 year period left to live and will immediately go in search of a female with which to mate. It is rare that upon reaching adulthood the male tarantula will molt again. 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 also vibrate and tap her legs. After mating, the male must get away quickly, or it is possible that he will be eaten. A female tarantula who is unreceptive to mating may also eat the male if he attempts to mate. This result, 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. Since females will continue to molt after reaching maturity, they are able to regenerate lost limbs and increase their lifespan. Female specimens have been known to reach 30 years of age and even 40 years, and have survived on water alone for up to 2.5 years. If well cared for, females can expect to live 20-30 years and males 10-12 years, depending on the species. Reproduction
Tarantula taxonomy The family Theraphosidae is divided up into 12 sub-families, as follows. Sub-family Spelopelminae was recently merged with Theraphosinae, and its single genus merged into the genus Hemirrhagus. Subfamily Acanthopelminae Acanthopelminae, first described by Frederick Octavius Pickard-Cambridge in 1897, is a sub-family of small, terrestrial New World tarantulas. This sub-family has only one genus, Acanthopelma, and two species, A. beccarri and A. rufescens, found in Guyana and Central America. Genus: Subfamily Aviculariinae Aviculariinae are a sub-family of tropical, tree-dwelling New World tarantulas. They range from the Caribbean to South America, and are commonly known as "pinktoe" tarantulas. The genera Avicularia, Ephebopus and Pachistopelma possess urticating hairs, but cannot "flick" them into the air; instead the hairs are pressed into an enemy upon contact. Genera: Subfamily Eumenophorinae Eumenophorinae are a sub-family of old-world tarantulas, mostly from Africa and surrounding regions. Genera: In addition, some authors place genus Proshapalopus (a genus found in Brazil, and not in Africa) in this sub-family. Subfamily Harpactirinae Sub-family Harpactirinae are a group of old-world tarantulas from Africa, though smaller than Eumenophorinae. They are known as baboon spiders for their hairy legs and the thick black scorpulae at the end of their feet, which are said to resemble baboons. Genera: Subfamily Ischnocolinae Sub-family Ischnocolinae contains spiders from around the world. Genera: Subfamily Ornithoctoninae The earth tigers of sub-family Ornithoctoninae are a group of old-world tarantulas which are found primarily in Southeast Asia, southern China, and Borneo. This group includes the infamous Chinese bird spider, and species in this sub-family are known for being ill-tempered. Genera: Subfamily Poecilotheriinae Sub-family Poecilotheriinae are tree spiders from India and Sri Lanka, some of which are considered . This sub-family contains only a single genus. Genus: Poecilotheria Simon, 1885 Subfamily Selenocosmiinae Sub family Selenocosmiinae. This sub-family consists mainly of tarantulas from East Asia and Australia. Like the East Asian tarantulas in Ornithoctoninae, these are known for their strong venom and defensive disposition. The genera Psalmopoeus and Tapinauchenius do not have urticating hairs, unusual among New World species. Genera: Subfamily Selenogyrinae Sub-family Selenogyrinae consists of tarantulas from India and Africa. Genera: Subfamily Stromatopelminae Sub-family Stromatopelminae are tree-dwelling tarantulas from western Africa. Genera: Subfamily Theraphosinae Sub-family Theraphosinae consists of new-world terrestrial tarantulas with urticating hairs. The majority of spiders kept as pets are of this sub-family. Subfamily Thrigmopoeinae Sub-family Thrigmopoeinae are Indian tarantulas. Genera: Other tarantula genera A few genera are presently not well-classified, and/or have classifications which are disputed. Tarantulas and people Because of their large size, tarantulas are noticed and utilized by humans in ways which other spiders generally are not. Tarantulas as pets Tarantulas can be kept as pets and are considered good "apartment pets" by many, being quiet animals, requiring surprisingly little maintenance or cleaning, since unlike snakes and lizards they have no detectable odor. Because of their docile personality and beauty, the most common species kept as pets are the Chilean rose tarantula (Grammostola rosea, for their price) and the mexican redknee tarantula (Brachypelma smithi, for their beauty). These two species are also some of the easier to care for and are usually easy to handle and some of the more gentler types often have a habit of relaxing in peoples' hands, especially when calm or even wanting to keep warm. Tarantulas also make quite inexpensive pets. Most species can be purchased as juveniles for $20-$50. Adults can be quite expensive as they approach breeding age and adults of many species can easily reach the several hundred dollar range. Housing for most species can cost another $40 or so. Unfortunately, few pet shops have the required knowledge for proper tarantula care and can often subject tarantulas to poor living conditions due to this ignorance. Various species can require significantly different care and a care sheet for the specific species you are caring for should be used. A terrarium with an inch or two of damp ground coconut fiber, or a mixture of soil and sphagnum moss (but not with cedar shavings as they are toxic to many spiders) on bottom provides an ideal habitat. (Burrowing tarantulas will require a much deeper layer.) Ambient temperature and humidity vary by species, with most thriving between 75 degrees and 80ºF (24 to 27ºC) and between 40% and 80% humidity. Tarantulas can be fed a variety of living animals (insects, small mice or Pinky Mice, small fish in the water bowl, and reptiles are some of the foods tarantulas eat). Tarantulas should NOT be fed vertebrates on a regular basis as the calcium in the bones will cause complications during molting and may kill the tarantula. A tropical roach colony is a good way to maintain a food supply for a number of tarantulas. The discoid cockroach and death's head cockroach in particular are very easy to care for and will not infest your home if they escape. The death's head cockroaches can be kept in an aquarium with no lid since they cannot climb glass and don't fly. Maintaining a colony of death's head cockroaches only requires keeping them in the dark, feeding them a handful of dog food every couple of weeks and misting them with water every day or two. Hybrid death's head cockroaches are just as good and half the price. Other tarantulas that may make interesting pets are the Brazilian (or "giant") whiteknee, Chaco golden knee, and Brazilian salmon pink birdeater. These are three of the larger species, each growing over 8 inches with the Brazilian birdeater sometimes reaching 10 inches and considered by many to be the largest species that is docile enough to handle. The Chaco and the Brazilian whiteknee tarantula are also quite pretty. Chaco golden knee tarantulas are generally quite docile. Giant white knees and the salmon birdeaters tend to be nervous and sometimes aggressive. The foregoing are terrestrial tarantulas, i.e., they generally live in burrows or natural shelters near the ground. Arboreal tarantulas require different housing since, when adult, they make webbed shelters well above ground. A few of the Avicularia spiders are well suited for beginners. Those include Avicularia avicularia and Avicularia metallica, which are generally quite calm and rarely bite. (Any spider will bite if it is being hurt or put in fear for its life.) The arboreal spiders can have large legspans, but their bodies are much less massive than the typical terrestrial tarantulas. Tarantulas as food On one of their TV specials, National Geographic illustrated the methods used by some Amazonian peoples to hunt and cook tarantulas. A tarantula was captured by holding it down with a stick and its legs were then bent upward and bound together. The creature was then roasted alive in a folded leaf. The taste of its meat is said to resemble that of shrimp. The Goliath birdeater tarantula (Theraphosa Blondi) is considered a delicacy by the indigenous Piaroa of Venezuela. Another appearance of the tarantula as food was made on Anthony Bourdain's A Cook's Tour. Fried tarantulas are also considered a delicacy in Cambodia. Bites and treatment There are no substantiated reports of tarantula bites proving fatal to a human, though there have been reports that a Chinese bird spider may have killed a small child in southern China. In general, though, the effects of the bites of all kinds of tarantulas are not well known. While the bites of many species are known to be no worse than a wasp sting, accounts of bites by some species are reported to be very painful. There might indeed be deadly tarantulas of some kind, but no human has yet provoked one of them sufficiently to get a fully envenomated bite. Because other proteins are included when a toxin is injected, some individuals may suffer severe symptoms due to an allergic reaction rather than to the venom. For both those reasons, and because any deep puncture wound can become infected, care should be taken not to provoke any tarantula into biting. Tarantulas are known to have highly individualistic responses. Some members of species generally regarded as aggressive can be rather easy to get along with, and sometimes a spider of a species generally regarded as docile can be provoked. Anecdotal reports indicate that it is especially important not to surprise a tarantula. 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. These hairs will irritate sensitive areas of the body and especially seem to target curious animals who may sniff these hairs into the mucous membranes of the nose. These hairs generally do not irritate the hands or other tough areas of skin. Some species have more effective urticating hairs than others. The goliath birdeater is one species known for its particularly irritating urticating hairs. 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 prosoma and lifting their front legs into the air, spreading and extending their fangs, and (in certain species) making a loud hissing noise called Stridulating. Their next step, short of biting, may be to slap down on the intruder with their raised front legs. If that response fails to deter the attacker they may next turn away and flick urticating hairs toward the pursuing predator. Their next response may be to leave the scene entirely, but, especially if there is no line of retreat, their next response may also be to whirl suddenly and bite. Tarantulas can be very deceptive in regard to their speed because they habitually move very slowly, but are able to deliver an alarmingly-rapid bite when sufficiently motivated. First Aid for bites Encourage bleeding to wash out the puncture wounds from within. Then clean the bite site with soap and water and protect it against infection. As with other puncture wounds, antiseptics may be of limited use since they may not penetrate to the full depth of a septic wound, so wounds should be monitored for heat, redness, or other signs of infection. Skin exposures to the urticating hairs can be treated by applying and then pulling off some sticky tape such as duct 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. As with bee stings, the allergic reaction may be many times more dangerous than the toxic effects of the venom. Origin of the name "tarantula" The word tarantula applies to several very different kinds of spider. The spider originally bearing that name is one of the wolf spiders, Lycosa tarentula, found in the region surrounding the city of Taranto (or Tarentum in Latin), a town in Southern Italy. Compared to true tarantulas, wolf spiders are not particularly large or hairy. The bite of Lycosa tarentula was once believed to cause a fatal condition called tarantism, whose cure was believed to involve wild dancing of a kind that has come to be identified with the tarantella. However, modern research has shown that the bite of Lycosa tarentula is not dangerous to human beings. There appears to have existed a different species of spider in the fields around Taranto responsible for fairly severe bites. The likely candidate (and the only spider found in the area which is dangerous to man) is the malmignatte or Mediterranean black widow. This spider, which belongs in the genus Latrodectus, is a close relative of the black widow and redback spiders, and has a bite which is medically significant. However, the so-called tarantulas were fairly large, frequently visible (as is typical of wolf spiders), and thus drew more attention. These factors, combined with the belief in the fatality of tarantism, assured the other kind of spiders generally called tarantulas a fearsome reputation. When theraphosidae were encountered by European explorers in the Americas, they were named "tarantulas". Nevertheless, these spiders belong to the suborder Mygalomorphae, and are not at all closely related to wolf spiders. The name "tarantula" is also applied to other large-bodied spiders, including the purseweb spiders or atypical tarantulas, the funnel-web tarantulas (Dipluridae and Hexathelidae), and the dwarf tarantulas. These spiders are related to true tarantulas (all being mygalomorphs), but are classified in different families. See also | |||||||||||||||||||||||||||||||||||||||||||
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