Mexican Redknee Tarantula

About the species

The Mexican redknee tarantula is one of the most recognisable tarantulas in the world: a stocky black body, a tan-to-orange "cap" on the front of the carapace, and eight legs banded with broad orange-red rings right at the knee joints. It comes from dry, deciduous forest on Mexico's Pacific slope, where it spends the day resting in a shallow burrow under a rock or among roots and ambushes passing insects near the entrance at night.

Which species is it, exactly?

For decades, both the trade and the literature listed this spider as Brachypelma smithi. In 2017, a taxonomic revision by Mendoza and Francke, backed by DNA barcoding, showed that animals from the Mexican states of Colima, Jalisco and Michoacán — the large majority of what's actually in the hobby — belong to a separate species, Brachypelma hamorii, first described back in 1997. True Brachypelma smithi remains restricted to a narrower range in the state of Guerrero and is considerably rarer in the trade. The two species look similar enough that they cannot be told apart from a photo alone; the reliable differences are in genitalia and DNA.

Size

For tarantulas, leg span — not body length — is the number that actually describes how "big" the animal is: an adult reaches roughly 13–16 cm across the legs, while the body itself is only about 5–6 cm long. Females tend to be somewhat stockier than the more slender males, and individual variation is considerable.

Is it dangerous? Venom and urticating hairs

For a healthy adult with no allergies, a bite is comparable in severity to a bee sting — painful but not medically significant — and this calm species rarely bites in the first place. The real everyday hazard is urticating hairs, which the spider kicks off its abdomen with its hind legs when it feels threatened. These tiny barbed hairs cause itching and a rash on skin, and if they contact the eyes or airways they can irritate sensitive membranes considerably more than the bite itself. Some caution — and ideally eye protection — is worthwhile when cleaning the enclosure.

Handling is not recommended

Despite its reputation as a calm, "beginner" species, handling is not recommended. Tarantulas have no internal skeleton, only a fragile exoskeleton, and a fall from as little as a few dozen centimetres can rupture the abdomen and is often fatal. The risk isn't worth a brief moment on someone's palm — the animal is much better appreciated through the terrarium glass.

Females live for decades, males for a few years

The difference in lifespan between the sexes is dramatic in this species: with good care, females live 25 to 30 years, while males, after their final adult moult, typically live only another 5 to 10 years. Anyone looking for a long-term companion should choose a female — though sex often can't be reliably determined in a young juvenile.

Terrarium, temperature and humidity

As a largely ground-dwelling, burrowing species, the terrarium should not be tall — a low, wide enclosure works better, with a footprint of at least roughly 30 × 30 cm for an adult and 10–15 cm of substrate depth for burrowing. A room temperature of about 22–27 °C is sufficient, with no need for the strong basking "sun" used for reptiles; a slightly warmer corner (up to about 28 °C) is helpful but not essential. Humidity should be moderate, around 60–70%, with a shallow water dish always available and good ventilation so the substrate doesn't turn waterlogged when misted. UVB lighting is not needed for this species, since spiders don't process vitamin D the way reptiles do.

Diet

It feeds on insects — crickets, roaches (such as Argentine wood roaches) or similar prey, ideally gut-loaded beforehand so the tarantula indirectly gets more nutrients. An adult eats one larger prey item roughly every 1–3 weeks; juveniles more often. Allow a few days to a week after a moult before offering food again.

Legal status: CITES Appendix II

The entire genus Brachypelma is protected under CITES: B. smithi (not yet distinguished from B. hamorii at the time) was listed in 1985, and the rest of the genus followed in 1994. An Appendix II listing does not ban trade — it regulates it: international trade is legal but requires proper permits and documentation of an animal's origin, which also gives a buyer some assurance the animal wasn't illegally taken from the wild.

Who it suits

Among tarantula keepers, this species is considered one of the most recommended for beginners, thanks to its calm temperament, slow growth and undemanding care with no complex temperature gradients. That doesn't mean it suits a completely inexperienced owner or works as a child's "touch" pet, though: it's a venomous, CITES-regulated exotic animal with specific dietary and housing needs that are worth researching thoroughly before buying.

Pros & cons