Temporal range: Palaeogene–present
|Adult male Phidippus audax|
|Family:|| Salticidae |
|600+ genera, 5000+ species|
Jumping spiders are a group of spiders that constitute the family Salticidae. As of 2019, this family contained over 600 described genera and over 6000 described species,making it the largest family of spiders at 13% of all species. Jumping spiders have some of the best vision among arthropods and use it in courtship, hunting, and navigation. Although they normally move unobtrusively and fairly slowly, most species are capable of very agile jumps, notably when hunting, but sometimes in response to sudden threats or crossing long gaps. Both their book lungs and tracheal system are well-developed, and they use both systems (bimodal breathing). Jumping spiders are generally recognized by their eye pattern. All jumping spiders have four pairs of eyes, with the anterior median pair being particularly large.
Jumping spiders are among the easiest to distinguish from similar spider families because of the shape of the cephalothorax and their eye patterns. The families closest to Salticidae in general appearance are the Corinnidae (distinguished also by prominent spines on the back four legs), the Oxyopidae (the lynx spiders, distinguished by very prominent spines on all legs), and the Thomisidae (the crab spiders, distinguished by their front four legs, which are very long and powerful). None of these families however, have eyes that resemble those of the Salticidae. Conversely, the legs of jumping spiders are not covered with any very prominent spines. Their front four legs generally are larger than the hind four, but not as dramatically so as those of the crab spiders, nor are they held in the outstretched-arms attitude characteristic of the Thomisidae.In spite of the length of their front legs, Salticidae depend on their rear legs for jumping. The generally larger front legs are used partly to assist in grasping prey, and in some species, the front legs and pedipalps are used in species-recognition signalling.
The jumping spiders, unlike the other families, have faces that are roughly rectangular surfaces perpendicular to their direction of motion. In effect this means that their forward-looking, anterior eyes are on "flat faces", as shown in the photographs. Their eye pattern is the clearest single identifying characteristic. They have eight eyes, as illustrated.Most diagnostic are the front row of four eyes, in which the anterior median pair are more dramatically prominent than any other spider eyes apart from the posterior median eyes of the Deinopidae. There is, however, a radical functional difference between the major (AME) eyes of Salticidae and the major (PME) eyes of the Deinopidae; the large posterior eyes of Deinopidae are adapted mainly to vision in dim light, whereas the large anterior eyes of Salticidae are adapted to detailed, three-dimensional vision for purposes of estimating the range, direction, and nature of potential prey, permitting the spider to direct its attacking leaps with great precision. The anterior lateral eyes, though large, are smaller than the AME and provide a wider forward field of vision.
The rear row of four eyes may be described as strongly bent, or as being rearranged into two rows, with two large posterior lateral eyes being the furthest back. They serve for lateral vision. The posterior median eyes also have been shifted out laterally, almost as far as the posterior lateral eyes. They are usually much smaller than the posterior lateral eyes and there is doubt about whether they are at all functional in many species.
The body length of jumping spiders generally ranges from 1 to 25 mm (0.04–0.98 in). The largest is Hyllus giganteus, while other genera with relatively large species include Phidippus , Philaeus and Plexippus .
In addition to using their silk for safety lines while jumping, they also build silken "pup tents", where they take shelter from bad weather and sleep at night. They molt in these shelters, build and store egg cases in them, and also spend the winter in them.
Jumping spiders live in a variety of habitats. Tropical forests harbor the most species, but they are also found in temperate forests, scrubland, deserts, intertidal zones, and mountainous regions. Euophrys omnisuperstes is the species reported to have been collected at the highest elevation, on the slopes of Mount Everest.
Jumping spiders have four pairs of eyes; three secondary pairs that are fixed and a principal pair that is movable.
The posterior median eyes (PMEs) are vestigial in many species, but in some primitive subfamilies, they are comparable in size with the other secondary eyes and help to detect motion.While unable to form images, the reduced pair of eyes is thought to have a role similar to that of insect ocelli by receiving light from the sky. The photoreceptors in the other secondary pairs are almost exclusively green-sensitive, but the PMEs have two visual pigments different from those in all the other eyes, sensitive to blue and UV light.
The posterior lateral eyes (PLEs) are wide-angle motion detectors that sense motions from the side and behind. Combined with the other eyes, PLEs give the spider a near 360° view of the world.
The anterior lateral eyes (ALEs) have the best visual acuity of the secondary eyes.They are able to distinguish some details, as well, and without them, no "looming response" can be triggered by motion. Even with all the other pairs covered, jumping spiders in a study could still detect, stalk, and attack flies, using their ALEs only, which are also sufficiently widely spaced to provide stereoscopic vision.
The anterior median eyes (AMEs) have very good vision. This pair of eyes is built like a telescopic tube with a corneal lens in the front and a second lens in the back that focus images onto a four-layered retina, a narrow, boomerang-shaped strip oriented vertically.Physiological experiments have shown they may have up to four different kinds of receptor cells, with different absorption spectra, giving them the possibility of tetrachromatic color vision, with sensitivity extending into the ultraviolet (UV) range. As the eyes are too close together to allow depth perception, and the animals do not make use of motion parallax, they have evolved a method called image defocus, instead. Of the four photoreceptor layers in the retina, the two closest to the surface contain UV-sensitive pigments, while the two deepest contain green-sensitive pigments. The incoming green light is only focused on the deepest layer, while the other one receives defocused or fuzzy images. By measuring the amount of defocus from the fuzzy layer, calculating the distance to the objects in front of them is possible. In addition to receptor cells, red filters also have been detected, located in front of the cells that normally register green light. All salticids, regardless of whether they have two, three, or four kinds of color receptors, seemingly are highly sensitive to UV light. Some species (for example, Cosmophasis umbratica ) are highly dimorphic in the UV spectrum, suggesting a role in sexual signaling. Color discrimination has been demonstrated in behavioral experiments.
The principal, AMEs have high resolution (11 min visual angle),but the field of vision is narrow, from 2 to 5°. The central region of the retina, where acuity is highest, is no more than six or seven receptor rows wide. However, the eye can scan objects off the direct axis of vision. As the lens is attached to the carapace, the eye's scanning movements are restricted to its retina through a complicated pattern of translations and rotations. This dynamic adjustment is a means of compensation for the narrowness of the static field of vision. It is analogous to the way most primates move their eyes to focus images of interest onto their fovea centralis. Such movements within the jumping spider's eyes are visible from outside when the attention of the spider is directed to various targets.
Jumping spiders are generally diurnal, active hunters. Their well-developed internal hydraulic system extends their limbs by altering the pressure of their body fluid (hemolymph) within them. This enables the spiders to jump without having large muscular legs like a grasshopper. Most jumping spiders can jump several times the length of their bodies. When a jumping spider is moving from place to place, and especially just before it jumps, it tethers a filament of silk (or 'dragline') to whatever it is standing on to protect itself if the jump should fail.Should it fall, for example if the prey shakes it off, it climbs back up the silk tether. Some species, such as Portia, actually let themselves down to attack prey such as a web spider apparently secure in the middle of its web. Like many other spiders that leave practically continuous silk trails, jumping spiders impregnate the silk line with pheromones that play a role in social and reproductive communication, and possibly in navigation.
Certain species of jumping spiders have been shown by experiment to be capable of learning, recognizing, and remembering colors, and adapting their hunting behavior accordingly.
The hunting behaviour of the Salticidae is confusingly varied compared to that of most spiders in other families.Salticids hunt diurnally as a rule, which is consistent with their highly developed visual system. When it detects potential prey, a jumping spider typically begins orienting itself by swivelling its cephalothorax to bring the AMEs to bear. It then moves its abdomen into line with its cephalothorax. After that, it might spend some time inspecting the object of its attention and determining whether a camouflaged or doubtful item of prey is promising, before it starts to stalk slowly forward. When close enough, the spider pauses to attach a dragline, then springs onto the prey.
Many variations on the theme and many surprising aspects exist. For one, salticids do not necessarily follow a straight path in approaching prey. They may follow a circuitous course, sometimes even a course that takes the hunter through regions from which the prey is not visible. Such complex adaptive behaviour is hard to reconcile with an organism that has such a tiny brain, but some jumping spiders, in particular some species of Portia, can negotiate long detours from one bush down to the ground, then up the stem of another bush to capture a prey item on a particular leaf.Such behaviour still is the subject of research.
Some salticid species are continually on the move, stopping periodically to look around for prey, which they then stalk immediately. Others spend more time scanning their surroundings from one position, actively stalking any prey they detect. Members of the genus Phaeacius take that strategy to extremes; they sit on a tree trunk, facing downwards and rarely do any stalking, but simply lunge down on any prey items that pass close before them.
Some Salticidae specialise in particular classes of prey, such as ants. Most spiders, including most salticids, avoid worker ants, but several species not only eat them as a primary item in their diets, but also employ specialised attack techniques; Anasaitis canosa , for example, circles around to the front of the ant and grabs it over the back of its head. Such myrmecophagous species, however, do not necessarily refuse other prey items, and routinely catch flies and similar prey in the usual salticid fashion, without the special precautions they apply in hunting dangerous prey such as ants. Ants offer the advantages of being plentiful prey items for which little competition from other predators occurs, but catching less hazardous prey when it presents itself remains profitable.
Some of the most surprising hunting behaviours occur among the araneophagous Salticidae, and vary greatly in method. Many of the spider-hunting species quite commonly attack other spiders, whether fellow salticids or not, in the same way as any other prey, but some kinds resort to web invasion; nonspecialists such as Phidippus audax sometimes attack prey ensnared in webs, basically in acts of kleptoparasitism; sometimes they leap onto and eat the web occupant itself, or simply walk over the web for that purpose.
Salticidae in the genera Brettus , Cyrba , Gelotia , and Portia display more advanced web-invasion behavior. They slowly advance onto the web and vibrate the silk with their pedipalps and legs. In this respect, their behaviour resembles that of the Mimetidae, probably the most specialised of the araneophagous spider families. If the web occupant approaches in the manner appropriate to dealing with ensnared prey, the predator attacks.
The foregoing examples present the Salticidae as textbook examples of active hunters; they would hardly seem likely to build webs other than those used in reproductive activities, and in fact, most species really do not build webs to catch prey. However, exceptions occur, though even those that do build capture webs generally also go hunting like other salticids. Some Portia species, for example, spin capture webs that are functional, though not as impressive as some orb webs of the Araneidae; Portia webs are of an unusual funnel shape and apparently adapted to the capture of other spiders. Spartaeus species, though, largely capture moths in their webs. In their review of the ethology of the Salticidae, Richman and Jackson speculate on whether such web building is a relic of the evolution of this family from web-building ancestors.
In hunting, the Salticidae also use their silk as a tether to enable them to reach prey that otherwise would be inaccessible. For example, by advancing towards the prey to less than the jumping distance, then retreating and leaping in an arc at the end of the tether line, many species can leap onto prey on vertical or even on inverted surfaces, which of course in a gravitational field would not be possible without such a tether.
Having made contact with the prey, hunting Salticidae administer a bite to inject rapid-acting venom that gives the victim little time to react.In this respect, they resemble the Mimetidae and Thomisidae, families that ambush prey that often are larger than the predator, and they do so without securing the victim with silk; they accordingly must immobilise it immediately and their venom is adapted accordingly.
Although jumping spiders are generally carnivorous, many species have been known to include nectar in their diets,and one species, Bagheera kiplingi , feeds primarily on plant matter. None are known to feed on seeds or fruit. Extrafloral nectaries on plants, such as Chamaecrista fasciculata (partridge pea), provide jumping spiders with nectar; the plant benefits accordingly when the spiders prey on whatever pests they find.
The female of the Southeast Asian species Toxeus magnus feeds its offspring with a milky, nutritious fluid for the first 40 days of their lives. Female offspring are also allowed some milk after sexual maturity.
Jumping spiders conduct complex, visual courtship displays using both movements and physical bodily attributes. Unlike females, males possess plumose hairs, colored or iridescent hairs (particularly pronounced in the peacock spiders), front leg fringes, structures on other legs, and other, often bizarre, modifications. These characteristics are used in a courtship "dance" in which the colored or iridescent parts of the body are displayed. In addition to the display of colors, jumping spiders perform complex sliding, vibrational, or zigzag movements to attract females. Many males have auditory signals, as well. These amplified sounds presented to the females resemble buzzes or drum rolls.Species vary greatly in visual and vibratory components of courtship. Many species have patches of UV reflectance, which are exhibited in mature males. This visual component is used by some female jumping spiders for mate choice.
If receptive to the male, the female assumes a passive, crouching position. In some species, the female may also vibrate her palps or abdomen. The male then extends his front legs towards the female to touch her. If the female remains receptive, the male climbs on her back and inseminates her with his palps.
Maintaining colorful ornamentation may seem strictly beneficial to sexual selection, yet costs to maintain such distinguishing characteristics occur.While colorful or UV-reflecting individuals may attract more female spiders, it can also increase the risk of predation.
|Classification within the spiders (Araneae)|
The monophyly of the family Salticidae is well established through both phylogenetic and morphological analyses, but no consensus exists on what other group of spiders is most closely related to the jumping spiders. Suggested sister groups have included the oxyopids (lynx spiders), thomisids (crab spiders), clubionoids (sac spiders), and web-building spiders.A 2017 phylogenetic analysis suggests that the sister group may be the family Miturgidae.
The taxonomy within the jumping spider family was significantly revised in 2015. The family is now divided into seven subfamilies:
Of these subfamilies, the Salticinae are by far the largest, comprising over 90% of the known species of jumping spiders.
Some small insects are thought to have evolved an appearance or behavioural traits that resemble those of jumping spiders and this is suspected to prevent their predation, specifically from jumping spiders. Some examples appear to be provided by patterns on the wings of some tephritid flies,the nymph of a fulgorid and possibly some moths.
Very few jumping spider fossils have been found. Of those known, all are from Cenozoic era amber. The oldest fossils are from Baltic amber dating to the Eocene epoch, specifically, 54 to 42 million years ago. Other fossil jumping spiders have been found in Chiapan amber and Dominican amber.
Portia is a genus of jumping spider that feeds on other spiders. They are remarkable for their intelligent hunting behaviour, which suggests that they are capable of learning and problem solving, traits normally attributed to much larger animals.
The zebra spider is a common jumping spider of the Northern Hemisphere. Like other jumping spiders it does not build a web. It has a particularly large pair of forward facing eyes that help it to locate and stalk its prey before pouncing on it. Their common name refers to their vivid black-and-white colouration, whilst their scientific name derives from Salticus from the Latin for “dancing”, in reference to their agility, and the Greek scenicus, translating to “theatrical” or “of a decorative place,” in reference to the flashy, zebra-like coloration of the species.
Portia labiata is a jumping spider found in Sri Lanka, India, southern China, Burma (Myanmar), Malaysia, Singapore, Java, Sumatra and the Philippines. In this medium-sized jumping spider, the front part is orange-brown and the back part is brownish. The conspicuous main eyes provide vision more acute than a cat's during the day and 10 times more acute than a dragonfly's, and this is essential in P. labiata′s navigation, hunting and mating.
Ascyltus are a genus of jumping spiders in the family Salticidae that was first described by Ferdinand Anton Franz Karsch in 1878. As of 2019, this Genus contained 10 species. The Ascyltus spiders utilize their vision in courtship, hunting, and navigation. Ascyltus are typically large to medium sized Salticids and often move relatively slow. However, they are capable of agile jumps when moving, hunting, or to avoid predators. They have well developed book lungs and tracheal systems, and they are capable of utilizing both systems. Ascyltus have four pairs of eyes, with the anterior median pair being the most prominent. One distinguishable characteristic of the Ascyltus include their antero-lateral carapace, which is iridescently colored.
Cyrba is a genus of spiders in the family Salticidae. The genus was erected by Hippolyte Lucas in 1846.
Phaeacius is a spider genus of the family Salticidae, found in sub-tropical China and between India and the Malay Peninsula, including Sri Lanka, Sumatra and the Philippines. Although other spiders can jump, salticids including Phaeacius have significantly better vision than other spiders, and their main eyes are more acute in daylight than a cat's and 10 times more acute than a dragonfly's. The main eyes focus accurately on an object at distances from approximately 2 centimetres (0.79 in) to infinity, and in practice can see up to about 75 centimetres (30 in). They do not spin webs.
Zygoballus is a genus of jumping spiders found in North and South America.
The anatomy of spiders includes many characteristics shared with other arachnids. These characteristics include bodies divided into two tagmata, eight jointed legs, no wings or antennae, the presence of chelicerae and pedipalps, simple eyes, and an exoskeleton, which is periodically shed.
The Spartaeinae are a subfamily of the spider family Salticidae. The subfamily was established by Fred R. Wanless in 1984 to include the groups Boetheae, Cocaleae, Lineae, Codeteae and Cyrbeae, which in turn were defined by Eugène Simon.
Thrandina is a genus of jumping spiders, with three species found in Ecuador. It is unique among New World salticids in having strikingly large posterior median eyes.
Lyssomaninae is a subfamily of jumping spiders. It includes four genera, three from the New World.
Zygoballus sexpunctatus is a species of jumping spider which occurs in the southeastern United States where it can be found in a variety of grassy habitats. Adult spiders measure between 3 and 4.5 mm in length. The cephalothorax and abdomen are bronze to black in color, with reddish brown or yellowish legs. The male has distinctive enlarged chelicerae and front femora. Like many jumping spiders, Z. sexpunctatus males exhibit ritualized courtship and agonistic behavior.
Anasaitis canosa, previously of the genus Corythalia, is a small jumping spider that can typically be found atop leaf-litter or man-made structures such as fences and exterior walls. This species is more commonly known as the twin-flagged jumping spider due to the two pennant shaped markings on the dorsal side of the cephalothorax. Typical of the genus Anasaitis, this species has iridescent setae ("scales") which may appear white, green or pink which create the "flags" as well as patches on the male pedipalps used in courtship and intraspecific signaling. This species is roughly one centimeter in length and has a lifespan up to two years. A. canosa ranges from Mexico to South Carolina along the Gulf of Mexico.
Portia fimbriata, sometimes called the fringed jumping spider, is a jumping spider found in Australia and Southeast Asia. Adult females have bodies 6.8 to 10.5 millimetres long, while those of adult males are 5.2 to 6.5 millimetres long. Both sexes have a generally dark brown carapace, reddish brown chelicerae ("fangs"), a brown underside, dark brown palps with white hairs, and dark brown abdomens with white spots on the upper side. Both sexes have fine, faint markings and soft fringes of hair, and the legs are spindly and fringed. However, specimens from New Guinea and Indonesia have orange-brown carapaces and yellowish abdomens. In all species of the genus Portia, the abdomen distends when the spider is well fed or producing eggs.
Portia schultzi is a jumping spider which ranges from South Africa in the south to Kenya in the north, and also is found in West Africa and Madagascar. In this species, which is slightly smaller than some other species of the genus Portia, the bodies of females are 5 to 7 mm long, while those of males are 4 to 6 mm long. The carapaces of both sexes are orange-brown with dark brown mottling, and covered with dark brown and whitish hairs lying over the surface. Males have white tufts on their thoraces and a broad white band above the bases of the legs, and these features are less conspicuous in females. Both sexes have tufts of orange to dark orange above the eyes, which are fringed with pale orange hairs. Males' abdomens are yellow-orange to orange-brown with blackish mottling, and on the upper sides are black and light orange hairs, and nine white tufts. Those of females are pale yellow and have black markings with scattered white and orange-brown hairs on the upper side. P. schultzi has relatively longer legs than other Portia, and a "lolloping" gait.
Portia africana is a jumping spider found in Angola, Cameroon, the Central African Republic, Gabon, Ghana, the Ivory Coast, Sierra Leone, Zaire and Zambia. Its conspicuous main eyes provide vision more acute than a cat's during the day and 10 times more acute than a dragonfly's, and this is essential in P. africana′s navigation, hunting and mating.
Seothyra, commonly known as the buckspoor spiders, buck spoor spiders or just spoor spiders, belong to a sand-dwelling, burrowing genus of araneomorph spiders in the family Eresidae. The 13 species are endemic to the arid, sandy flats and semistabilized red dunes of southern Africa. They are sexually dimorphic. The tiny males, which are seldom seen, imitate sugar ants or velvet ants in their appearance and habits, while the females hide in and hunt from their characteristic burrows. They are thermophilous, with males as well as females being most active on hot days.
Lyssomanes viridis, commonly known as the magnolia green jumper, is a species of jumping spider of the genus Lyssomanes, for which it is the type species. The species is native to the United States, being found in much of the Southeastern United States and Texas. It has also been reported from parts of Mexico, with sightings as far south as Guatemala and as far north as Delaware.
Asemoneinae is a subfamily of jumping spiders. It was created in 2015 by Wayne Maddison. Most species are found in Africa or Asia. The subfamily initially had five genera, but Hindumanes was later transferred to the subfamily Lyssomaninae.
Hisponinae is a subfamily of jumping spiders. The subfamily has six known extant genera and three extinct genera.
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