kids encyclopedia robot

Brazilian wandering spider facts for kids

Kids Encyclopedia Facts
Quick facts for kids
Brazilian wandering spider
Aranha armadeira(Phoneutria nigriventer) por Rodrigo Tetsuo Argenton (4).jpg
Phoneutria nigriventer
Scientific classification e
Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Chelicerata
Class: Arachnida
Order: Araneae
Infraorder: Araneomorphae
Family: Ctenidae
Genus: Phoneutria
Perty, 1833
Type species
Phoneutria fera
Perty, 1833
Species

See text

Diversity
9 species
Estação Ecológica de Santa Bárbara Giordano Rossi (12)
Brazilian wandering spider

Phoneutria is a genus of spiders in the family Ctenidae. They are mainly found in northern South America, with one species in Central America. Members of the genus are commonly referred to as Brazilian wandering spiders. Other English names include armed spiders (armadeiras in Brazilian Portuguese) and banana spiders (a name shared with several others).

Description

Phoneutria spiders can have a leg span of 13 to 18 cm (5 to 7 in). Their body length ranges from 17 to 48 mm (4364 to 1+5764 in).

The genus is distinguished from other related genera by the presence of a dense brush of fine hairs on the legs. Also, a dark linear stripe or stripes on the frontal (dorsal) palps and a single thin black line running along the back may help identify Phoneutria. Other features are the strong ventral marking on the underside of the legs with contrasting dark mid-segments and lighter joints, and the pattern on the underside of the abdomen with several rows of black dots, or an overall reddish colour.

Another indicator is a characteristic defensive posture with frontal legs held high. During the defensive display the body is lifted up into an erect position, the first two pairs of legs are lifted high (revealing the conspicuous black/light-banded pattern on the leg underside), while the spider sways from side to side with hind legs in a cocked position.

Taxonomy

258531 web Phoneutria tree
Rooted genetic evolutionary tree of the banana spiders genus Phoneutria and relatives. Some P. depilata specimen appear to be misinterpreted as P. boliviensis (blue color). Credit N. Hazzi (2021).

The genus Phoneutria was started by Maximilian Perty in 1833. The genus name is from the Greek φονεύτρια, meaning "murderess".

Species

Phoneutria nigriventer
Female of P. cf nigriventer: This and other species of the genus Phoneutria have medically significant venom that can be dangerous if the spiders are handled.

As of March 2021, the World Spider Catalog accepted the following species:

  • Phoneutria bahiensis Simó & Brescovit, 2001 – Brazil
  • Phoneutria boliviensis (F. O. Pickard-Cambridge, 1897) – Central, South America
  • Phoneutria depilata (Strand, 1909) – Guatemala, Honduras, Nicaragua, Costa Rica, Panama, Colombia, Ecuador
  • Phoneutria eickstedtae Martins & Bertani, 2007 – Brazil
  • Phoneutria fera Perty, 1833 (type) – Colombia, Ecuador, Peru, Brazil, Suriname, Guyana
  • Phoneutria keyserlingi (F. O. Pickard-Cambridge, 1897) – Brazil
  • Phoneutria nigriventer (Keyserling, 1891) – Brazil, Uruguay, Paraguay, Argentina
  • Phoneutria pertyi (F. O. Pickard-Cambridge, 1897) – Brazil
  • Phoneutria reidyi (F. O. Pickard-Cambridge, 1897) – Colombia, Venezuela, Peru, Brazil, Guyana

Behaviour

Wandering spiders are so-called because they wander the jungle floor at night, rather than residing in a lair or maintaining a web. During the day they hide inside termite mounds, under fallen logs and rocks, in banana plants (hence the "banana spider" nickname), and bromeliads. P. nigriventer is known to hide in dark and moist places in or near human dwellings.

P. nigriventer mates during the dry season from April to June, and is frequently observed during this time.

Distribution

Phoneutria are found in forests from Costa Rica southwards throughout South America east of the Andes including Colombia, Venezuela, the Guianas, Ecuador, Peru, Bolivia, Brazil, Paraguay, and into northern Argentina. Three species (P. reidyi, P. boliviensis and P. fera) are found in the Amazon region. One species (P. fera) is restricted to the Amazon, and one (P. boliviensis) ranges into Central America in Panama and Costa Rica. The remaining species are restricted to Atlantic Forest of Argentina, Paraguay and Brazil, including forest fragments in the Cerrado savanna. In Brazil, Phoneutria is only absent in the northeastern region north of Salvador, Bahia.

Phoneutria has been introduced to Chile and Uruguay.

Banana shipments

These spiders acquired their other common name, "banana spider", because it is claimed that they are occasionally found in shipments of bananas. Cases continue to be reported but without evidence of expert identification. In 2005, a man was bitten in Bridgwater, England by a spider in a shipment of bananas and, in 2014, a south London family photographed a spider that they claim was in a bunch of bananas delivered to their home.

Medical significance

Phoneutria spiders present a threat to humans. Their venom is toxic to people and their bites are sometimes deadly. These spiders' wandering nature is another reason they are considered so dangerous. In densely populated areas, Phoneutria species usually hide in houses, clothes, cars, boots, boxes and log piles, where they may bite if accidentally disturbed.

Spider mouthparts are adapted to envenomate very small prey; they are not well-adapted to attacking large mammals such as humans. Nevertheless, there are a few well-attested instances of death. In one case, a single spider killed two children in São Sebastião. The spider was positively identified as a Phoneutria.

These spiders seem to produce a smaller amount of venom during cold months (June to September) a minimum amount of 0.03 mg, an average of 0.44 mg and a maximum of 1.84 mg, during the summer months. The male produces less venom and is less lethal than the females, except for P. boliviensis, where the male is more toxic. The maximum amount among individuals was 3.10 mg (October 26), 4 mg (November 3), 5 mg (November 4) and 8 mg (October 31); 7 mg of dried venom is enough to kill 500 mice subcutaneously and 1,000 intravenously.

Symptoms reported after the bite are tachycardia, increased blood pressure, vertigo, fever, sweating, visual disturbances, nausea, vomiting, difficulty breathing and paralysis. They may appear within 10 to 20 minutes, and death within two to six hours. Death is usually caused by respiratory arrest.

Related pages

See also

Kids robot.svg In Spanish: Phoneutria para niños

kids search engine
Brazilian wandering spider Facts for Kids. Kiddle Encyclopedia.