Acanthoscurria geniculata

🔤 Taxonomy

Acanthoscurria geniculata is the currently accepted scientific name. Older combinations associated with the species include:

• Mygale geniculata
• Scurria geniculata

English common names used in the hobby:

• Brazilian whiteknee tarantula
• Giant white knee tarantula

📌 Description

Acanthoscurria geniculata is a large terrestrial New World tarantula from Brazil, recognized by its dark body and bold white banding on the legs. It is one of the most popular large display tarantulas because it grows to an impressive size, feeds strongly, and is usually visible more often than many burrowing species.

Adult size is usually about 8-10 cm body length and about 18-20 cm legspan, with females typically heavier than mature males.

This is not a handling species. Like other New World tarantulas, it can flick urticating hairs when stressed, and large specimens can be very food-responsive.

The feeding response is the husbandry trait that most often surprises new keepers. Vibrations from opening the lid or moving a water dish can trigger a rapid turn or short rush. Use long tools, keep fingers away from the feeding zone, and assume that a visible spider may move before its intention is obvious.

🌍 Distribution

Acanthoscurria geniculata is native to Brazil, especially humid tropical northern and northeastern regions. In the wild it is associated with warm forest-edge and ground-level habitats with loose soil, leaf litter and retreats.

In captivity, that background points to:

• a low terrestrial enclosure with deep, shape-holding substrate
• a secure hide and room to retreat below the surface
• moderate humidity with good ventilation, not stale wet substrate
• fresh water always available
• fall prevention and calm maintenance

🌡 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

Acanthoscurria geniculata is not currently listed in the CITES Appendices. No specific current listing for this species is typically applied in Annexes A-D of the EU wildlife trade regulations.

The species is not relevant to the Bern Convention because it is not native to Europe. Local rules on import, sale, transport, exhibition, and breeding may still apply, so proof of legal origin is advisable.

🤌 Husbandry

Acanthoscurria geniculata should be housed alone. A practical adult enclosure is low and spacious, roughly 35 x 30 x 25 cm or larger, with more floor space than height.

Start slings in small, escape-proof containers where prey, molts, and hydration can be checked easily, then move them up in stages as they grow.

Stage management is especially important in large terrestrial species. Slings need smaller containers with reachable prey and slightly more stable moisture around part of the substrate. Juveniles can be moved up gradually as they gain size. Heavy adults need low, stable enclosures with deep substrate and no tall fall zone, because abdominal injuries from falls are a serious risk.

The essentials are:

• Deep substrate for shallow digging
• A secure hide
• Good ventilation
• A sturdy water dish
• No dangerous climbing structures

Before opening the enclosure, prepare a catch cup and clear the work area. Remove prey remains and clean the dish with long forceps instead of reaching across the spider. Full substrate replacement is rarely necessary; spot-cleaning preserves the retreat and reduces defensive encounters. Quarantine new specimens with separate tools and record meals, molts, and unexplained changes in behavior.

💡 Lighting

A regular room light cycle is enough. Avoid lamps that create a dry hot spot.

🌡 Heating and temperature

Aim for steady warm room temperatures:

• Daytime: around 24-28°C
• Night: slight drop acceptable

Overheating is dangerous. Temperatures at or above 30°C should be avoided.

💧 Humidity and water

Acanthoscurria geniculata does better with moderate humidity than many dry-habitat tarantulas. The substrate should not be waterlogged, but it should not stay bone dry for long periods either.

Fresh water should always be available, and one part of the enclosure can remain slightly more humid than the rest.

Pour water into one corner or lightly overflow the dish so the lower substrate retains moisture while the walking surface can dry. Constant spraying wets only the surface and can leave the enclosure alternately swampy and dry. Cross-ventilation should prevent persistent condensation and must not create openings that a small sling can squeeze through.

🌿 Enclosure and decoration

Use a substrate that holds shape and allows shallow digging, such as coco fiber, unfertilized soil, or mixed terrestrial substrates. Adults usually benefit from 10 cm or more of substrate depth.

A cork bark hide, water bowl, and stable simple decor are enough. Avoid excessive enclosure height because heavy tarantulas can be badly injured in falls.

🪳 Feeding

Acanthoscurria geniculata is insectivorous and usually feeds eagerly. Suitable prey includes:

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

Fast-growing juveniles can eat often, but adults usually do better on a measured 7-10 day rhythm adjusted to body condition.

Feeding changes with age. Slings can eat smaller prey or prekilled pieces more often, but uneaten prey should come out quickly, especially around premolt. Adults need less frequent meals, and an oversized abdomen is a reason to slow down, not feed more.

Strong appetite is not evidence that more food is required. Keep the abdomen proportionate to the carapace and reduce both prey size and frequency if it becomes markedly swollen. After a molt, wait for the fangs to turn fully black before offering prey; a large adult may need a week or more to harden safely.

🩺 Common problems

Common problems include dehydration, stagnant damp conditions, poor ventilation, unsafe enclosure height, and molting difficulties.

Warning signs include a shriveled abdomen, lethargy, repeated wall climbing, refusal to eat with visible decline, and difficult molts.

Hair exposure can cause intense skin or eye irritation. Do not rub the face during maintenance, and rinse exposed skin and clean tools afterward. A spider on its back is normally molting and must not be flipped. Fresh fall injuries, leaking hemolymph, severe dehydration, or a clearly failed molt require minimal handling and prompt advice from an experienced exotic veterinarian.

📌 Conclusion

Acanthoscurria geniculata is a large, attractive, and rewarding display tarantula for keepers who want a robust terrestrial species. A secure low enclosure, moderate humidity, fresh water, and steady warm conditions are the basis of reliable care.

📚 Sources and further reading

• CITES Checklist and Appendices - legal-status reference
• EU wildlife trade regulations - legal-status reference
• GBIF species entry for Acanthoscurria geniculata
• World Spider Catalog species entry
• Tarantula Collective: Acanthoscurria geniculata care
• Tom’s Big Spiders: Acanthoscurria husbandry notes