Phoneutria

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Phoneutria
Phoneutria nigriventer

Phoneutria nigriventer

Systematics
Order : Spiders (Araneae)
Subordination : Real spiders (Araneomorphae)
Partial order : Entelegynae
Superfamily : Lycosoidea
Family : Comb spiders (Ctenidae)
Genre : Phoneutria
Scientific name
Phoneutria
Perty , 1833

Phoneutria is a genus comprisingeight species in the family of comb spiders (Ctenidae). The species of the genus, to which the Brazilian wandering spider ( Phoneutria nigriventer ) belongs, are also often referred to as banana spiders in German. In their main area of ​​distribution in Brazil, they are called Armadeira (from Portuguese aranhas armadeiras "armed spiders"). All species are considered to be particularly aggressive and highly toxic .

description

The genus Phoneutria ( Greek  φονεύτρια "murderess") includes eight scientifically described species. The females reach a wingspan of 10 to 13 cm. The body of the female becomes 30 to 50 mm long, males are smaller, with a body length of up to 40 mm. The middle eyes of the front and back rows form a square. In contrast to the genus Ctenus , the outer eyes lie on a common elevation and are close together. The eyes in the back row are larger than those in the front row.

behavior

The name wandering spider comes from the fact that this genus does not lie in wait for prey like many other spiders, but actively hunts at night. During the day she hides in dark, damp places, often in human dwellings. If she feels disturbed, she exhibits a special threatening behavior in which she straightens the front part of the body and stretches the two front pairs of legs upwards. Since in this position she looks a bit as if she was holding pistols in the air, this explains the name "armed spider", which is common in Brazil. In this position, the spider sways in a characteristic way jerkily from side to side. Phoneutria are considered very aggressive and often bite without warning, but do not always administer poison to the bite wound. Some Phoneutria species have a reputation for attacking while jumping.

The mating season is from April to June, which is why P. nigriventer is particularly often seen during this time. The males build sperm nets with which they fill their mating flasks. When mating, they ride on the motionless female and transfer the sperm packages to her sperm library . After a few days the male can mate other females. The females weave an egg ball, which is glued to a smooth surface and guarded. After hatching, the young gather on the back of the mother, where they build a layer of tissue every day and feed themselves cannibalistically . After the first molt, they become independent. The females then produce more egg balls until their egg supply is exhausted. A total of three to four egg balls with up to 2500 young animals are produced.

Prey animals are cockroaches and other insects as well as small reptiles and amphibians .

distribution

Phoneutria species are found throughout South America from Ecuador to northern Argentina . The main distribution area is Brazil .

Occasionally, individual animals in banana boxes on cargo ships unintentionally end up in Europe, especially in supermarkets .

species

The genus includes eight species. (As of November 2017)

Poison

Phoneutria species are - along with some species of the real widows and the Sydney funnel -web spider - one of the few spiders in the world whose bite can pose a life-threatening danger to a healthy adult. They are believed to be responsible for most of the world's fatal spider poisoning accidents, although some sources cite the black widow here. This could be due to the fact that the wandering spider does not always inject venom into the bite wound and the number of fatal accidents has fallen to a few individual cases per year thanks to the wide availability of an antidote. In their book, Bücherl and Buckley describe a fatal incident in São Sebastião / State of São Paulo in which a spider killed two children. So far, ten deaths have been attributed to Phoneutria bites in Brazil . In the period from 1984 to 1996, a total of 422 bites had occurred, with the spiders being caught and identified as Phoneutria species. Bite accidents increased particularly in the area around Campinas . The investigations showed that the accidents increased in the months of March / April. The number of bite accidents is lowest in September / October. Most accidents occurred in the household during the day.

An intravenously administered amount of poison of only 6  µg is sufficient to kill a 20 g mouse (for comparison: the poison of the black widow ( Latrodectus mactans ) is only fatal to a mouse above 110 µg). Since the toxicological sensitivity of humans, measured by body weight, is four to five times higher than that of the mouse, Phoneutria is considered the most poisonous species in the world. In the Guinness Book of Records (published in 2007) it is therefore listed as the most poisonous spider.

In addition to severe pain, the spider's venom can also cause priapism (painful erection) in humans. It can last for many hours and, if left untreated, causes impotence. The toxin Tx2-6 of the species P. nigriventer has meanwhile been isolated.

Neurotoxin Phα1β as a pain reliever

The neurotoxin Phα1β obtained from the poison of the species Phoneutria nigriventer acted in animal experiments as a calcium channel blocker and pain reliever . The neurotoxin could relieve postoperative pain or be used as a potential drug in fibromyalgia . Unlike diclofenac, Phα1β does not affect the serum levels of neurotransmitters such as serotonin, noradrenaline and dopamine.

Web links

Commons : Phoneutria  - collection of pictures, videos and audio files

Phoneutria in the World Spider Catalog

literature

Individual evidence

  1. ↑ a b c toxinfo.med.tum.de , Toxinfo database of the MRI - search term “PHONEUTRIA” . (Last checked on September 6, 2009)
  2. ↑ a b c Martins & Bertani 2007
  3. ↑ Peters: Report on the achievements of the natural history of the arachnids during the years 1847 and 1848 . In: University of Michigan (Ed.): Archives for Natural History . tape 15 . Nicolai, 1849, p. 335 .
  4. ^ Ernst Josef Fittkau : Biogeography and Ecology in South America . tape 2 . Springer, Heidelberg 1969, ISBN 978-90-6193-071-6 , pp. 782 .
  5. ↑ Günter Schmidt: About the importance of the arachnids brought in with shiploads in Germany . In: Journal of Pest Science , Springer, Berlin / Heidelberg, Volume 26, Number 7 / July 1953, pp. 97-105
  6. ↑ Deadly spiders shopping for bananas . Spiegel Online , November 4, 2013
  7. ↑ Shopping in London: Killer Spider in the Fruit Crate , October 20, 2014
  8. ↑ Harpstedt: Supermarket evacuated because of poison spider - SPIEGEL ONLINE . Retrieved May 21, 2016.
  9. ↑ Bayreuth: Ten centimeter tall poisonous spider discovered in a supermarket , article on WELT.DE from February 12, 2017.
  10. ↑ Esslingen: Highly poisonous spider found in a supermarket , article on stuttgarter-zeitung.de from May 3, 2018.
  11. ↑ Natural History Museum of the Burgergemeinde Bern: World Spider Catalog Version 18.5 - Phoneutria . Retrieved November 15, 2017.
  12. ↑ Marcelo A. Dias, Miguel Simó, Ismael Castellano and Antonio D. Brescovit: Modeling distribution of Phoneutria bahiensis (Araneae: Ctenidae): an endemic and threatened spider from Brazil . In: Zoologia (Curitiba, Impr.), Vol. 28 No. 4 Curitiba Aug 2011
  13. ↑ Sobre la Presencia de Phoneutria boliviensis (F.OP Cambridge) (Araneae, Ctenidae) in Costa Rica (PDF; 123 kB) - About the occurrence of Phoneutria boliviensis in Costa Rica. In: The Journal of Arachnology , 11, p. 101 (Spanish)
  14. ↑ BJF Silva, WL Overal: Ocorrência de Phoneutria fera (Araneae: Ctenidae) no Estado do Pará, Brasil . In: Boletim do Museu Paraense Emílio Goeldi, série Zoologia , 15 (2), 1999, pp. 135-141.
  15. ↑ "Deadly" Banana Spider ... Or Not
  16. ↑ Animal Corner ( Memento of the original from August 22, 2009 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. Retrieved September 6, 2009. @1@ 2Template: Webachiv / IABot / www.animalcorner.co.uk
  17. ↑ a b Wolfgang Bücherl, Eleanor Buckley: Venomous Animals and their Venoms , vol. III.
  18. ↑ recorded by UNICAMP, the University Hospital Campinas
  19. ↑ Fábio Bucaretchi, Cláudia Regina de Deus Reinaldo, Stephen Hyslop, Paulo Roberto Madureira, Eduardo Mello de Capitani, Ronan José Vieira: A Clinico-Epidemiological Study of Bites by Spiders of the Genus Phoneutria . Rev. Inst. Med. Trop. S. Paulo, Vol. 42 N. 1 São Paulo, Feb. 2000
  20. ↑ KR Leite, E. Andrade, AT Ramos, FC Magnoli, M. Srougi and LR Troncone: Phoneutria nigriventer spider toxin Tx2-6 causes priapism and death: a histopathological investigation in mice . In: Toxicon , 2012 Oct., 60 (5), pp. 797-801, PMID 22750220
  21. ↑ Castro-Junior, Milano, Souza et al .: Phα1β toxin prevents capsaicin-induced nociceptive behavior and mechanical hypersensitivity without acting on TRPV1 channels . In: Neuropharmacology , 2013 Aug, 71, pp. 237-246, PMID 23597507 .
  22. ↑ a b de Souza, Drewes, Lima et al .: Antiallodynic effect and side effects of Phα1β, a neurotoxin from the spider Phoneutria nigriventer: comparison with ω-conotoxin MVIIA and morphine . In: Toxicon , December 1, 2011, 58 (8), pp. 626-633, PMID 21967810
  23. ↑ Hassanein, Hasan, Hamed et al .: Effects of diclofenac, piroxicam and alpha-tocopherol on monoaminelymphopoietic interfacing in mice . In: Arzneimittelforschung , 2004, 54 (12), pp. 847-856, PMID 15646369 .
  24. ↑ de Souza, da Costa Lopez, Castro et al .: The effects of Phα1β, a spider toxin, calcium channel blocker, in a mouse fibromyalgia model . In: Toxicon , 2014 Apr, 81, pp. 37-42, PMID 24491352