Portia labiata

Portia labiata

''Portia labiata'' is a jumping spider In the family Salticidae.
White-Mustached Portia - Portia labiata  Jumping Spider,Malaysia,Penang,Portia labiata,Spider,White-Mustached Portia

Appearance

As in most species of the genus, the bodies of female ''Portia labiata''s are 7 to 10 millimetres long and their carapaces are 2.8 to 3.8 millimetres long. Males' bodies are 5 to 7.5 millimetres long, with carapaces 2.4 to 3.3 millimetres long. The carapaces of females are orange-brown, slightly lighter around the eyes, where there are sooty streaks and sometimes a violet to green sheen in certain lights. There is a broad white moustache along the bottom of the carapace, and running back from each main eye is a ridge that looks like a horn. Females' chelicerae are dark orange-brown and decorated with sparse white hairs, which form bands near the carapaces. The abdomens of females are mottled brown and black, and bear hairs of gold, white and black, and there are tufts consisting of brown hairs tipped with white. The carapaces of males are orange-brown, slightly lighter around the eyes, and have brown-black hairs lying on the surface but with a white wedge-shape stripe from the highest point down to the back, and white bands just above the legs. Males' chelicerae are also orange-brown with brown-black markings. The abdomens of males are brown with lighter markings and with brown-black hairs lying on the surface, and a short band of white hairs. The legs of both sexes are dark brown, with light markings in the femora . All species of the genus ''Portia'' have elastic abdomens, so that those of both sexes can become almost spherical when well fed, and females' can stretch as much when producing eggs.
Spider  Fall,Geotagged,Hong Kong,Portia labiata,Spider,Tai Po,labiata

Distribution

It is found in Sri Lanka, India, southern China, Burma , Malaysia, Singapore, Java, Sumatra and the Philippines.
Spider  Fall,Geotagged,Hong Kong,Portia labiata,Spider,Tai Po,labiata

Behavior

The genus ''Portia'' has been called "Eight-legged Cats", as their hunting tactics are as versatile and adaptable as a lion's. All members of ''Portia'' have instinctive hunting tactics for their most common prey, but often can improvise by trial and error against unfamiliar prey or in unfamiliar situations, and then remember the new approach. While most jumping spiders prey mainly on insects and by active hunting, females of ''Portia'' also build webs to catch prey directly and sometimes join their own webs on to those of web-based spiders. Both females and males prefer web spiders as prey, followed by other jumping spiders, and finally insects. In all cases females are more effective predators than males.

Habitat

''P. labiata'' is found in Sri Lanka, India, southern China, Burma , Malaysia, Singapore, Java, Sumatra and the Philippines.

The populations of ''P. labiata'' in Los Baños and in Sagada, both in the Philippines, have different environments: Los Baños is a low-lying tropical rainforest where there are many species of spiders, some of which are especially dangerous to ''P. labiata''; and Sagada is at higher altitude, with pine-forest and fewer species of spiders, none of which are as dangerous to ''P. labiata''. The Los Baños variant has a slightly wider repertoire of tactics.

In the Philippines, ''P. labiata'' does not prey on ants, but is preyed on by the ants ''Oecophylla smaragdina'' and ''Odontomachus'' sp. , and a solitary ''Odontomachus'' has been seen attacking a ''P. labiata''. In a test the ant ''Diacamma vagans'' usually killed single-handed a ''P. labiata''.

Reproduction

Before courtship, a male ''Portia'' spins a small web between boughs or twigs, and he hangs under that and ejaculates on to it. He then soaks the semen into reservoirs on his pedipalps, which are larger than those of females.

Females of many spider species, including ''P. labiata'', emit volatile pheromones into the air, and these generally attract males from a distance. The silk draglines of female jumping spiders also contain pheromones, which stimulate males to court females and may give information about each female's status, for example whether the female is juvenile, subadult or mature.
Pheromones may help to find jumping spiders' nests, which are usually hidden under rocks or in rolled leaves, making them difficult to be seen.

''Portia''s sometimes use "propulsive displays", with which a member threatens a rival of the same species and sex, and unreceptive females also threaten males in this way. A propulsive display is a series of sudden, quick movements including striking, charging, ramming and leaps.

A laboratory test showed how males of ''P. labiata'' minimise the risk of meeting each other, by recognising fresh pieces with blotting paper, some containing their own silk draglines and some containing another male's. Males also were attracted by fresh blotting paper containing females' draglines, while females do not response to fresh blotting paper containing males' draglines. This suggested that the males usually search for females, rather than vice versa. Neither sex responded to one week-old blotting paper, irrespective of whether it contained males' or females' draglines. A similar series of tests showed that ''P. fimbriata'' from Queensland showed the same patterns of responses between the sexes.

Among ''P. labiata'' and some other ''Portia''s, when adults of the same species but opposite sexes recognise each other, they display at 10 to 30 centimetres. Males usually wait for 2 to 15 minutes before starting a display, but sometimes a female starts a display first.

A female ''P. labiata'' that sees a male may approach slowly or wait. The male then walks with erect and displaying by waving his legs and palps. If the female does not run away, she gives a propulsive display first. If the male stands his ground and she does not ran away or repeat the propulsive display, he approaches and, if she is mature, they copulate. If the female is sub-adult , a male may cohabit in the female's capture web. ''Portia''s usually mate on a web or on a dragline made by the female. ''P. labiata'' typically copulates for about 100 seconds, while other genera can take several minutes or even several hours.

Females of ''P. labiata'' and ''P. schultzi'' try to kill and eat their mates during or after copulation, by twisting and lunging. The males wait until the females have hunched their legs, making this attack less likely. Males also try to abseil from a silk thread to approach from above, but females may manoeuvre to get the higher position. If the female moves at all, the male leaps and runs away.

Before being mature enough to mate, females of ''P. labiata'' and also ''P. schultzi'' mimic adult females to attract males as prey.

''P. labiata'' females are extremely aggressive to other females, trying to invade and take over each other's webs, which often results in cannibalism. A laboratory test showed how they minimise the risk of meeting each other, by recognising pieces with blotting paper containing their own silk draglines and pieces contain other ''P. labiata'' females' draglines. If obstacles make it impossible to see whether the other is physically present, she avoids blotting paper containing the other's draglines, but moves with no constraint if she can see that the other female is not around. Draglines seem to act as territory marks, much as many mammals identify conspecifics by scent marking. ''P. labiata'' females also avoid rival females of higher fighting ability and spend more time around less powerful fighters. A laboratory test collected samples of the draglines of equal-sized females and then pitted some of them in contests. Other females avoided the draglines of the victors, and spent the majority of their time on draglines of the losers. Similar tests showed that females of ''P. fimbriata'' from Australia and ''P. schultzi'' from Kenya do not avoid draglines of a powerful fighter.

In ''P. labiata'' and in some other species, contests between males usually last only 5 to 10 seconds, and only their legs make contact.
Contests between ''Portia'' females are violent and embraces in ''P. labiata'' typically take 20 to 60 seconds. These occasionally include grappling that sometimes breaks a leg, but more usually one female lunges at the other. Sometimes one knocks the other on her back and the other may be killed and eaten if she does not right herself quickly and run way. If the loser has a nest, the winner takes over and eats any eggs there.

When hunting, mature females of ''P. labiata'', ''P. africana'', ''P. fimbriata'' and ''P. schultzi'' emit olfactory signals that reduce the risk that any other females, males or juveniles of the same species may contend for the same prey. The effect inhibits aggressive mimicry against a prey spider even if the prey spider is visible, and also if the prey is inhabiting any part of a web. If a female of one of these ''Portia''s smells a male of the same species, the female stimulates the males to court. These ''Portia'' species do not show this behaviour when they receive olfactory signals from members of other ''Portia'' species.

''P. labiata'' usually lays eggs on dead, brown leaves about 20 millimetres long, suspended near the top of its capture web, and then covers the eggs with a sheet of silk. If there is no dead leaf available, the female will make a small horizontal silk platform in the capture web, lay the eggs on it, and then cover the eggs.

''Portia'' females have never been seen eating their own eggs, but in nature females with eggs of their own have been seen eating eggs of other females of the same species. In a test, ''P. labiata'' females did not eat their eggs if the testers put them in other female's nests, showing that the test females could identify their own eggs, possibly by chemical means. When the test females and their eggs were restored to their own nests and other females' eggs were also placed in the same nest, the test females ate neither their own eggs nor the "foreign" ones. In nature a female is unlikely to find foreign eggs in her nest, and it might be safest for females to avoid any eggs in their own nests.

For moulting, all ''Portia''s spin a horizontal web whose diameter is about twice the spider's body length and is suspended only 1 to 4 millimetres below a leaf. The spider lies head down, and often slides down 20 to 30 millimetres during moulting. ''Portia''s spin a similar temporary web for resting.

References:

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Taxonomy
KingdomAnimalia
DivisionArthropoda
ClassArachnida
OrderAraneae
FamilySalticidae
GenusPortia
SpeciesP. labiata
Photographed in
Hong Kong
Malaysia