Portia (genus)

Portia is a genus of jumping spider that feeds on other spiders (araneophagic). 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.

Distribution

The 17 described species are found in Africa, Australia, China, Malaysia, Myanmar, Nepal, India, Sri Lanka, the Philippines, and Vietnam.

Hunting techniques

Portia often hunt in ways that seem intelligent. Their favorite prey appears to be web-building spiders between 10% and 200% of their own size. Portia look like leaf detritus caught in a web, and this is often enough to fool web-building spiders, which have poor eyesight. When stalking web-building spiders, Portia try to make different patterns of vibrations in the web that aggressively mimic the struggle of a trapped insect or the courtship signals of a male spider, repeating any pattern that induces the intended prey to move towards the Portia.Portia fimbriata has been observed to perform vibratory behavior for three days until the victim decided to investigate. They time invasions of webs to coincide with light breezes that blur the vibrations that their approach causes in the target's web; and they back off if the intended victim responds belligerently. Other jumping spiders take detours, but Portia is unusual in its readiness to use long detours that break visual contact.

Portia

Portia may refer to:

Biology

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People with the given name

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Portia (moon)

Portia (/ˈpɔːrʃə/ POR-shə) is an inner satellite of Uranus. It was discovered from the images taken by Voyager 2 on 3 January 1986, and was given the temporary designation S/1986 U 1. The moon is named after Portia, the heroine of William Shakespeare's play The Merchant of Venice. It is also designated Uranus XII.

Portia is the second-largest inner satellite of Uranus after Puck. The Portian orbit, which lies inside Uranus' synchronous orbital radius, is slowly decaying due to tidal deceleration. The moon will one day either break up into a planetary ring or hit Uranus.

It heads a group of satellites called the Portia Group, which includes Bianca, Cressida, Desdemona, Juliet, Rosalind, Cupid, Belinda and Perdita. These satellites have similar orbits and photometric properties.

Little is known about Portia beyond its size of about 140 km, orbit, and geometric albedo of about 0.08.

In the Voyager 2 images, Portia appears as an elongated object whose major axis points towards Uranus. The ratio of axes of the Portia's prolate spheroid is 0.8 ± 0.1. Its surface is grey in color. Observations with Hubble Space Telescope and large terrestrial telescopes found water ice absorption features in the spectrum of Portia.

Porcia Catonis

Porcia Catonis (c.70 BC – June 43 BC (or October 42 BC)), (Porcia "of Cato", in full Porcia Catonis filia, "Porcia the daughter of Cato") also known simply as Porcia, occasionally spelled "Portia" especially in 18th-century English literature, was a Roman woman who lived in the 1st century BC. She was the daughter of Marcus Porcius Cato Uticencis and his first wife Atilia. She is best known for being the second wife of Marcus Junius Brutus, the most famous of Julius Caesar's assassins, and for her suicide, reputedly by swallowing hot coals.

Biography

Early life

Porcia was born between 73 BC and 64 BC. She had an affectionate nature, was addicted to philosophy and was full of an understanding courage.Plutarch describes her as being prime of youth and beauty. When she was still very young, her father divorced her mother for adultery.

At a young age she was married first to Marcus Calpurnius Bibulus, her father's political ally. This marriage occurred between 58 BC and 53 BC. With him she may have had a son, Lucius Calpurnius Bibulus, although modern historians believe Porcia was too young to have mothered Lucius, and that he was Bibulus' son by his previous marriage, as he was old enough to fight in the battle of Philippi in 42 BC. He died in 32 BC.