Portia (genus)
Encyclopedia
Portia is a genus
of jumping
spider
which feeds on other spiders (araneophagic). They are remarkable for their hunting behaviour which suggests they are capable of learning and problem solving, traits normally attributed to much larger animals.
are found in Africa
, Australia
, China
, Malaysia, Myanmar
, Nepal
, India
, Sri Lanka
, the Philippines
, and Vietnam
.
caught in a web, and this is often enough to fool web-building spiders, which have poor eyesight. When stalking web-building spiders, Portias 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 their approach causes in the target's web; and they back off if the intended victim responds belligerently. Portias that retreat may approach along an overhanging twig or rock, descend down a silk thread and kill the prey. Other jumping spiders take detours, but Portia is unusual in its readiness to use long detours that break visual contact.
Laboratory studies show that Portia learns very quickly how to overcome web-building spiders that neither it nor its evolutionary ancestors would have met in the wild. Portia’s accurate visual recognition of potential prey is an important part of its hunting tactics. For example in one part of the Philippines local Portia spiders attack from the rear against the very dangerous spitting spider
s, which themselves hunt jumping spiders. This appears to be an instinct
ive behavior, as laboratory-reared Portias of this species do this the first time they encounter a spitting spider. On the other hand they will use a head-on approach against spitting spiders that are carrying eggs. However, experiments that pitted Portias against "convincing" artificial spiders with arbitrary but consistent behavior patterns showed that Portia’s instinctive tactics are only starting points for a trial-and-error approach from which these spiders learn very quickly. Nonetheless, they seem to be relatively slow "thinkers", as they solve tactical problems by using brains vastly smaller than mammalian predators'. Against other jumping spiders, which also have excellent vision, Portias may mimic fragments of leaf litter detritus. When close to biting range, Portias use different combat tactics against different prey spiders. On the other hand they simply stalk and rush unarmed prey such as flies, and also capture prey by means of sticky webs.
The spider also practices cannibalism
before and after copulation. The female usually twists and lunges at the mounted male (P. fimbriata however, is an exception; it does not usually exhibit such behavior.). If the male is killed before completing copulation, the male sperm is removed and the male is then eaten. If the male finishes mating before being killed, the sperm is kept for fertilization and the male is eaten. A majority of males are killed during sexual encounters.
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of jumping
Jumping spider
The jumping spider family contains more than 500 described genera and about 5,000 described species, making it the largest family of spiders with about 13% of all species. Jumping spiders have some of the best vision among invertebrates and use it in courtship, hunting and navigation...
spider
Spider
Spiders are air-breathing arthropods that have eight legs, and chelicerae with fangs that inject venom. They are the largest order of arachnids and rank seventh in total species diversity among all other groups of organisms...
which feeds on other spiders (araneophagic). They are remarkable for their hunting behaviour which suggests they are capable of learning and problem solving, traits normally attributed to much larger animals.
Distribution
The 17 described speciesSpecies
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
are found in Africa
Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...
, Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
, China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
, Malaysia, Myanmar
Myanmar
Burma , officially the Republic of the Union of Myanmar , is a country in Southeast Asia. Burma is bordered by China on the northeast, Laos on the east, Thailand on the southeast, Bangladesh on the west, India on the northwest, the Bay of Bengal to the southwest, and the Andaman Sea on the south....
, Nepal
Nepal
Nepal , officially the Federal Democratic Republic of Nepal, is a landlocked sovereign state located in South Asia. It is located in the Himalayas and bordered to the north by the People's Republic of China, and to the south, east, and west by the Republic of India...
, India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
, Sri Lanka
Sri Lanka
Sri Lanka, officially the Democratic Socialist Republic of Sri Lanka is a country off the southern coast of the Indian subcontinent. Known until 1972 as Ceylon , Sri Lanka is an island surrounded by the Indian Ocean, the Gulf of Mannar and the Palk Strait, and lies in the vicinity of India and the...
, the Philippines
Philippines
The Philippines , officially known as the Republic of the Philippines , is a country in Southeast Asia in the western Pacific Ocean. To its north across the Luzon Strait lies Taiwan. West across the South China Sea sits Vietnam...
, and Vietnam
Vietnam
Vietnam – sometimes spelled Viet Nam , officially the Socialist Republic of Vietnam – is the easternmost country on the Indochina Peninsula in Southeast Asia. It is bordered by China to the north, Laos to the northwest, Cambodia to the southwest, and the South China Sea –...
.
Hunting techniques
Portias often hunt in ways that seem intelligent. Their favorite prey appears to be web-building spiders between 10% and 200% of the Portia’s size. Portias look rather like leaf detritusDetritus
Detritus is a biological term used to describe dead or waste organic material.Detritus may also refer to:* Detritus , a geological term used to describe the particles of rock produced by weathering...
caught in a web, and this is often enough to fool web-building spiders, which have poor eyesight. When stalking web-building spiders, Portias try to make different patterns of vibrations in the web that aggressively mimic
Aggressive mimicry
Aggressive mimicry is a form of mimicry where predators, parasites or parasitoids share similar signals with a harmless model, allowing them to avoid being correctly identified by their prey or host...
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 their approach causes in the target's web; and they back off if the intended victim responds belligerently. Portias that retreat may approach along an overhanging twig or rock, descend down a silk thread and kill the prey. Other jumping spiders take detours, but Portia is unusual in its readiness to use long detours that break visual contact.
Spitting spider
Spitting spiders are members of the family Scytodidae. There are several genera, of which Scytodes is the best-known. Over 150 species of scytodids have been described worldwide....
s, which themselves hunt jumping spiders. This appears to be an instinct
Instinct
Instinct or innate behavior is the inherent inclination of a living organism toward a particular behavior.The simplest example of an instinctive behavior is a fixed action pattern, in which a very short to medium length sequence of actions, without variation, are carried out in response to a...
ive behavior, as laboratory-reared Portias of this species do this the first time they encounter a spitting spider. On the other hand they will use a head-on approach against spitting spiders that are carrying eggs. However, experiments that pitted Portias against "convincing" artificial spiders with arbitrary but consistent behavior patterns showed that Portia’s instinctive tactics are only starting points for a trial-and-error approach from which these spiders learn very quickly. Nonetheless, they seem to be relatively slow "thinkers", as they solve tactical problems by using brains vastly smaller than mammalian predators'. Against other jumping spiders, which also have excellent vision, Portias may mimic fragments of leaf litter detritus. When close to biting range, Portias use different combat tactics against different prey spiders. On the other hand they simply stalk and rush unarmed prey such as flies, and also capture prey by means of sticky webs.
Reproduction
Portia exhibits a different mating behavior and strategy compared to other jumping spiders. In most jumping spiders, males mount females to mate. In Portia the female drops a dragline after the male mounts her, mating in mid-air. Before this happens the male shows off his legs and extends them stiffly and shakes them to attract the female. The female then drums on the web. Mating with Portia spiders can occur off or on the web.The spider also practices cannibalism
Cannibalism (zoology)
In zoology, cannibalism is the act of one individual of a species consuming all or part of another individual of the same species as food. Cannibalism is a common ecological interaction in the animal kingdom and has been recorded for more than 1500 species...
before and after copulation. The female usually twists and lunges at the mounted male (P. fimbriata however, is an exception; it does not usually exhibit such behavior.). If the male is killed before completing copulation, the male sperm is removed and the male is then eaten. If the male finishes mating before being killed, the sperm is kept for fertilization and the male is eaten. A majority of males are killed during sexual encounters.
Species
- Portia africanaPortia africanaPortia africana is a jumping spider found in Angola, Cameroon, the Central African Republic, Gabon, Ghana, the Ivory Coast, Sierra Leone, Zaire and Zambia. Its conspicuous main eyes provide vision more acute than a cat's during the day and 10 times more acute than a dragonfly's, and this is...
(SimonEugène SimonEugène Simon was a French arachnologist. His many taxonomic contributions include categorizing and naming many spiders, as well as creating genera such as Anelosimus, Psellocoptus and Phlogius....
, 1886) — WestWest AfricaWest Africa or Western Africa is the westernmost region of the African continent. Geopolitically, the UN definition of Western Africa includes the following 16 countries and an area of approximately 5 million square km:-Flags of West Africa:...
, Central AfricaCentral AfricaCentral Africa is a core region of the African continent which includes Burundi, the Central African Republic, Chad, the Democratic Republic of the Congo, and Rwanda.... - Portia albimana (Simon, 1900) — IndiaIndiaIndia , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
to VietnamVietnamVietnam – sometimes spelled Viet Nam , officially the Socialist Republic of Vietnam – is the easternmost country on the Indochina Peninsula in Southeast Asia. It is bordered by China to the north, Laos to the northwest, Cambodia to the southwest, and the South China Sea –... - Portia assamensis Wanless, 1978 — India to Malaysia
- Portia crassipalpis (Peckham & Peckham, 1907) — SingaporeSingaporeSingapore , officially the Republic of Singapore, is a Southeast Asian city-state off the southern tip of the Malay Peninsula, north of the equator. An island country made up of 63 islands, it is separated from Malaysia by the Straits of Johor to its north and from Indonesia's Riau Islands by the...
, BorneoBorneoBorneo is the third largest island in the world and is located north of Java Island, Indonesia, at the geographic centre of Maritime Southeast Asia.... - Portia fimbriataPortia fimbriataPortia fimbriata, sometimes called the fringed jumping spider, is a jumping spider found in Australia and Southeast Asia. Adult females have bodies 6.8 to 10.5 millimetres long, while those of adult males are 5.2 to 6.5 millimetres long...
(Doleschall, 1859) — NepalNepalNepal , officially the Federal Democratic Republic of Nepal, is a landlocked sovereign state located in South Asia. It is located in the Himalayas and bordered to the north by the People's Republic of China, and to the south, east, and west by the Republic of India...
, Sri LankaSri LankaSri Lanka, officially the Democratic Socialist Republic of Sri Lanka is a country off the southern coast of the Indian subcontinent. Known until 1972 as Ceylon , Sri Lanka is an island surrounded by the Indian Ocean, the Gulf of Mannar and the Palk Strait, and lies in the vicinity of India and the...
, TaiwanTaiwanTaiwan , also known, especially in the past, as Formosa , is the largest island of the same-named island group of East Asia in the western Pacific Ocean and located off the southeastern coast of mainland China. The island forms over 99% of the current territory of the Republic of China following...
to AustraliaAustraliaAustralia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area... - Portia heteroidea Xie & Yin, 1991 — ChinaChinaChinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
- Portia hoggi Zabka, 1985 — Vietnam
- Portia jianfeng Song & Zhu, 1998 — China
- Portia labiataPortia labiataPortia labiata is a jumping spider found in Sri Lanka, India, Burma , Malaysia, Singapore, Java, Sumatra and the Philippines. In this medium-sized jumping spider, the front part is orange-brown and the back part is brownish...
(Thorell, 1887) — Sri Lanka to PhilippinesPhilippinesThe Philippines , officially known as the Republic of the Philippines , is a country in Southeast Asia in the western Pacific Ocean. To its north across the Luzon Strait lies Taiwan. West across the South China Sea sits Vietnam... - Portia orientalis Murphy & Murphy, 1983 — Hong KongHong KongHong Kong is one of two Special Administrative Regions of the People's Republic of China , the other being Macau. A city-state situated on China's south coast and enclosed by the Pearl River Delta and South China Sea, it is renowned for its expansive skyline and deep natural harbour...
- Portia quei Zabka, 1985 — China, Vietnam
- Portia schultziPortia schultziPortia schultzi is a jumping spider which ranges from South Africa in the south to Kenya in the north, and also is found in West Africa and Madagascar. In this species, which is slightly smaller than some other species of the genus Portia, the bodies of females are 5 to 7 millimetres long, while...
Karsch, 1878 — Central, EastEast AfricaEast Africa or Eastern Africa is the easterly region of the African continent, variably defined by geography or geopolitics. In the UN scheme of geographic regions, 19 territories constitute Eastern Africa:...
, Southern AfricaSouthern AfricaSouthern Africa is the southernmost region of the African continent, variably defined by geography or geopolitics. Within the region are numerous territories, including the Republic of South Africa ; nowadays, the simpler term South Africa is generally reserved for the country in English.-UN...
, MadagascarMadagascarThe Republic of Madagascar is an island country located in the Indian Ocean off the southeastern coast of Africa... - Portia songi Tang & Yang, 1997 — China
- Portia strandi Caporiacco, 1941 — EthiopiaEthiopiaEthiopia , officially known as the Federal Democratic Republic of Ethiopia, is a country located in the Horn of Africa. It is the second-most populous nation in Africa, with over 82 million inhabitants, and the tenth-largest by area, occupying 1,100,000 km2...
- Portia taiwanica Zhang & Li, 2005 — Taiwan
- Portia wui Peng & Li, 2002 — China
- Portia zhaoi Peng, Li & Chen, 2003 — China
External links
- Description in the Diagnostic Drawing Library
- Guide to Common Singapore Spiders: P. labiata
- Photographs of P. labiata
- Photographs of P. fimbriata
- Photographs of P. schultzi
- Photographs of P. africana
- Photographs of P. quei
- Frontal view of P. fimbriata
- Information about P. fimbriata (with distribution in Australia)
- Prey capture and mating behavior in jumping spiders belonging to the genus Portia