Portia fimbriata facts for kids
Quick facts for kids Portia fimbriata |
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Portia fimbriata, sometimes called the fringed jumping spider, is a jumping spider (family Salticidae) found in Australia and Southeast Asia.
Description
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.
Behavior
Hunting
The hunting tactics of Portia are versatile and adaptable. All members of Portia have instinctive hunting tactics for their most common prey, but can improvise by trial and error against unfamiliar prey or in unfamiliar situations, and then remember the new approach.
There are differences in the hunting tactics of the regional populations of P. fimbriata. Those in Australia's Northern Territory are poor at hunting jumping spiders and better against non-salticid web-building spiders and against insects. The Sri Lanka variant is fair against other jumping spiders, and good against web spiders and insects. P. fimbriata in Queensland is an outstanding predator of other jumping spiders and of web spiders, but poor against insects. The Queensland variant use a unique "cryptic stalking" technique which prevents most jumping spider prey from identifying this P. fimbriata as a predator, or even as an animal at all. Some jumping spider prey have partial defences against the cryptic stalking technique. All types of prey spiders occasionally counter-attack, but all Portia species have very good defences, starting with especially tough skin.
Mating
When meeting another of the same species, P. fimbriata does not use cryptic stalking but displays by moving quickly and smoothly. In P. fimbriata from Queensland, contests between males usually are very brief and do no damage. Contests between Portia females are usually long and violent, and the victor may evict a loser and then eat the loser's eggs – but victorious females of P. fimbriata from Queensland do not kill and eat the losing female. If a P. fimbriata male from Queensland displays to a female, she may run away or she may charge at him. If the pair reach agreement after this, they will mate if she is mature, and if she is sub-adult he will cohabit in her nest until she finishes moulting, and then they mate. Unlike in other Portia species, females of P. fimbriata do not eat their mates during courting, nor during or after mating.
Ecology
P. fimbriata is found in the rain forests of India, Nepal, Sri Lanka, Hong Kong, Taiwan, New Guinea, the Solomon Islands, Malaysia including Malacca, Indonesia, and in Australia's Northern Territory and Queensland.
It lives on foliage, tree trunks, boulders, and rock walls. Throughout its range, this is the most common species of the genus Portia. Queensland specimens of P. fimbriata live near running water and where there is moderate light, while Northern Territory specimens live in caves where the light varies from rather dark at the back to much brighter around the mouths. Other populations of Portia also live with higher light levels than in Queensland, and some members of these other populations are found in webs exposed to direct sunlight for part of the day.
In Queensland, P. fimbriata shares its environment with a common prey, the very abundant Jacksonoides queenslandicus, and with large populations of other non-Portia salticids and non-salticid web-building spiders.
It is often difficult to find P. fimbriata in the wild, as its shape and movements are well disguised. The Queensland variety is quite easy to raise, while the Northern Territory variety is quite troublesome to maintain.
Predators
Ants prey on P. fimbriata while P. fimbriata does not stalk ants, regarding them as poisonous or very unpleasant. P. fimbriata is also preyed upon by birds, frogs, and mantises.
Images for kids
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"Squared-off" cephalothorax and eye pattern of jumping spiders
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Female P. fimbriata in its web
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A female Lyssomanes viridis (not the species in Queensland)
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Male of P. fimbriata
