129-407: Tarantulas comprise a group of large and often hairy spiders of the family Theraphosidae . As of December 2023, 1,100 species have been identified, with 166 genera . The term "tarantula" is usually used to describe members of the family Theraphosidae, although many other members of the same infraorder ( Mygalomorphae ) are commonly referred to as "tarantulas" or "false tarantulas". Some of
258-530: A cribellum , a modified spinneret with up to 40,000 spigots, each of which produces a single very fine fiber. The fibers are pulled out by the calamistrum , a comblike set of bristles on the jointed tip of the cribellum, and combined into a composite woolly thread that is very effective in snagging the bristles of insects. The earliest spiders had cribella, which produced the first silk capable of capturing insects, before spiders developed silk coated with sticky droplets. However, most modern groups of spiders have lost
387-467: A mutualistic relationship with a species of ant . Juveniles of some spiders in the families Anyphaenidae , Corinnidae , Clubionidae , Thomisidae and Salticidae feed on plant nectar . Laboratory studies show that they do so deliberately and over extended periods, and periodically clean themselves while feeding. These spiders also prefer sugar solutions to plain water, which indicates that they are seeking nutrients. Since many spiders are nocturnal,
516-406: A tracheal system, or both. Mygalomorph and Mesothelae spiders have two pairs of book lungs filled with haemolymph, where openings on the ventral surface of the abdomen allow air to enter and diffuse oxygen . This is also the case for some basal araneomorph spiders, like the family Hypochilidae , but the remaining members of this group have just the anterior pair of book lungs intact while
645-493: A better chance of survival if they have the opportunity to eat pollen. In captivity, several spider species are also known to feed on bananas , marmalade , milk , egg yolk and sausages . Airborne fungal spores caught on the webs of orb-weavers may be ingested along with the old web before construction of a new web. The enzyme chitinase present in their digestive fluid allows for the digestion of these spores. Spiders have been observed to consume plant material belonging to
774-412: A combination of lightness, strength and elasticity superior to synthetic materials, and spider silk genes have been inserted into mammals and plants to see if these can be used as silk factories. As a result of their wide range of behaviors, spiders have become common symbols in art and mythology , symbolizing various combinations of patience, cruelty and creative powers. An irrational fear of spiders
903-419: 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. In some cases, tarantula bristles have caused permanent damage to human eyes. Some setae are used to stridulate , which makes a hissing sound. These bristles are usually found on
1032-402: A dry material. Malphigian tubules ("little tubes") extract these wastes from the blood in the hemocoel and dump them into the cloacal chamber, from which they are expelled through the anus . Production of uric acid and its removal via Malphigian tubules are a water-conserving feature that has evolved independently in several arthropod lineages that can live far away from water, for example
1161-454: A female mate. Although females continue to molt after reaching maturity, males rarely do again once they reach adulthood. Those that do often can become stuck during the molting process due to their sexual organs and die. Females can live for 30 to 40 years. Grammostola rosea spiders, which eat once or twice a week, have lived up to 20 years in captivity. Some have survived on water alone for up to two years. After reaching sexual maturity,
1290-481: A female tarantula normally mates and lays eggs once per year, although they do not always do so. As with other spiders, the mechanics of intercourse are quite different from those of mammals . Once a male spider reaches maturity and becomes motivated to mate, he weaves a web mat on a flat surface. The spider then rubs his abdomen on the surface of this mat, and in so doing, releases a quantity of semen. He may then insert his pedipalps (short, leg-like appendages between
1419-467: A few to 50,000 individuals. Social behavior ranges from precarious toleration, as in the widow spiders , to cooperative hunting and food-sharing. Although most spiders live for at most two years, tarantulas and other mygalomorph spiders can live up to 25 years in captivity. While the venom of a few species is dangerous to humans, scientists are now researching the use of spider venom in medicine and as non-polluting pesticides . Spider silk provides
SECTION 10
#17327806844531548-424: A foot of sorts); the tarsus ends in a claw made up of either two or three points, depending on the family to which the spider belongs. Although all arthropods use muscles attached to the inside of the exoskeleton to flex their limbs, spiders and a few other groups still use hydraulic pressure to extend them, a system inherited from their pre-arthropod ancestors. The only extensor muscles in spider legs are located in
1677-706: A large variety of taxa and type. Conversely, cursorial spiders comprise the vast majority (over 80%) of reported incidents of plant-eating. The best-known method of prey capture is by means of sticky webs. Varying placement of webs allows different species of spider to trap different insects in the same area, for example flat horizontal webs trap insects that fly up from vegetation underneath while flat vertical webs trap insects in horizontal flight. Web-building spiders have poor vision, but are extremely sensitive to vibrations. The water spider Argyroneta aquatica build underwater "diving bell" webs that they fill with air and use for digesting prey and molting. Mating and raising
1806-486: A maximum of 4 cm ( 1 + 1 ⁄ 2 in). Theraphosa apophysis (the pinkfoot goliath) was described 187 years after the goliath birdeater, so its characteristics are not as well attested. T. blondi is generally thought to be the heaviest tarantula, and T. apophysis has the greatest leg span. Two other species, Lasiodora parahybana (the Brazilian salmon birdeater) and Lasiodora klugi , rival
1935-493: A pair of nerve cords running below the gut, with paired ganglia as local control centers in all segments; a brain formed by fusion of the ganglia for the head segments ahead of and behind the mouth, so that the esophagus is encircled by this conglomeration of ganglia. Except for the primitive Mesothelae , of which the Liphistiidae are the sole surviving family, spiders have the much more centralized nervous system that
2064-462: A period of several days; the venom of the African tarantula Pelinobius muticus also causes strong hallucinations. For Poecilotheria species, researchers have described more than 20 bites with the delayed onset of severe and diffuse muscle cramps, lasting for several days, that in most cases resolved completely with the use of benzodiazepines and magnesium . In all cases, seeking medical aid
2193-464: A postultimate molt , which is unlikely in natural habitats because they are vulnerable to predation, but has happened in captivity, though rarely. Most males do not live through this molt , as they tend to get their emboli, mature male sexual organs on pedipalps , stuck in the molt . Most tarantula fanciers regard females as more desirable as pets due to their much longer lifespans. Wild-caught tarantulas are often mature males because they wander out in
2322-469: A reduced number of eyes, the most common having six eyes (example, Periegops suterii ) with a pair of eyes absent on the anterior median line . Other species have four eyes and members of the Caponiidae family can have as few as two. Cave dwelling species have no eyes, or possess vestigial eyes incapable of sight. As with other arthropods, spiders' cuticles would block out information about
2451-509: A single genus, Aranea . In 1802, Charles Athanase Walckenaer separated mygalomorph spiders into a separate genus, Mygale , leaving all other spiders in Aranea . However, Mygale had already been used in 1800 by Georges Cuvier for a genus of mammals (in Greek , mygale means " shrew "). Accordingly, in 1869, Tamerlan Thorell used the family name "Theraphosoidae" (modern Theraphosidae) for
2580-440: A single one in the middle, and moved backwards close to the spinnerets . Spiders that have tracheae generally have higher metabolic rates and better water conservation. Spiders are ectotherms , so environmental temperatures affect their activity. Uniquely among chelicerates , the final sections of spiders' chelicerae are fangs, and the great majority of spiders can use them to inject venom into prey from venom glands in
2709-476: A small cylindrical section, the pedicel. The pattern of segment fusion that forms chelicerates' heads is unique among arthropods, and what would normally be the first head segment disappears at an early stage of development, so that chelicerates lack the antennae typical of most arthropods. In fact, chelicerates' only appendages ahead of the mouth are a pair of chelicerae , and they lack anything that would function directly as "jaws". The first appendages behind
SECTION 20
#17327806844532838-619: A species of wolf spider native to Mediterranean Europe. The name is derived from the southern Italian town of Taranto . The term tarantula was subsequently applied to almost any large, unfamiliar species of ground-dwelling spider, in particular to the Mygalomorphae and especially the New World Theraphosidae . Compared to tarantulas, wolf spiders are not particularly large or hairy, and so among English speakers in particular, usage eventually shifted in favour of
2967-409: A spider consists of seven distinct parts. The part closest to and attaching the leg to the cephalothorax is the coxa ; the next segment is the short trochanter that works as a hinge for the following long segment, the femur ; next is the spider's knee, the patella , which acts as the hinge for the tibia ; the metatarsus is next, and it connects the tibia to the tarsus (which may be thought of as
3096-410: A tarantula may signal its intention to attack by rearing up into a "threat posture", which may involve raising its prosoma and lifting its front legs into the air, spreading and extending its fangs, and (in certain species) making a loud hissing by stridulating . Tarantulas often hold this position for longer than the duration of the original threat. Their next step, without biting, may be to slap down on
3225-400: Is a long, slender tube located along the top of the opisthosoma . The heart is neurogenic as opposed to myogenic, so nerve cells instead of muscle cells initiate and coordinate the heart. It pumps hemolymph to all parts of the body through open passages often referred to as sinuses, and not through a circular system of blood vessels. If the exoskeleton is breached, loss of hemolymph will kill
3354-400: Is accomplished by coating the prey with digestive juices secreted from openings in the chelicerae . The tarantula's digestive organ (stomach) is a tube that runs the length of its body. In the prosoma , this tube is wider and forms the sucking stomach. When the sucking stomach's powerful muscles contract, the stomach is increased in cross-section, creating a strong sucking action that permits
3483-400: Is advised. 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. Such allergic effects can be life-threatening. Additionally, the large fangs of a tarantula can inflict painful puncture wounds , which can lead to secondary bacterial infections if not properly treated. Before biting,
3612-571: Is called arachnophobia . The word spider derives from Proto-Germanic * spin-þron- , literally ' spinner ' (a reference to how spiders make their webs), from the Proto-Indo-European root * (s)pen- ' to draw, stretch, spin ' . Spiders are chelicerates and therefore, arthropods . As arthropods, they have: segmented bodies with jointed limbs, all covered in a cuticle made of chitin and proteins; heads that are composed of several segments that fuse during
3741-479: Is determined by measuring from the tip of the back leg to the tip of the front leg on the opposite side. Some of the largest species of tarantula may weigh over 85 g (3 oz); the largest of all, the goliath birdeater ( Theraphosa blondi ) from Venezuela and Brazil , has been reported to attain a weight of 170 g (6 oz) and a leg-span up to 30 cm (12 in), males being longer and females greater in girth. The fang size of this tarantula reaches
3870-493: Is exuded. As the silk is pulled out of the spinnerets, the shear forces cause proteins in the silk to crystallize, transforming it from a liquid to a solid thread. The tarantula's mouth is located under its chelicerae on the lower front part of its prosoma . The mouth is a short, straw-shaped opening that can only suck, meaning that anything taken into it must be in liquid form. Prey with large amounts of solid parts, such as mice, must be crushed and ground up or predigested, which
3999-516: Is fairly large (4- to 5-inch legspan), somewhat ″hairy″, and is highly venomous to humans. Another dangerous type of spiders that have been confused with tarantulas are the Australian funnel-web spiders . The best known species of these is the Sydney funnel-web spider ( Atrax robustus ) a spider that is aggressive, highly venomous , and (prior to the development of antivenom in the 1980s)
Tarantula - Misplaced Pages Continue
4128-847: Is highlighted. Spider See Spider taxonomy . Spiders ( order Araneae ) are air-breathing arthropods that have eight limbs, chelicerae with fangs generally able to inject venom , and spinnerets that extrude silk . They are the largest order of arachnids and rank seventh in total species diversity among all orders of organisms . Spiders are found worldwide on every continent except Antarctica , and have become established in nearly every land habitat . As of September 2024 , 52,309 spider species in 134 families have been recorded by taxonomists . However, there has been debate among scientists about how families should be classified, with over 20 different classifications proposed since 1900. Anatomically , spiders (as with all arachnids) differ from other arthropods in that
4257-481: Is imminent when the exoskeleton takes on a darker shade. If a tarantula previously used its urticating hairs, the bald patch turns from a peach color to deep blue. The tarantula also stops feeding and becomes more lethargic during this time. While most Tarantulas species take between two and five years to reach sexual maturity, some species can take up to 10 years. Upon reaching adulthood, males typically have an 18-month period left to live so immediately go in search of
4386-468: Is mainly composed of a protein very similar to that used in insect silk. It is initially a liquid, and hardens not by exposure to air but as a result of being drawn out, which changes the internal structure of the protein. It is similar in tensile strength to nylon and biological materials such as chitin , collagen and cellulose , but is much more elastic . In other words, it can stretch much further before breaking or losing shape. Some spiders have
4515-408: Is often made without identifying a particular spider, although the "banana tarantula" is sometimes named. A likely candidate for the true identity of this spider is the dangerous Brazilian wandering spider ( Phoneutria fera ) of the family Ctenidae , as it is sometimes found hiding in clusters of bananas and is one of several spiders called "banana spiders". It is not technically a tarantula, but it
4644-569: Is originally an end-product of protein metabolism, its excretion can be blocked in spiders, leading to an increase in its storage. Structural colors occur in some species, which are the result of the diffraction, scattering or interference of light, for example by modified setae or scales. The white prosoma of Argiope results from bristles reflecting the light, Lycosa and Josa both have areas of modified cuticle that act as light reflectors. The peacock spiders of Australia (genus Maratus ) are notable for their bright structural colours in
4773-401: Is soft and egg-shaped. It shows no sign of segmentation, except that the primitive Mesothelae , whose living members are the Liphistiidae , have segmented plates on the upper surface. Like other arthropods, spiders are coelomates in which the coelom is reduced to small areas around the reproductive and excretory systems. Its place is largely taken by a hemocoel , a cavity that runs most of
4902-486: Is successful, the male injects his sperm from the palpal bulbs into the female via one or two openings on the underside of her abdomen. Female spiders' reproductive tracts are arranged in one of two ways. The ancestral arrangement ("haplogyne" or "non-entelegyne") consists of a single genital opening, leading to two seminal receptacles (spermathecae) in which females store sperm. In the more advanced arrangement ("entelegyne"), there are two further openings leading directly to
5031-527: Is taken into the blood stream through the blood vessels in the lungs. Needed moisture may also be absorbed from humid air by these organs. A tarantula's blood is unique (not only in appearance); an oxygen-transporting protein is present (the copper-based hemocyanin ), but not enclosed in blood cells such as the erythrocytes of mammals. A tarantula's blood is not true blood, but rather a liquid called hemolymph (or haemolymph). At least four types of hemocytes , or hemolymph cells, are known. The tarantula's heart
5160-482: Is typical of arachnids: all the ganglia of all segments behind the esophagus are fused, so that the cephalothorax is largely filled with nervous tissue and there are no ganglia in the abdomen; in the Mesothelae, the ganglia of the abdomen and the rear part of the cephalothorax remain unfused. Despite the relatively small central nervous system, some spiders (like Portia ) exhibit complex behaviour, including
5289-415: Is up. Arthropods' proprioceptors , sensors that report the force exerted by muscles and the degree of bending in the body and joints, are well-understood. On the other hand, little is known about what other internal sensors spiders or other arthropods may have. Some spiders use their webs for hearing, where the giant webs function as extended and reconfigurable auditory sensors. Each of the eight legs of
Tarantula - Misplaced Pages Continue
5418-653: The Devonian period , about 386 million years ago , but these animals apparently lacked spinnerets. True spiders have been found in Carboniferous rocks from 318 to 299 million years ago and are very similar to the most primitive surviving suborder , the Mesothelae. The main groups of modern spiders, Mygalomorphae and Araneomorphae , first appeared in the Triassic period, more than 200 million years ago . The species Bagheera kiplingi
5547-649: The United States , Mexico , in Central America , and throughout South America . Other species occur variously throughout Africa , much of Asia (including the Ryukyu Islands in southern Japan ), and all of Australia . In Europe , some species occur in Spain , Portugal , Turkey , southern Italy , and Cyprus . Some genera of tarantulas hunt prey primarily in trees; others hunt on or near
5676-424: The chelicerae and front legs) into the pool of semen. The pedipalps absorb the semen and keep it viable until a mate can be found. When a male spider detects the presence of a female, the two exchange signals to establish that they are of the same species. These signals may also lull the female into a receptive state. If the female is receptive, then the male approaches her and inserts his pedipalps into an opening in
5805-401: The chelicerae as a pocket knife blade folds back into its handle. The chelicerae of a tarantula completely contain the venom glands and the muscles that surround them, and can cause the venom to be forcefully injected into prey. The pedipalpi are two six-segmented appendages connected to the prosoma near the mouth and protruding on either side of both chelicerae. In most species of tarantulas,
5934-644: The coati , kinkajou , and opossum in the New World , and mongooses and the honey badger in the Old World , are often immune to the venom of their arthropod prey. Humans also consume tarantulas for food in their native ranges. They are considered a delicacy in certain cultures (e.g. Venezuela and Cambodia). They can be roasted over an open fire to remove the bristles (described further below) and then eaten. Tarantulas have evolved specialized bristles, or setae , to defend themselves against predators. Besides
6063-629: The exocuticle of the legs and prosoma is modified by a tanning process, resulting in a brown coloration. Bilins are found, for example, in Micrommata virescens , resulting in its green color. Guanine is responsible for the white markings of the European garden spider Araneus diadematus . It is in many species accumulated in specialized cells called guanocytes . In genera such as Tetragnatha , Leucauge , Argyrodes or Theridiosoma , guanine creates their silvery appearance. While guanine
6192-499: The genus Tidarren amputate one of their palps before maturation and enter adult life with one palp only. The palps are 20% of the male's body mass in this species, and detaching one of the two improves mobility. In the Yemeni species Tidarren argo , the remaining palp is then torn off by the female. The separated palp remains attached to the female's epigynum for about four hours and apparently continues to function independently. In
6321-432: The mygalomorph spiders known to him, rather than "Mygalidae" (as used, for example, by John Blackwall ). Thorell later split the family into a number of genera, including Theraphosa . A 2019 phylogenomic study recognized 12 subfamilies, one (Ischnocolinae) known not to be monophyletic . The relationship between the subfamilies found in the study is shown in the following cladogram . The dual placing of Ischnocolinae
6450-489: The pampas , rainforest , desert , scrubland , mountains , and cloud forest . They are generally classed among the terrestrial types. They are burrowers that live in the ground. Tarantulas are becoming increasingly popular as pets and some species are readily available in captivity. Tarantulas can be confused with other members of the order Mygalomorphae , such as trapdoor spiders , funnel-web spiders and purseweb spiders . They can also be confused with some members of
6579-475: The prosoma (or cephalothorax) and the opisthosoma (or abdomen). The prosoma and opisthosoma are connected by the pedicel , or pregenital somite . This waist-like connecting piece is actually part of the prosoma and gives the opisthosoma a wide range of motion relative to the prosoma. Depending on the species, the body length of tarantulas ranges from about 5 to 11 cm (2 to 4 + 1 ⁄ 2 in) with leg spans of 8–30 cm (3–12 in). Leg span
SECTION 50
#17327806844536708-481: The thorax . Similarly, arguments can be formed against the use of the term "abdomen", as the opisthosoma of all spiders contains a heart and respiratory organs, organs atypical of an abdomen. Unlike insects , spiders do not have antennae . In all except the most primitive group, the Mesothelae , spiders have the most centralized nervous systems of all arthropods, as all their ganglia are fused into one mass in
6837-535: The Theraphosidae, even though they are not closely related to wolf spiders at all, being in a different infraorder . The name tarantula is also incorrectly applied to other large-bodied spiders, including the purseweb spiders or atypical tarantulas , the funnel-webs ( Dipluridae and Hexathelidae ), and the dwarf tarantulas . These spiders are related to tarantulas (all being mygalomorphs ) but fall into different families from them. Huntsman spiders of
6966-439: The abdomen against the target, like the genus Avicularia . These fine bristles are barbed and serve to irritate. They can be lethal to small animals such as rodents. Some people are sensitive to these bristles, and develop serious itching and rashes at the site. Exposure of the eyes and respiratory system to urticating hairs should be strictly avoided. Species with urticating hairs can kick these bristles off; they are flicked into
7095-463: The abdomen becomes green. Environmentally induced color changes may be morphological (occurring over several days) or physiological (occurring near instantly). Morphological changes require pigment synthesis and degradation. In contrast to this, physiological changes occur by changing the position of pigment-containing cells. An example of morphological color changes is background matching. Misumena vatia for instance can change its body color to match
7224-414: The ability to use a trial-and-error approach. Spiders have primarily four pairs of eyes on the top-front area of the cephalothorax, arranged in patterns that vary from one family to another. The principal pair at the front are of the type called pigment-cup ocelli ("little eyes"), which in most arthropods are only capable of detecting the direction from which light is coming, using the shadow cast by
7353-432: The active hunters have acute vision and hunters of the genus Portia show signs of intelligence in their choice of tactics and ability to develop new ones. Spiders' guts are too narrow to take solids, so they liquefy their food by flooding it with digestive enzymes . They also grind food with the bases of their pedipalps , as arachnids do not have the mandibles that crustaceans and insects have. To avoid being eaten by
7482-494: The air at a target using their back pairs of legs. Tarantulas also use these bristles for other purposes, such as to mark territory or to line their shelters (the latter such practice may discourage flies from feeding on the spiderlings). Urticating hairs do not grow back, but are replaced with each molt . The intensity, number, and flotation of the bristles depends on the species of tarantula. To predators and other enemies, these bristles can range from being lethal to simply being
7611-485: The case of a mature male. The sixth pair of appendages is the chelicerae and their attached fangs. When walking, a tarantula's first and third legs on one side move at the same time as the second and fourth legs on the other side of its body. The muscles in a tarantula's legs cause the legs to bend at the joints, but to extend a leg, the tarantula increases the pressure of haemolymph entering the leg. Tarantulas, like almost all other spiders, have their primary spinnerets at
7740-404: The cephalothorax acts as a pump that sends the food deeper into the digestive system. The midgut bears many digestive ceca , compartments with no other exit, that extract nutrients from the food; most are in the abdomen, which is dominated by the digestive system, but a few are found in the cephalothorax. Most spiders convert nitrogenous waste products into uric acid , which can be excreted as
7869-579: The cephalothorax. Unlike most arthropods, spiders have no extensor muscles in their limbs and instead extend them by hydraulic pressure. Their abdomens bear appendages, modified into spinnerets that extrude silk from up to six types of glands. Spider webs vary widely in size, shape and the amount of sticky thread used. It now appears that the spiral orb web may be one of the earliest forms, and spiders that produce tangled cobwebs are more abundant and diverse than orb-weaver spiders . Spider-like arachnids with silk-producing spigots ( Uraraneida ) appeared in
SECTION 60
#17327806844537998-558: The chelicerae. Stridulation seems to be more common in Old World species. All tarantulas are venomous. Although their venom is not deadly to humans, some bites cause serious discomfort that might persist for several days. In general, the effects of the bites of all kinds of tarantula 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 and to produce intense spasms that may recur over
8127-619: The cribellum. Even species that do not build webs to catch prey use silk in several ways: as wrappers for sperm and for fertilized eggs; as a " safety rope "; for nest-building; and as " parachutes " by the young of some species. Spiders reproduce sexually and fertilization is internal but indirect, in other words the sperm is not inserted into the female's body by the male's genitals but by an intermediate stage. Unlike many land-living arthropods , male spiders do not produce ready-made spermatophores (packages of sperm), but spin small sperm webs onto which they ejaculate and then transfer
8256-430: The development of the embryo . Being chelicerates, their bodies consist of two tagmata , sets of segments that serve similar functions: the foremost one, called the cephalothorax or prosoma , is a complete fusion of the segments that in an insect would form two separate tagmata, the head and thorax ; the rear tagma is called the abdomen or opisthosoma . In spiders, the cephalothorax and abdomen are connected by
8385-438: The element pelma appears to have become synonymous with 'theraphosid'. For example, the author of Cardiopelma writes, " Cardiopelma fait réference aux genitalia de la femelle qui évoquent la forme d'un Coeur " ('Cardiopelma refers to the female genitalia that evoke the shape of a heart'), with no reference to either 'footsole' or 'scopula'. Names interpreted in this way include: Tarantulas of various species occur throughout
8514-444: The end of the opisthosoma. Unlike most spider species in the infraorder Araneomorphae , which includes the majority of extant spider species, and most of which have six, tarantula species have two or four spinnerets. Spinnerets are flexible, tube-like structures from which the spider exudes its silk. The tip of each spinneret is called the spinning field. Each spinning field is covered by as many as 100 spinning tubes through which silk
8643-566: The extent of nectar consumption by spiders may have been underestimated. Nectar contains amino acids , lipids , vitamins and minerals in addition to sugars, and studies have shown that other spider species live longer when nectar is available. Feeding on nectar avoids the risks of struggles with prey, and the costs of producing venom and digestive enzymes. Various species are known to feed on dead arthropods (scavenging), web silk, and their own shed exoskeletons. Pollen caught in webs may also be eaten, and studies have shown that young spiders have
8772-472: The family Sparassidae have also been termed tarantulas because of their large size, when, in fact, they are not related. Instead, huntsman spiders belong to the infraorder Araneomorphae . Many theraphosid genera have names, either accepted or synonymous , containing the element pelma . This can be traced back to Carl Ludwig Koch in 1850, who in describing his new genus Eurypelma wrote, " Die Sammetbürste der Fussohlen sehr breit " ( lit. '
8901-406: The females stay very close to the egg sacs and become more aggressive. Within most species, the females turn the egg sac often, which is called brooding. This keeps the eggs from deforming due to sitting in one position too long. The young spiderlings remain in the nest for some time after hatching, where they live off the remains of their yolk sacs before dispersing. Linnaeus placed all spiders in
9030-501: The females, which are typically much larger, male spiders identify themselves as potential mates by a variety of complex courtship rituals. Males of most species survive a few matings, limited mainly by their short life spans. Females weave silk egg cases, each of which may contain hundreds of eggs. Females of many species care for their young, for example by carrying them around or by sharing food with them. A minority of species are social, building communal webs that may house anywhere from
9159-473: The first pair is located in a cavity inside the lower front part of the abdomen near where the abdomen connects to the cephalothorax , and the second pair is slightly farther back on the abdomen. Air enters the cavity through a tiny slit on each side of and near the front of the abdomen. Each lung consists of 15 or more thin sheets of folded tissue arranged like the pages of a book. These sheets of tissue are supplied by blood vessels. As air enters each lung, oxygen
9288-471: The foot', paralleling Koch's use of Fußsohle (in modern spelling). Thus Eurypelma literally means 'wide footsole'; however, arachnologists have conventionally taken pelma in such names to refer to the scopula, so producing the meaning 'with a wide scopula'. Other genus names or synonyms that Estrada-Alvarez and Cameron regard as having 'footsole' or 'scopula' meanings include: Later, particularly following genus names published by R.I. Pocock in 1901,
9417-400: The genus Pepsis , track, attack, and kill large tarantulas. They use olfaction to find the lair of a tarantula. The wasp must deliver a sting to the underside of the spider's cephalothorax, exploiting the thin membrane between the basal leg segments. This paralyzes the spider, and the wasp then drags it back into its burrow before depositing an egg on the prey's abdomen. The wasp then seals
9546-700: The ground. All tarantulas can produce silk ; while arboreal species typically reside in a silken "tube tent", terrestrial species line their burrows with silk to stabilize the burrow wall and facilitate climbing up and down. Tarantulas mainly eat large insects and other arthropods such as centipedes , millipedes , and other spiders , using ambush as their primary method of prey capture. Armed with their massive, powerful chelicerae tipped with long, chitinous fangs, tarantulas are well-adapted to killing other large arthropods . The biggest tarantulas sometimes kill and consume small vertebrates such as lizards , mice , bats , birds , and small snakes . The eight legs,
9675-598: The intruder with their raised front legs. If that response fails to deter the attacker, the tarantulas of the Americas may next turn away and flick urticating hairs toward the pursuing predator. The next response may be to leave the scene entirely, but especially if no line of retreat is available, their final response may also be to whirl suddenly and bite. Some tarantulas are well known to give "dry bites", i.e., they may defensively bite some animal that intrudes on their space and threatens them, but they do not pump venom into
9804-478: The large females from eating the small males before fertilization, except where the male is so much smaller that he is not worth eating. In web-weaving species, precise patterns of vibrations in the web are a major part of the rituals, while patterns of touches on the female's body are important in many spiders that hunt actively, and may "hypnotize" the female. Gestures and dances by the male are important for jumping spiders , which have excellent eyesight. If courtship
9933-406: The length of the body and through which blood flows. The heart is a tube in the upper part of the body, with a few ostia that act as non-return valves allowing blood to enter the heart from the hemocoel but prevent it from leaving before it reaches the front end. However, in spiders, it occupies only the upper part of the abdomen, and blood is discharged into the hemocoel by one artery that opens at
10062-418: The likely number of offspring by ensuring that the females are well-fed. However, males of most species survive a few matings, limited mainly by their short life spans. Some even live for a while in their mates' webs. Females lay up to 3,000 eggs in one or more silk egg sacs, which maintain a fairly constant humidity level. In some species, the females die afterwards, but females of other species protect
10191-423: The lower surface of her abdomen, the opisthosoma . After the semen has been transferred to the receptive female's body, the male swiftly leaves the scene before the female recovers her appetite. Although females may show some aggression after mating, the male rarely becomes a meal. Females deposit 50 to 2,000 eggs, depending on the species, in a silken egg sac and guard it for six to eight weeks. During this time,
10320-433: The males. While in many spiders color is fixed throughout their lifespan, in some groups, color may be variable in response to environmental and internal conditions. Choice of prey may be able to alter the color of spiders. For example, the abdomen of Theridion grallator will become orange if the spider ingests certain species of Diptera and adult Lepidoptera , but if it consumes Homoptera or larval Lepidoptera, then
10449-859: The males. Most spiders live for only one to two years, although some tarantulas can live in captivity for over 20 years, and an Australian female trapdoor spider was documented to have lived in the wild for 43 years, dying of a parasitic wasp attack. Spiders occur in a large range of sizes. The smallest, Patu digua from Colombia, are less than 0.37 mm (0.015 in) in body length. The largest and heaviest spiders occur among tarantulas , which can have body lengths up to 90 mm (3.5 in) and leg spans up to 250 mm (9.8 in). Only three classes of pigment ( ommochromes , bilins and guanine ) have been identified in spiders, although other pigments have been detected but not yet characterized. Melanins , carotenoids and pterins , very common in other animals, are apparently absent. In some species,
10578-462: The meantime, the female feeds on the palpless male. In over 60% of cases, the female of the Australian redback spider kills and eats the male after it inserts its second palp into the female's genital opening; in fact, the males co-operate by trying to impale themselves on the females' fangs. Observation shows that most male redbacks never get an opportunity to mate, and the "lucky" ones increase
10707-402: The midgut into the prey and then suck the liquified tissues of the prey into the gut, eventually leaving behind the empty husk of the prey. Others grind the prey to pulp using the chelicerae and the bases of the pedipalps , while flooding it with enzymes; in these species, the chelicerae and the bases of the pedipalps form a preoral cavity that holds the food they are processing. The stomach in
10836-419: The more common species have become popular in the exotic pet trade. Many New World species kept as pets have setae known as urticating hairs that can cause irritation to the skin, and in extreme cases, cause damage to the eyes. Like all arthropods , the tarantula is an invertebrate that relies on an exoskeleton for muscular support. Like other Arachnida , a tarantula's body comprises two main parts,
10965-404: The most decisive ways to tell is by looking at their fangs. Tarantula fangs face downwards, as opposed to those of true spiders , which face each other, allowing them to make pincerlike motions. They also own two book lungs , as opposed to true spiders which only have one. Their lifespan is also longer than most spiders. The spider originally bearing the name tarantula was Lycosa tarantula ,
11094-559: The mother's back, and females of some species respond to the "begging" behaviour of their young by giving them their prey, provided it is no longer struggling, or even regurgitate food. In one exceptional case, females of the jumping spider Toxeus magnus produce a nutritious milk-like substance for their offspring, and fed until they are sexually mature. Like other arthropods , spiders have to molt to grow as their cuticle ("skin") cannot stretch. In some species males mate with newly molted females, which are too weak to be dangerous to
11223-698: The mouth are called pedipalps , and serve different functions within different groups of chelicerates. Spiders and scorpions are members of one chelicerate group, the arachnids . Scorpions' chelicerae have three sections and are used in feeding. Spiders' chelicerae have two sections and terminate in fangs that are generally venomous , and fold away behind the upper sections while not in use. The upper sections generally have thick "beards" that filter solid lumps out of their food, as spiders can take only liquid food. Scorpions' pedipalps generally form large claws for capturing prey, while those of spiders are fairly small appendages whose bases also act as an extension of
11352-414: The mouth; in addition, those of male spiders have enlarged last sections used for sperm transfer. In spiders, the cephalothorax and abdomen are joined by a small, cylindrical pedicel, which enables the abdomen to move independently when producing silk . The upper surface of the cephalothorax is covered by a single, convex carapace , while the underside is covered by two rather flat plates. The abdomen
11481-638: The movements of its prey. A tarantula's setae are very sensitive organs and are used to sense chemical signatures, vibrations, wind direction, and possibly even sound. Tarantulas are also very responsive to the presence of certain chemicals such as pheromones . The eyes are located above the chelicerae on the forward part of the prosoma. They are small and usually set in two rows of four. Most tarantulas are not able to see much more than light, darkness, and motion. Arboreal tarantulas generally have better vision compared with terrestrial tarantulas. All types of tarantulas have two sets of book lungs (breathing organs);
11610-801: The mucous membranes of the nose. Some species have more effective urticating bristles than others. The goliath birdeater is known for its particularly irritating urticating bristles . They can penetrate the cornea , so eye protection should be worn when handling such tarantulas. Old World tarantulas have no urticating bristles and are more likely to attack when disturbed. They often have more potent, medically significant venom , and are faster and much more nervous and defensive than New World species. Some dangerous spider species are related to tarantulas and are frequently confused with them. A popular urban legend maintains that deadly varieties of tarantula exist somewhere in South America . This claim
11739-401: The normal bristles covering the body, some tarantulas also have a dense covering of irritating bristles called urticating hairs , on the opisthosoma , that they sometimes use as protection against enemies. These bristles are present on most New World species, but not on any specimens from the Old World. Urticating hairs are usually kicked off the abdomen by the tarantula, but some may simply rub
11868-414: The offspring happens in the female's bell. They live almost entirely within the bells, darting out to catch prey animals that touch the bell or the threads that anchor it. A few spiders use the surfaces of lakes and ponds as "webs", detecting trapped insects by the vibrations that these cause while struggling. Hemirrhagus 27, see text Hemirrhagus is a genus of Mexican tarantulas that
11997-407: The open and are more likely to be caught. Like other spiders, tarantulas have to shed their exoskeleton periodically as they grow, a process called molting . A young tarantula may do this several times a year as a part of the maturation process, while full-grown specimens only molt once a year or less, or sooner, to replace lost limbs or lost urticating hairs . It is visibly apparent that molting
12126-684: The order Araneomorphae such as the Lycosidae family. There are multiple ways to identify a tarantula. First the hairs: in the Americas most tarantulas have urticating hairs , though some, such as the Hemirrhagus genus, lack these. The hairs are usually more noticeable than with most other spiders . Another is the size, as tarantulas tend to be bigger, but this is again not a failproof way. They also do not use their webs for hunting, instead using them as building material or tripwire. One of
12255-522: The outside world, except that they are penetrated by many sensors or connections from sensors to the nervous system. In fact, spiders and other arthropods have modified their cuticles into elaborate arrays of sensors. Various touch sensors, mostly bristles called setae , respond to different levels of force, from strong contact to very weak air currents. Chemical sensors provide equivalents of taste and smell , often by means of setae. An adult Araneus may have up to 1,000 such chemosensitive setae, most on
12384-442: The ovarian cavity where fertilization occurs. The only known example of direct fertilization between male and female is an Israeli spider, Harpactea sadistica , which has evolved traumatic insemination . In this species the male will penetrate its pedipalps through the female's body wall and inject his sperm directly into her ovaries, where the embryos inside the fertilized eggs will start to develop before being laid. Males of
12513-413: The pedipalpi contain sharp, jagged plates used to cut and crush food often called the coxae or maxillae . As with other spiders, the terminal portions of the pedipalpi of males function as part of their reproductive system. Male spiders spin a silken platform (sperm web) on the ground onto which they release semen from glands in their opisthosoma . Then they insert their pedipalps into the semen, absorb
12642-442: The posterior pair of breathing organs are partly or fully modified into tracheae, through which oxygen is diffused into the haemolymph or directly to the tissue and organs. The tracheal system has most likely evolved in small ancestors to help resist desiccation . The trachea were originally connected to the surroundings through a pair of openings called spiracles , but in the majority of spiders this pair of spiracles has fused into
12771-551: The propulsive force for their jumps. Most spiders that hunt actively, rather than relying on webs, have dense tufts of fine bristles between the paired claws at the tips of their legs. These tufts, known as scopulae , consist of bristles whose ends are split into as many as 1,000 branches, and enable spiders with scopulae to walk up vertical glass and upside down on ceilings. It appears that scopulae get their grip from contact with extremely thin layers of water on surfaces. Spiders, like most other arachnids , keep at least four legs on
12900-445: The prosoma out are: coxa, trochanter, femur, patella, tibia, tarsus and pretarsus, and claw. Two or three retractable claws at the end of each leg are used to grip surfaces for climbing. Also on the end of each leg, surrounding the claws, is a group of bristles, called the scopula, which help the tarantula to grip better when climbing surfaces such as glass. The fifth pair is the pedipalps, which aid in feeling, gripping prey, and mating in
13029-413: The rear end of the abdomen and by branching arteries that pass through the pedicle and open into several parts of the cephalothorax. Hence spiders have open circulatory systems . The blood of many spiders that have book lungs contains the respiratory pigment hemocyanin to make oxygen transport more efficient. Spiders have developed several different respiratory anatomies, based on book lungs ,
13158-429: The roots of the chelicerae. The families Uloboridae and Holarchaeidae , and some Liphistiidae spiders, have lost their venom glands, and kill their prey with silk instead. Like most arachnids , including scorpions , spiders have a narrow gut that can only cope with liquid food and two sets of filters to keep solids out. They use one of two different systems of external digestion. Some pump digestive enzymes from
13287-417: The sacs by attaching them to their webs, hiding them in nests, carrying them in the chelicerae or attaching them to the spinnerets and dragging them along. Baby spiders pass all their larval stages inside the egg sac and emerge as spiderlings, very small and sexually immature but similar in shape to adults. Some spiders care for their young, for example a wolf spider 's brood clings to rough bristles on
13416-399: The same corner. A tarantula's central nervous system (brain) is located in the bottom of the inner prosoma . A tarantula perceives its surroundings primarily via sensory organs called setae (bristles or spines, sometimes referred to as hairs). Although a tarantula has eight eyes like most spiders , touch is its keenest sense, and in hunting, it primarily depends on vibrations given off by
13545-465: The secondary eyes are immobile. The visual acuity of some jumping spiders exceeds by a factor of ten that of dragonflies , which have by far the best vision among insects . This acuity is achieved by a telephotographic series of lenses, a four-layer retina, and the ability to swivel the eyes and integrate images from different stages in the scan. The downside is that the scanning and integrating processes are relatively slow. There are spiders with
13674-556: The semen into the pedipalps, and later insert the pedipalps (one at a time) into the reproductive organ of the female, which is located in her abdomen. The terminal segments of the pedipalps of male tarantulas are moderately larger in circumference than those of a female tarantula. Male tarantulas have special spinnerets surrounding the genital opening. Silk for the sperm web of the tarantula is exuded from these special spinnerets. A tarantula has four pairs of legs and two additional pairs of appendages. Each leg has seven segments, which from
13803-456: The sexes apart, it is assumed the blood scent is mixed with pheromones. Spiders also have in the joints of their limbs slit sensillae that detect force and vibrations. In web-building spiders, all these mechanical and chemical sensors are more important than the eyes, while the eyes are most important to spiders that hunt actively. Like most arthropods, spiders lack balance and acceleration sensors and rely on their eyes to tell them which way
13932-615: The shape of the male palpal bulb , and the urticating hairs on the abdomen are reduced or completely missing. It is the only genus with epigean, troglophile and troglobitic species. Hemirrhagus tarantulas are all found in Mexico all of them are largely distributed from Tamaulipas in the north to Chiapas in the south, primarily in the mountainous regions of Sierra Madre Oriental , Eje Volcánico Transversal , Sierra Norte de Oaxaca , and Sierra Madre Sur. All of this tarantulas are found in individual caves , some species living in
14061-464: The size of the two goliath spiders. Most species of North American tarantulas are brown. Elsewhere, species have been found that variously display cobalt blue ( Cyriopagopus lividus ), black with white stripes ( Aphonopelma seemanni ), yellow leg markings ( Eupalaestrus campestratus ), metallic blue legs with vibrant orange abdomen and green prosoma ( Chromatopelma cyaneopubescens ). Their natural habitats include savanna , grassland such as in
14190-570: The species Haplopelma lividum . Mature male tarantulas also may have tibial hooks on their front legs, which are used to restrain the female's fangs during copulation. Males typically have longer legs than the females. A juvenile male's sex can be determined by looking at a cast exuvia for epiandrous fusillae or spermathecae . Females possess spermathecae , except for the species Sickius longibulbi and Encyocratella olivacea . Males have much shorter lifespans than females because they die relatively soon after maturing. Few live long enough for
14319-457: The sperm to special syringe -styled structures, palpal bulbs or palpal organs, borne on the tips of the pedipalps of mature males. When a male detects signs of a female nearby he checks whether she is of the same species and whether she is ready to mate; for example in species that produce webs or "safety ropes", the male can identify the species and sex of these objects by "smell". Spiders generally use elaborate courtship rituals to prevent
14448-428: The spermathecae, creating a "flow through" system rather than a "first-in first-out" one. Eggs are as a general rule only fertilized during oviposition when the stored sperm is released from its chamber, rather than in the ovarian cavity. A few exceptions exist, such as Parasteatoda tepidariorum . In these species the female appears to be able to activate the dormant sperm before oviposition, allowing them to migrate to
14577-560: The spider in its burrow and flies off to search for more hosts. The wasp egg hatches into a larva and feeds on the spider's inessential parts, and as it approaches pupation, it consumes the remainder. Other arthropods, such as large scorpions and giant centipedes , are also known to prey on tarantulas. Tarantulas are also preyed upon by a wide variety of vertebrates. Many of these, including lizards, frogs, birds, snakes and mammals, are generalist predators of all kinds of large arthropods. Mammals that have been known to prey on tarantulas, such as
14706-428: The spider unless the wound is small enough that the hemolymph can dry and close it. Despite their large size and fearsome appearance and reputation, tarantulas themselves are prey for many other animals. The most specialized of these predators are large members of the wasp family Pompilidae such as the wasp Hemipepsis ustulata . These wasps are called " tarantula hawks ". The largest tarantula hawks, such as those in
14835-492: The substrate it lives on which makes it more difficult to be detected by prey. An example of physiological color change is observed in Cyrtophora cicatrosa , which can change its body color from white to brown near instantly. Although spiders are generally regarded as predatory, the jumping spider Bagheera kiplingi gets over 90% of its food from Beltian bodies , a solid plant material produced by acacias as part of
14964-440: The surface while walking or running. The abdomen has no appendages except those that have been modified to form one to four (usually three) pairs of short, movable spinnerets , which emit silk . Each spinneret has many spigots , each of which is connected to one silk gland . There are at least six types of silk gland, each producing a different type of silk. Spitting spiders also produce silk in modified venom glands. Silk
15093-414: The tapeta. On the other hand, the secondary eyes of jumping spiders have no tapeta. Other differences between the principal and secondary eyes are that the latter have rhabdomeres that point away from incoming light, just like in vertebrates, while the arrangement is the opposite in the former. The principal eyes are also the only ones with eye muscles, allowing them to move the retina. Having no muscles,
15222-430: The tarantula to suck its liquefied prey up through the mouth and into the intestines. Once the liquefied food enters the intestines, it is broken down into particles small enough to pass through the intestine walls into the hemolymph (blood stream), where it is distributed throughout the body. After feeding, the leftovers are formed into a small ball by the tarantula and thrown away. In a terrarium, they often put them into
15351-436: The tarsi of the first pair of legs. Males have more chemosensitive bristles on their pedipalps than females. They have been shown to be responsive to sex pheromones produced by females, both contact and air-borne. The jumping spider Evarcha culicivora uses the scent of blood from mammals and other vertebrates, which is obtained by capturing blood-filled mosquitoes , to attract the opposite sex. Because they are able to tell
15480-559: The three hip joints (bordering the coxa and the trochanter). As a result, a spider with a punctured cephalothorax cannot extend its legs, and the legs of dead spiders curl up. Spiders can generate pressures up to eight times their resting level to extend their legs, and jumping spiders can jump up to 50 times their own length by suddenly increasing the blood pressure in the third or fourth pair of legs. Although larger spiders use hydraulics to straighten their legs, unlike smaller jumping spiders they depend on their flexor muscles to generate
15609-401: The tubules of insects and arachnids develop from completely different parts of the embryo . However, a few primitive spiders, the suborder Mesothelae and infraorder Mygalomorphae , retain the ancestral arthropod nephridia ("little kidneys "), which use large amounts of water to excrete nitrogenous waste products as ammonia . The basic arthropod central nervous system consists of
15738-559: The two chelicerae with their fangs, and the pedipalps are attached to the prosoma . The chelicerae are two double-segmented appendages located just below the eyes and directly forward of the mouth. The chelicerae contain the venom glands that vent through the fangs. The fangs are hollow extensions of the chelicerae that inject venom into prey or animals that the tarantula bites in defense, and they are also used to masticate . These fangs are articulated so that they can extend downward and outward in preparation to bite or can fold back toward
15867-418: The usual body segments are fused into two tagmata , the cephalothorax or prosoma, and the opisthosoma , or abdomen, and joined by a small, cylindrical pedicel . However, as there is currently neither paleontological nor embryological evidence that spiders ever had a separate thorax-like division, there exists an argument against the validity of the term cephalothorax, which means fused cephalon (head) and
15996-517: The velvet-brush of the footsole very wide ' ). German arachnologists use the word Fuß to refer to the tarsus (the last article of a spider's leg). Translations of Sammetbürste into Latin use the word scopula . Hence in English arachnological terminology, Koch meant 'the scopula of the base of the tarsus very wide'. Eury- is derived from the Greek eurýs ( εὐρύϛ ), meaning 'wide', while pélma ( πέλμα ) means 'the sole of
16125-461: The walls of the cup. However, in spiders these eyes are capable of forming images. The other pairs, called secondary eyes, are thought to be derived from the compound eyes of the ancestral chelicerates , but no longer have the separate facets typical of compound eyes. Unlike the principal eyes, in many spiders these secondary eyes detect light reflected from a reflective tapetum lucidum , and wolf spiders can be spotted by torchlight reflected from
16254-492: The wound. New-world tarantulas—those indigenous to the Americas—have bites that generally pose little threat to humans (other than causing localized pain). Most of them are equipped with urticating hairs on their abdomens, and almost always throw these barbed bristles as the first line of defense. These bristles irritate sensitive areas of the body and especially seem to target curious animals that may sniff these bristles into
16383-497: Was described as herbivorous in 2008, but all other known species are predators , mostly preying on insects and other spiders, although a few large species also take birds and lizards. An estimated 25 million tons of spiders kill 400–800 million tons of prey every year. Spiders use numerous strategies to capture prey: trapping it in sticky webs, lassoing it with sticky bolas , mimicking the prey to avoid detection, or running it down. Most detect prey mainly by sensing vibrations, but
16512-416: Was first described by Eugène Louis Simon in 1903. It is considered a senior synonym of Spelopelma . Species of the genus Hemirrhagus are 5 to 12 cm long, usually black in colour, the urticating hairs on the opisthosoma are arranged in one dorsomedian patch, two dorsal paramedian patches, or two lateral patches. It is unique amongst the theraphosine genera because of the retrolateral coxal heels,
16641-675: Was responsible for numerous deaths in Australia . These spiders are members of the same infraorder as tarantulas, Mygalomorphae . Some Australians use the slang term "triantelope" (a corruption of the incorrect term tarantula, which is also used) for large, ″hairy″, and harmless members of the huntsman spider family, which are often found on interior household walls and in automobiles. Some tarantula species exhibit pronounced sexual dimorphism . Males tend to be smaller (especially their abdomens, which can appear quite narrow) and may be dull in color when compared to their female counterparts, as in
#452547