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Wide-Jawed Viciria

By melvynyeo
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Pretty jumping spider taken at night in Singapore forest.

Quote from en.wikipedia.org/wiki/Jumping_…

Jumping spiders are generally diurnal, active hunters. Their well-developed internal hydraulic system extends their limbs by altering the pressure of 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.[6] Should it fall, for example if the prey shakes it off, it climbs back up the silk tether. Some species, such as Portia, will 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.[20] 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 anterior median eyes 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.

There are, though, many variations on the theme and many surprising aspects. For one thing, 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.[20]

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.[20]

Some Salticidae specialise in particular classes of prey. Ants comprise one such class. 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 — Corythalia canosa for example, circles round to the front of the ant and grabs it over the back of its head. Such myrmecophagous species, however, will not necessarily refuse other prey items, and will 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 there is little competition from other predators, but it remains profitable to catch less hazardous prey when it presents itself.[20]

Some of the most surprising hunting behaviour occurs among the araneophagous Salticidae, and it varies greatly in method. Many of the spider-hunting species quite commonly will 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.[20]

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, on the other hand, largely capture moths in their webs. In their review of the ethology of Salticidae, Richman and Jackson speculate on whether such web building is a relic of the evolution of this family from web-building ancestors.[20]

In hunting, Salticidae also use their silk for 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 rapidly acting venom that gives the victim little time to react.[21] 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.
IMAGE DETAILS
Image size
960x640px 401.57 KB
Make
Canon
Model
Canon EOS 5D Mark II
Shutter Speed
1/160 second
Aperture
F/16.0
Focal Length
100 mm
ISO Speed
250
Date Taken
May 3, 2014, 11:29:12 PM
Sensor Size
6mm
Published:
© 2014 - 2020 melvynyeo
Comments14
anonymous's avatar
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4dojo's avatar
that thing looks other worldly
MiLOz32's avatar
MiLOz32Student Digital Artist
Cool picture...
Lunarsmith's avatar
LunarsmithHobbyist Traditional Artist
Ahahahaha

I think it wants a kiss!
TheDoorWithin's avatar
TheDoorWithinHobbyist Writer
lol, he looks slightly scared/surprised xDDD great shot.
Tortwag's avatar
TortwagStudent Digital Artist
OH MY GOD WHAT THE HECK IS THAT. Darn, you're a seriously good Photographer, this shot is AMAZING.
Crawdadbisc's avatar
CrawdadbiscHobbyist Photographer
Truly eye boggling! Love him
jtfoto's avatar
Amazing!
Mystressb's avatar
It looks like its trying to eat 2 tiny, plum-colored bananas at the same time.  XD
Vinyonga's avatar
VinyongaHobbyist Photographer
Wow! Again, did you use the flash?
Raptrax101's avatar
i llove jumping spiders!!! ther so cute!
khamal's avatar
khamalHobbyist General Artist
what a little cutie
MarcosRodriguez's avatar
MarcosRodriguezHobbyist Photographer
Hi, your wonderful work has been featured in the latest devPREMIUM's Weekly Macro Spotlight Vol. 119. Best regards!!
MarcosRodriguez, Curator of the Macro Gallery at devPREMIUM
:icondevpremium:
SnowInHades's avatar
SnowInHadesHobbyist General Artist
Stunning colours :nod:
RaymondEternal's avatar
RaymondEternalHobbyist General Artist
Awesome Spider , Very Nice Shot! :salute:
anonymous's avatar
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