Brachypelma hamorii

🔤 Taxonomy

Brachypelma hamorii is the currently accepted scientific name. In the hobby, this species was long confused with or sold as Brachypelma smithi, so accurate identification is still important.

English common names used in the hobby:

• Mexican orange knee tarantula
• Mexican 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 hamorii is a terrestrial New World tarantula from Mexico and one of the best-known beginner-friendly display species in the hobby. It is admired for its dark body, warm orange markings on the knees, and generally calm presence.

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

Like other Brachypelma, it can flick urticating hairs when stressed and should not be handled routinely. Adult females are long-lived and heavy-bodied, while mature males remain slimmer and live much shorter lives after maturity.

☠️ Venom and safety

A bite from Brachypelma hamorii 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 hamorii is native to western Mexico, especially Colima, Jalisco and nearby Pacific-slope areas. In the wild it is associated with seasonal dry forest, thorn scrub and burrowed ground retreats.

In captivity, that background points to:

• 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 hamorii 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. Buying captive-bred animals from reputable sources and keeping proof-of-origin documents is strongly recommended.

🤌 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 hamorii should be housed alone. It is not a social tarantula.

Small juveniles do best in modest, secure rearing tubs at first; upgrade gradually instead of putting a tiny spider straight into an adult display enclosure.

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

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

This species is often forgiving, but it still does best with stable conditions and minimal unnecessary 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

Ambient room lighting is sufficient, with no need for UVB or basking lamps.

Bright lamps are unnecessary and should not be used to force basking behavior.

🌡 Heating and temperature

Brachypelma hamorii does well at normal warm room temperatures:

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

Short-term mild fluctuations are usually tolerated, but overheating is dangerous and should be avoided.

💧 Humidity and water

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

Most of the substrate should remain dry on the surface, while one area may remain slightly moister deeper down. Good ventilation matters as much as humidity.

🌿 Enclosure and decoration

The substrate should hold shape and allow shallow digging. Compacted coco fiber, unfertilized soil, or safe terrestrial mixes work well. Adults usually benefit from around 8-12 cm of substrate depth.

A stable cork bark hide, a shallow water dish, and sparse stable decor are ideal. Avoid excessive enclosure height, unstable rocks, and mesh surfaces where claws can catch.

🪳 Feeding

Brachypelma hamorii is insectivorous. Suitable prey includes:

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

As a rough guide, feed slings every 3-5 days, juveniles once or twice weekly, and adults every 7-14 days when body condition supports it.

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, excess dampness, poor ventilation, fall injuries, and molting trouble.

Warning signs include a shriveled abdomen, weakness, repeated wall climbing in poor conditions, obvious 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 hamorii is one of the classic beginner-friendly tarantulas for a reason: it is attractive, usually steady in temperament, and does well with simple consistent care. A low secure enclosure, deep substrate, fresh water, and patience are the key ingredients.

📚 Sources and further reading

• World Spider Catalog — Brachypelma hamorii: accepted name and distribution.
• GBIF — Brachypelma hamorii: 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: The Tarantula Collective — Brachypelma hamorii — layout guidance; the exact dimensions selected here are an editorial planning example.