Brachypelma smithi

🔤 Taxonomy

Brachypelma smithi is the currently accepted scientific name. In older hobby use, this species was often known as Brachypelma annitha, and it has also often been confused with Brachypelma hamorii, so exact identification still matters.

Older names associated with the species include:

• Brachypelma annitha

English common names used in the hobby:

• Mexican red knee tarantula
• Smith’s red knee tarantula

For purchases and breeding records, keep the current scientific name alongside any older seller label. Brachypelma smithi and Brachypelma hamorii are separate accepted species, not interchangeable names for every Mexican red-knee. The World Spider Catalog records historical misidentifications, so an old care sheet headed “smithi” may describe hamorii. Ask for the breeder’s identification history before pairing animals; similarity of knee colour alone does not establish that a pair belongs to the same species.

📌 Description

Brachypelma smithi is a terrestrial New World tarantula from Mexico and one of the most famous tarantulas in the hobby. It is known for its dark body and bright reddish-orange knee markings.

Adult size is usually about 6-7 cm body length and about 14-16 cm legspan, with females typically heavier than mature males.

The species is often considered calm to moderately defensive depending on the individual. Like other Brachypelma, it can flick urticating hairs when stressed and should not be handled routinely.

☠️ Venom and safety

A bite from Brachypelma smithi can cause puncture wounds, pain and swelling. Human bite reports are too uneven to predict an individual reaction or assign a precise venom potency to every species. Do not interpret a quiet animal or a “mild venom” label as permission to handle it.

Urticating hairs are a separate hazard: they can irritate skin and injure eyes. Avoid rubbing exposed skin or eyes; suspected eye exposure needs prompt medical assessment. Keep your face away from the enclosure and wear eye protection and gloves when removing molts or used substrate.

Use long tools and a catch cup, with a second containment tub for transfers in a closed room. Keep hands out of retreats and webbing, do not hand-feed, and do not chase an escaping spider. Keep transfers low to limit fall injuries to the animal.

After a bite, wash the wound with soap and water and contact a poison centre or medical service with the scientific name and time of exposure. Seek urgent care for severe or spreading pain, muscle cramps or persistent symptoms; call emergency services for breathing difficulty, throat swelling or collapse. Do not cut the wound or try to extract venom. Treatment focuses on wound assessment and symptom control under medical supervision.

🌍 Distribution

Brachypelma smithi is native to Mexico, especially Pacific-side dry habitats in Guerrero. In the wild it is associated with tropical dry forest, scrub, rocky ground and burrows.

The care setup should reflect those conditions with:

• a low terrestrial enclosure with more floor space than height
• enough substrate for digging or reshaping a retreat
• dry to moderately dry surface conditions with a water dish available
• strong ventilation and stable warm room temperatures
• fall prevention, because heavy terrestrial tarantulas are easily injured

🌡 Climate across the native range

Monthly climate normals from reviewed GBIF occurrence locations:

Weather data by Open-Meteo.com · CC BY 4.0 · Monthly normals calculated by Herpeton Academy from daily archive values.

Location references use GBIF.org occurrence data where available; original occurrence records retain their source dataset licenses.

⚖️ Legal status

Brachypelma smithi is listed in CITES Appendix II. In the EU wildlife trade system, Brachypelma tarantulas are treated under Annex B rules.

The species is not relevant to the Bern Convention because it is not native to Europe. In Mexico, Brachypelma species are associated with national protection measures, so wild collection and export are sensitive legal issues. Captive-bred animals from reputable sources are strongly preferred.

🤌 Husbandry

• Adult enclosure: 45 × 30 × 30 cm (length × width × height).

Height includes substrate. Keep the open drop above it short, with no hard landing surfaces; enlarge the footprint for an unusually large adult.

Brachypelma smithi should be housed alone. It is not a social tarantula.

Young spiders should be raised in secure, simple containers first, with larger housing introduced only when they can use the extra space safely.

A practical adult enclosure is roughly 45 × 30 × 30 cm or larger, with a low profile and plenty of floor space. Good husbandry includes:

• Deep substrate
• A secure hide
• Good cross-ventilation
• A shallow water dish
• No dangerous climbing decor

This species usually does best in stable, calm conditions without excessive disturbance.

Before opening the enclosure, locate the spider and prepare a clear catch cup with a rigid lid. Work close to the floor inside a larger empty container when rehousing, and keep other people and pets away. Guide the spider into the cup without gripping its legs or abdomen. If it retreats or starts kicking hairs, pause instead of pursuing it around the enclosure. Urticating hairs can remain in old substrate and shed skins, so use tools for removal, avoid raising dust, and keep your face away from the opening.

For a new arrival, record the seller’s identification, acquisition date, approximate size, and last known molt. Keep feeding and molt notes for that individual: the useful comparison is its own changing condition, not how quickly another tarantula grows. Maintain water and leave a newly occupied retreat intact; repeatedly lifting the hide to inspect a hidden spider prevents it from settling.

💡 Lighting

Keep lighting simple: ordinary room light and a consistent day-night cycle are enough.

Bright lamps are unnecessary and may make the tarantula more reclusive.

🌡 Heating and temperature

Brachypelma smithi does well at normal warm room temperatures:

• Daytime air: 20-26 °C
• Night: 18-21 °C

Overheating is a greater risk than mildly cool conditions. Temperatures near or above 30°C should be avoided.

💧 Humidity and water

This species does best in a dry-to-moderately humid enclosure with constant access to fresh water.

Keep most of the substrate dry on the surface while allowing one slightly moister area deeper down. Avoid stagnant damp air.

🌿 Enclosure and decoration

Use a substrate that holds shape and allows shallow digging, such as compacted coco fiber or unfertilized soil mixes. Adults usually benefit from around 8-12 cm of substrate depth.

Stable cork bark, a shallow water dish, and sparse stable decor are ideal. Avoid unstable rocks, mesh surfaces, and excess height that increases injury risk in a fall.

🪳 Feeding

Brachypelma smithi is insectivorous. Suitable prey includes:

• Crickets
• Roaches
• Locusts where available
• Mealworms or superworms only in moderation

Young spiders can be fed more often, while adults usually need a 7-14 day rhythm adjusted to abdomen size, recent molts, and prey size.

Choose prey by the spider’s body size, not its full leg span. For very small juveniles, a small freshly killed feeder placed near the retreat can be easier to manage than an active insect. Remove uneaten prey and accessible food remains within 24 hours; never leave a cricket loose with a spider that may be preparing to molt. A calendar is only a starting point for feeding. If the abdomen is already very full, reduce the next meal or extend the interval rather than trying to accelerate growth.

Food refusal can accompany a darkening abdomen, reduced activity, or a sealed retreat before a molt. Stop offering live prey in that situation and keep drinking water available. After the molt, wait until the fangs have darkened and hardened before resuming feeding; a fixed number of days is not reliable for every size and temperature. Do not uncover a sealed burrow just to offer a meal.

🥚 Breeding

Brachypelma are often bred in captivity, but pairing should still be planned rather than casual. Both animals should be mature, well fed but not obese, and correctly identified; keepers should avoid mixing uncertain localities or similar-looking species.

A mature male should be introduced to the female’s enclosure only under close supervision, usually after he has made a sperm web. The pair must have escape space and the keeper must be ready to separate them, because cannibalism and injury are possible.

If pairing succeeds, the female may produce an egg sac weeks or months later. Disturbance during this period can cause sac abandonment or eating. Spiderlings require many small ventilated rearing cups, tiny prey, accurate labels, and steady moisture management.

Because Brachypelma species are CITES Appendix II and are normally treated as EU Annex B animals, keep records of the parents, dates, offspring numbers, and transfers. Breed only when there is a lawful, realistic plan for the spiderlings.

🩺 Common problems

Common problems include dehydration, poor ventilation, excess dampness, falls, and molting complications.

Warning signs include a shriveled abdomen, weakness, repeated wall climbing in poor conditions, visible decline, and difficult molts. A tarantula on its back is often simply molting and should not be disturbed.

Visible fluid loss after a fall, a damaged abdomen, or persistent inability to stand requires prompt advice from a veterinarian experienced with invertebrates. Do not force-feed or attempt improvised treatment with oils, powders, or household adhesives.

📌 Conclusion

Brachypelma smithi is one of the classic Mexican display tarantulas and remains appealing to keepers who want a hardy terrestrial species with bold coloration. A low secure enclosure, deep substrate, fresh water, moderate warmth, and steady routine care will suit it well.

📚 Sources and further reading

• World Spider Catalog — Brachypelma smithi: accepted name and distribution.
• GBIF — Brachypelma smithi: species record.
• Tom’s Big Spiders — Brachypelma hamorii: comparative Brachypelma care, not species-specific measurements.
• University of Illinois College of Veterinary Medicine: general feeding, molt safety, and veterinary care.
• EU Regulation 2026/1383, Annex B, Brachypelma spp. (II), checked 2026-09-15; official BOE reproduction.
• CITES Appendices, checked 2026-05-04
• MedlinePlus: tarantula bites and hair exposure
• Kaderka et al. (2019): urticating setae in tarantulas
• Waggoner et al. (1997): eye injury from tarantula hairs
• Enclosure planning reference: Tom’s Big Spiders — Tarantula Enclosures from Lorex Plastics: A Review — layout guidance; the exact dimensions selected here are an editorial planning example.