Everything about Salticidae totally explained
The
jumping spider family (
Salticidae) contains more than 500 described genera and over 5,000
species, making it the largest family of
spiders with about 13% of all species (Peng
et al., 2002). Jumping spiders have good vision and use it for hunting and navigating. They are capable of jumping from place to place, secured by a
silk tether. Both their
book lungs and the tracheal system are well-developed, as they depend on both systems (bimodal breathing).
Habitat
Jumping spiders live in a variety of habitats.
Tropical forests harbor the most species, but they're also found in
temperate forests, scrub lands,
deserts, the
intertidal zone (in
Malaysia), even mountains
one species is reported to have been the spider collected at the highest elevation, on the slopes of
Mt. Everest (Wanless, 1975). Certain species of Salticidae are quite common in Europe, such as the Zebra Jumping Spider
Salticus scenicus, which is commonly found resting on sun-warmed stone or brick walls.
Appearance
Jumping spiders are generally recognized by their
eye pattern. They typically have eight eyes arranged in two or three rows. The front, and most distinctive row is enlarged and forward facing to enable
stereoscopic vision. The others are situated back on the
cephalothorax.
Colours and patterns vary widely. Several species of jumping spiders appear to
mimic ants,
beetles, or
pseudoscorpions. Others may appear to be parts of
grass stems, bumps on twigs, bark, part of a rock or even part of a sand surface.
Behavior
Jumping spiders are generally
diurnal, active hunters. Their well developed internal
hydraulic system extends their limbs by altering the pressure of body fluid (blood) within them. This enables the spiders to jump without having large muscular legs like a
grasshopper. The jumping spider can therefore jump 20 to 60 or even 80 times the length of their body. When a jumping spider is moving from place to place, and especially just before it jumps, it tethers a filament of silk to whatever it's standing on. Should it fall for one reason or another, it climbs back up the silk tether.
Unlike almost all other spiders, they can quite easily climb on glass. Minute hairs and claws on their feet enable them to grip imperfections in the glass.
Jumping spiders also use their silk to weave small tent-like dwellings where females can protect their
eggs, and which also serve as a shelter while
moulting.
Jumping spiders are known for their curiosity. If approached by a human hand, instead of scuttling away to safety as most spiders do, the jumping spider will usually leap and turn to face the hand. Further approach may result in the spider jumping backwards while still eyeing the hand. The tiny creature will even raise its forelimbs and "hold its ground." Because of this contrast to other arachnids, the jumping spider is regarded as
inquisitive as it's seemingly interested in whatever approaches it.
Vision
Jumping spiders have very good
vision centered in their median eyes (AME). Their eyes are able to create a focused image on the retina, which has up to four layers of receptor cells in it (Harland & Jackson, 2000). Physiological experiments have shown that they may have up to four different kinds of receptor cells, with different
absorption spectra, giving them the possibility of up to
tetrachromatic
color vision, with sensitivity extending into the
ultra-violet range. It seems that all salticids, regardless of whether they've two, three or four kinds of color receptors, are highly sensitive to
UV light (Peaslee & Wilson, 1989). Some species (for example,
Cosmophasis umbratica) are highly
dimorphic in the UV spectrum, suggesting a role in sexual signaling (Lim & Li, 2005). Color discrimination has been demonstrated in behavioral experiments.
The principal eyes have high resolution (11 min. visual angle)
(External Link
), but the field of vision is narrow, from 2-5 degrees.
Because the retina is the darkest part of the eye and it moves around, one can sometimes look into the eye of a jumping spider and see it changing color. When it's darkest, you're looking into its retina and the spider is looking straight at you.
(External Link)
Diet
Hunting
Jumping spiders capture their prey by jumping on it from several inches away, and they may jump from twig to twig or leaf to leaf. They can jump many times their body length. They can carry out complex maneuvers such as detours around obstacles in order to reach their prey. Their eyesight is much better than the other spiders and most, if not all, insects. Most other spiders will only eat prey that they've captured live because they're unable to see dead prey (some
long-legged sac spiders and
anyphaenid sac spiders are exceptions as they recognize insect eggs as food) but jumping spiders will eat flies that have been killed for them. One jumping spider (
Evarcha culicivora) is even known to only capture
mosquitos full of blood, using their eyesight and smell.
Nectar and pollen
Even if there are no spiders that are pure
herbivores, there are some jumping spiders which include
nectar and
pollen in their diet (Jackson
et al., 2001). So far none are known to feed on seeds. When insects land on plants such as the partridge pea, which offers the spiders nectar through their extrafloral nectaries, the jumping spiders help protect the plant in return by killing and eating insects that might damage the plant.
Gliding
At least one species of jumping spiders, known as the Gliding Spider (
Maratus volans) from
Australia, has an abdomen with two wing-like flaps that can be tucked underneath it when not in use. When the spider is leaping, it can use its flaps to extend the jump and glide short distances through the air.
Venom
Some jumping spiders may bite to protect themselves if disturbed. However, jumping spiders usually escape and hide, and will only bite if provoked and cornered. While the bite of a larger jumping spider can be painful, only a few species produce any other effects. Almost all spiders (except
hackled orb-weavers) have venom, but the
venom of most spiders is no worse than the venom of a
bee.
Reproduction
Jumping spiders use their vision in complex visual courtship displays. Males are often quite different in appearance than females and may have plumose hairs, colored or metallic hairs, front leg fringes, structures on other legs and other, often bizarre, modifications. These are used in visual courtship in which the colored or metallic parts of the body are displayed and complex sideling, vibrational or zigzag movements are performed in a courtship "dance." A 2008 study of
Phintella vittatain in
Current Biology suggested that female spiders reacted to the male reflecting
ultraviolet B light before mating, a finding that challenges the previously held assumption that animals didn't register ultraviolet B light.
In recent years it has been discovered that many jumping spiders may have auditory signals as well, with amplified sounds produced by the males sounding like buzzes or drum rolls.
Gallery
Image:Blck&whte jumpingspider WA.jpg|Salticus scenicus
Image:Saitis.barbipes.male.waving.jpg|male Saitis barbipes
Image:Phidippus_audax3.JPG|Phidippus audax
Image:Phidippus_workmani_dorsal.jpg|Phidippus workmani
Image:Marpissa muscosa front (aka).jpg|Marpissa muscosa
Image:JumpingSpider.jpg|Paraphidippus aurantius
Image:Ant Mimic Spider.jpg|ant mimic spider
image:Salticidae_Eris_sp.jpg|Eris species
Image:Plexippus setipes(Male).jpg|male Plexippus setipes
Image:Phidippus mystaceus.jpg|Female Phidippus mystaceus
Image:meta undata2.jpg|Metacyrba undata
Image:Holoplatys semiplanata.jpg|Holoplatys semiplanata
Image:JumpingSpiderFront.JPG|unknown
Image:JumpingSpiderSide.JPG|Juvenile Phiddipus audax
image:Jumping_spider_hood_of_truck.jpg|Probably Phidippus sp.
Image:Spider_eating_fly_closer.jpg|Mopsus mormon Devouring a fly
Further Information
Get more info on 'Salticidae'.
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