Date of this Version
Hardin, T., Sincage, J. AZA Mexican red kneed tarantula (Brachypelma smithi) Species Survival Plan (2015). Mexican red kneed Tarantula Care Manual. Silver Spring, MD: Association of Zoos and Aquariums.
Caring for any animal is more of an art than a science. What works for one keeper may not necessarily work for another. This may be based on unnoticed nuances, local climate or weather patterns, the personalities of the individual animals, or other minute details. This is a basic husbandry and breeding guide to the Mexican red knee tarantula (Brachypelma smithi). Any more specifics will have to be discovered personally or discussed with colleagues. Where many vertebrates have been kept in captivity for centuries a lot of invertebrates are relatively new to the husbandry world. Even though humans have kept and captive bred many tarantulas for decades; keepers and hobbyists around the world are still discovering new husbandry techniques and new species to keep every year.
The Mexican red knee tarantula (Brachypelma smithi (F. O. Pickard-Cambridge, 1897)) is a species of robust spider. The genus is found only in Southern North America and Central America; primarily Mexico to Panama (Valerrio 1980; Smith 1994). Brachypelma smithi is found along the Western faces of the Sierra Madre del Sur and Sierra Madre Occidental mountain ranges in Mexico. This terrestrial species rarely leaves the comfort of its burrow in the wild. Their burrows can be found near rocks or at the base of vegetation (Lockt, 1999). Mature males will participate in an annual migration to find willing partners but females and immature specimen stay relatively stationary.
Like all arachnids, Brachypelma are characterized by two body segments and eight legs. Their fangs are oriented vertically, grouping them into the Suborder Mygalomorphae. The Mexican red kneed tarantula sports a black abdomen covered by brown/ red hairs. The cephalothorax is also black with a khaki colored ring. The Brachypelma smithi is renowned for the bright orange to red-orange splashes of color on their patella; they may also sport smaller patches of color on the legs below the patella (Gurley, 1993).
New World tarantulas are notorious for their ability to discharge urticating hairs. When the spider feels threatened it may scrape the back of its abdomen and flick a cloud of microscopic needles that is capable of causing pain and discomfort to those that are easily irritated. Brachypelma are generally mild mannered and do not always respond to disturbances by flicking hairs or displaying a threat posture. The venom is an insect specific neurotoxin (Zhong, Y., Song, B., Lu, Q., et al., 2014). However, it can cause pain and discomfort similar to a bee sting.
The tarantulas of the genus Brachypelma are long-lived. The males reach maturity in 3-7 years, living only one year or less after the last molt. The females however, reach maturity in 4-10 years, and then are capable of living another decade or two (Locht, 1999).
The Brachypelma species from the west coast of Mexico are particularly docile and colorful. These traits have led to their being collected in large numbers for the pet trade. The destruction of the natural habitat and the high mortality before sexual maturity (99%) (Baerg, 1958) are two factors that affect the populations of these species, and combined with the illegal trade that normally involves the capture of pre-adult and adult tarantulas, can cause the extinction of these tarantulas. To regulate this trade and prevent their endangerment, all the species of this genus have been listed in appendix II of CITES (Locht, Yanez and Vazquez 1999). The IUCN lists the Red Knee tarantula as a Near Threatened species.
Mexican red kneed tarantulas are widely used as educational ambassadors within many AZA facilities. Although being a long lived species, precautions were needed in order to keep this species in collections. Captive reproduction for this genus is common in the private tarantula hobby. However, this species is rarely bred in AZA institutions. In 2007 the Mexican red kneed tarantula became an AZA managed program within the Terrestrial Invertebrate Taxon Advisory Group.