Number 16

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Gaius villosus

Number 16 or number 16 was an Australian spider of the species Gaius villosus , which hatched around the turn of the year 1973/1974 and was observed since June 22, 1975 by the arachnologist Barbara York Main as part of a long-term ecological study. On October 31, 2016, it was discovered that Number 16 had apparently been killed by a parasitic wasp . Number 16 was the longest recorded lifespan spider at at least 43 years of age. It replaced a tarantula , for which an age of 28 years is proven.

The study

Starting in March 1974, the Australian arachnologist Barbara York Main marked residential tunnels of the long-lived species Gaius villosus in the North Bungulla Nature Reserve ( 31 ° 32 ′ 0 ″  S , 117 ° 35 ′ 0 ″  E ) . The 104 hectare nature reserve is located in the Shire of Tammin in the wheat belt of the state of Western Australia . Main grew up on a farm in the immediate vicinity.

The aim of the study was to obtain , for the first time through a long-term study over two decades, insights into the life cycle , reproductive behavior, demographic distribution and the ability of trapdoor spiders to spread into new habitats.

origin

An analysis of the spatial distribution and age of the spiders examined in the mid-1970s showed that Number 16 is most likely the descendant of a spider that was included in the study as Number 1 . Number 1 was observed as a large and fully grown spider as early as 1968 and 1969, at the time it must have been six or more years old. She was at least twelve years old when the study started.

Number 16 left her mother's apartment tube in the fall of 1974. So she hatched in the previous year and spent the following months with her siblings in the sealed tube. It was found for the first time on June 22, 1975 by researchers who marked their living tube on that day and were able to deduce the age of Number 16 from its measurements .

death

On October 31, 2016, the empty tube of Number 16 was found with disordered branches instead of an orderly fan around the entrance opening. The trap door was in its normal position but had a perforation in the middle. Apparently, Number 16 had been killed by a wasp (Pompilidae) within the six months since the last inspection when she was alive in her apartment . Wasps stun their prey and lay one or more eggs on it. After hatching, the larvae of the wasp feed on the still living host , causing the host to die.

longevity

With a documented age of 43 years, Number 16 has reached the longest scientifically proven spider life span . With this "age record" she replaced a tarantula from an animal keeping in the terrarium , for which the Guinness Book of Records stated an age of 28 years.

In nature, spiders of the Tasmanian species Hickmania troglodytes, which live mainly in the entrance areas of caves, probably reach an age of several decades.

Barbara York Main's study was initially planned to last about 20 years. The unexpected longevity of Number 16 was the reason for York to keep extending the study. Finally, in 2015, for reasons of age - when she was around 85 years old - she handed the study over to Leanda Mason, a doctoral student at Curtin University in Perth .

Media coverage

On April 19, 2018, the Australian arachnologists Leanda Denise Mason, Grant Wardell-Johnson and Barbara York Main published an article entitled The longest-lived spider: mygalomorphs dig deep, and persevere (German: The longest-lived spider: tarantulas dig deep and survive ) in the journal Pacific Conservation Biology . In the article, they announced the death of Number 16 and the circumstances in which it was found. They also provided a summary of the long-term study that had been carried out with it and briefly outlined the importance of this study and the longevity of trapdoor spiders for wildlife conservation in Western Australia.

The main content of the article became the basis for reports from various news agencies, including Agence France-Presse and the Deutsche Presse-Agentur , which in turn were picked up by numerous mass media at the end of April 2018. In doing so, errors in content were transported. So were Number 16 and the previous "record holder" often referred to as tarantulas referred. This is the English name for tarantulas , which are not closely related to the tarantulas. In addition, in headings such as the oldest spider in the world dies of a wasp sting, the death of Number 16 was greatly abbreviated, the fact that it was about the parasitization by a wasp was lost. Other media described Number 16 as a "poisonous spider" or claimed that Gaius villosus only leaves its living tube a few meters. In fact, females of the species never leave their living tubes for more than a few centimeters. With regard to the cause of the longevity, a greatly simplified representation was provided with the indication of sedentariness and the low energy consumption.

The international media also relied mainly on agency reports. A report appeared in the Internet edition of the Daily Telegraph , highlighting the poisonous nature of the spider and pointing out that there was no real danger of an encounter in the garden or at home. In addition, it was stated that Leanda Mason and her colleagues had the hope that Number 16 would reach the age of 50. In the English-language media, the reporting went well beyond the reproduction of the agency reports in some cases. The Washington Post reported in detail on the life story of Number 16 , the long-term study and Barbara York Main .

Individual evidence

  1. ↑ a b c Barbara York Main: Biology of the arid-adapted Australian trapdoor spider Anidiops villosus (Rainbow) . In: Bulletin of the British Arachnological Society 1978, Volume 4, No. 4, pp. 161-175, here pp. 162-163, online PDFhttp: //vorlage_digitalisat.test/1%3Dhttp%3A%2F%2Fbritishspiders.org.uk%2Fbulletin%2F040403.pdf~GB%3D~IA%3D~MDZ%3D%0A~SZ%3D~doppelsided%3D~ LT% 3DOnline% 20PDF ~ PUR% 3D , 1.6 MB.
  2. ↑ a b Barbara York Main: Biology of the arid-adapted Australian trapdoor spider Anidiops villosus (Rainbow) , pp. 164-166.
  3. ↑ a b c Leanda Denise Mason, Grant Wardell-Johnson and Barbara York Main: The longest-lived spider: mygalomorphs dig deep, and persevere . In: Pacific Conservation Biology , April 19, 2018, doi : 10.1071 / PC18015 .
  4. ↑ Stefano Mammola et al .: Record breaking achievements by spiders and the scientists who study them . In: PeerJ 2017, Volume 5, Article e3972, doi : 10.7717 / PEERJ.3972 .
  5. ↑ a b Avi Selk: The extraordinary life and death of the world's oldest known spider , The Washington Post , May 1, 2018, accessed May 18, 2018.
  6. ↑ a b Anonymus: Oldest spider in the world dies of wasp sting , FAZ.net , April 30, 2018, accessed on May 18, 2018.
  7. ↑ Kathrin Klette: Oldest spider in the world dies of a wasp sting , NZZ Online , April 30, 2018, accessed on May 18, 2018.
  8. ↑ Wasp stings the world's oldest spider to death , Stuttgarter Nachrichten , April 30, 2018, accessed on May 18, 2018.
  9. ↑ World's oldest spider dies at the age of 43 - researchers have an explanation for old age . Focus Online , April 28, 2018, accessed May 18, 2018.
  10. ↑ World's oldest spider has died , Spiegel Online , April 30, 2018, accessed May 18, 2018.
  11. ↑ World's oldest known spider dies at 43 after a quiet life underground , The Guardian , April 30, 2018, accessed May 18, 2018.
  12. ↑ Eli Meixler: The World's Oldest Known Spider Has Died at the Age of 43 From a Wasp Sting , Time , April 30, 2018, accessed May 18, 2018.
  13. ^ Henry Bodkin: Farewell, No. 16: scientists left 'miserable' after world's oldest spider dies aged 43 . The Telegraph , April 27, 2018, accessed May 18, 2018.