Mexican redknee tarantula (Brachypelma smithi)

loading
Mexican redknee tarantula on sand
loading
Loading more images and videos...

Mexican redknee tarantula fact file

Mexican redknee tarantula description

KingdomAnimalia
PhylumArthropoda
ClassArachnida
OrderAraneae
FamilyTheraphosidae
GenusBrachypelma (1)

The venomous but docile Mexican redknee tarantula (Brachypelma smithi) is the most common spider used in movies due to its large size and beautiful colouration. A particularly striking tarantula, the Mexican redknee has a dark brown body and legs, with orange-red leg joints (3). The ends of the legs can detect vibrations, smells and tastes, to help the tarantula locate prey and the opposite sex, although it also has a group of eight eyes on the top of the carapace (4).

Synonyms
Euathlus smithi.
Top

Mexican redknee tarantula biology

In the wild, Mexican redknee tarantulas mate in the summer, shortly after the male’s maturing moult, usually in the rainy season (July and August) (7). Mating occurs in or near to the female’s burrow, where the male uses his pedipalps (front limbs) to transfer his sperm into openings in the underside of the female’s abdomen. After mating, some females will try to kill and eat the male, although this has never been observed in the wild (7). The sperm and eggs are stored in the female’s body and not laid until spring. In the spring, the female deposits hundreds of eggs and the sperm onto a silk mat which she has made and then fashions this mat into a ball or egg sac. Fertilisation takes place within minutes and the spiderlings hatch in just less than three months (7), but the spiderlings remain in the egg-sac for a further three weeks. Once out of the egg-sac they spend two weeks in the burrow before dispersing. Males mature at about four years of age and females two to three years later at about six or seven years old (3). They are a long-lived species with females living up to 25 to 30 years old (4); however males only live about one year after maturity (7).

Hunting at night by lying in ambush, the Mexican redknee tarantula attacks insects, small frogs, small lizards, and mice. An area on the end of each leg is sensitive to smells, tastes and vibrations, and this is used to detect prey. The tarantula holds its prey with its pedipalps (front limbs) and injects it with venom delivered via two hollow fangs. This venom has a double purpose, paralysing the prey as well as beginning digestion. Once the venom has acted, the tarantula is able to suck up the proteins and fats of its prey, leaving just a small ball of undigested body parts (4).

This usually docile tarantula will kick hairs off the abdomen with its hind legs when threatened, which cause blindness if they hit the eyes of a predator and can also cause a rash on the skin (4).

Top

Mexican redknee tarantula range

Mexican redknee tarantulas are found along the central Pacific coast of Mexico, from southern coastal Jalisco to north-western Oaxaca State and inland to the states of Mexico and Morelos (5).

Top

Mexican redknee tarantula habitat

The Mexican redknee tarantula lives in ground burrows (6), in rocky areas under thorny vegetation, usually in scrubland or desert, dry thorn forest or tropical deciduous forest (4) (5).

Top

Mexican redknee tarantula status

The Mexican redknee tarantula is classified as Near Threatened (NT) on the IUCN Red List (1), and is listed on Appendix II of CITES (2).

IUCN Red List species status – Near Threatened

Top

Mexican redknee tarantula threats

This particular species is the most popular captive tarantula species in the world, and prior to 1985 it was collected in thousands (6). Habitat loss is now the major threat to the Mexican redknee tarantula.

Top

Mexican redknee tarantula conservation

Listed on Appendix II of the Convention on International Trade in Endangered Species (CITES) in 1985, the Mexican redknee tarantula can now only be traded internationally according to quotas and with trade permits (6), and in Mexico permits are required to collect or remove any spider from the Theraphosid family (5).

View information on this species at the UNEP World Conservation Monitoring Centre.
Top

Find out more

For further information on the Mexican redknee tarantula: 

  • Locht, A., Yáñez, M. and Vázquez, I. (1999) Distribution and natural history of Mexican species of Brachypelma and Brachypelmides (Theraphosidae, Theraphosinae) with morphological evidence to support their synonymy. The Journal of Arachnology, 27(1): 196-200.
  • West, R.C. (2005) The Brachypelma of Mexico. Journal of the British Tarantula Society, 20(4): 108-119.
Top

Authentication

Authenticated (25/03/08) by Rick West.
http://www.birdspiders.com

Top

Glossary

Carapace
In Arachnida, the shield that covers the fused head and thorax (the part of the body located near the head) also known as ‘cephalothorax’.
Deciduous
A plant that sheds its leaves at the end of the growing season.
Pheromone
A chemical produced by an animal, which stimulates a behavioural or physiological response by another member of the same species.
Venomous
Species that produce and can inject poisonous venom under the skin (usually through a bite or sting), causing injury, illness, or death.
Top

References

  1. IUCN Red List (March, 2011)
    http://www.iucnredlist.org
  2. CITES (May, 2005)
    http://www.cites.org/
  3. Jacksonville Zoo (March, 2008)
    http://www.jaxzoo.org/animals/biofacts/RedkneedTarantula.asp
  4. The Big Zoo (March, 2008)
    http://www.thebigzoo.com/Animals/Mexican_Red_Kneed_Tarantula.asp
  5. West, R.C. (2005) The Brachypelma of Mexico. Journal of the British Tarantula Society, 20(4): 108 - 119.
  6. Baxter, R.N. (1993) Keeping and Breeding Tarantulas. Chudleigh Publishing, Ilford, Essex.
  7. West, R.C. (2008) Pers. comm.
X
Close

Image credit

Mexican redknee tarantula on sand  
Mexican redknee tarantula on sand

© Jim Tuten / Animals Animals

Animals Animals / Earth Scenes
17 Railroad Avenue
Chatham
NY
12037
United States of America
Tel: +01 (518) 3925500
Fax: +01 (518) 3925550
info@animalsanimals.com
http://www.animalsanimals.com

X
Close

Link to this photo

ARKive species - Mexican redknee tarantula (Brachypelma smithi) Embed this ARKive thumbnail link ("portlet") by copying and pasting the code below.

Terms of Use - The displayed portlet may be used as a link from your website to ARKive's online content for private, scientific, conservation or educational purposes only. It may NOT be used within Apps.

Read more about

X
Close

MyARKive

MyARKive offers the scrapbook feature to signed-up members, allowing you to organize your favourite ARKive images and videos and share them with friends.

Play the Team WILD game:

Team WILD, an elite squadron of science superheroes, needs your help! Your mission: protect and conserve the planet’s species and habitats from destruction.

Conservation in Action

Which species are on the road to recovery? Find out now »

Help us share the wonders of the natural world. Donate today!

Blog RSS