Brazilian Whiteknee Tarantula
Acanthoscurria geniculata
1. Deep Soil & Low-Ceiling Safety Setup
2. Two Great Ways to Set Up Your Habitat
Sizing the Tank: Slings vs. Adults
Putting a fingernail-sized baby ('sling') in a giant 10-gallon tank makes it impossible for them to find dinner:
Option A: Spiderlings ('Slings' Under 1.5")
Keep in a vented sling vial or micro acrylic cube (about 3–4× their legspan wide) with 2" of soil, a piece of moss, and a clean tattoo-ink cap or bottlecap for water.
Option B: Juveniles & Adults (2" to 7"+)
A 5- to 10-gallon glass or acrylic enclosure filled halfway up with 4–6" of packed reptile/invertebrate soil and a curved cork bark starter cave.
Ground Burrowers vs. Tree Climbers
Make sure your setup matches where your spider actually lives in nature:
Option A: Ground / Burrowing (Curly Hair, Red Knee, Arizona Blonde)
Wide floor space, deep 4–6" soil for bulldozing, and low ceiling clearance so a clumsy climber can never take a big fall.
Option B: Tree-Dwelling (Pinktoes, Versicolor, Jumping Spiders)
Tall enclosure with lots of side-wall air holes (cross-ventilation!) and tall cork bark reaching near the ceiling.
To Handle or Not to Handle?
Real talk from our invert team: tarantulas don't get cuddly from being held—handling is mostly for us:
Option A: Hands-Off Display Pet (What We Recommend)
Safest for the spider! Use a soft paintbrush to gently tap their back legs and guide them into a catch-cup whenever you need to clean.
Option B: Sit Flat on the Floor (Calm Docile Species Only)
If you do let a calm Curly Hair or Red Knee walk on your open palm, sit on the floor or bed so a sudden bolt can never mean a fatal drop to the floor.
3. Feeding by 'Booty Size' & The Molting Rule
Best Bugs & Big No-Nos:
Top pick—nutritious and won't bite a spider!
Great hunters—MUST remove uneaten crickets after 24h!
Crush worm heads so they can't hide underground
Wild bugs carry lawn sprays & parasites that kill spiders
4. Four Keys to a Happy, Thriving Brazilian Whiteknee Tarantula
Watch Out for Wire Mesh
Heavy ground tarantulas have two tiny hooks on each foot that can get snagged in cheap woven window-screen lids. Acrylic lids with drilled air holes are way safer!
Overflow the Water Dish
Tarantulas hate being sprayed in the face with a mister! Instead, just overfill their water dish a little bit once a week so one corner of the soil stays damp.
Itchy Belly Hairs
New World tarantulas kick itchy 'urticating hairs' off their butt when annoyed. Don't rub your eyes after working in the tank, and wash your hands with soap!
Upside-Down vs. Death Curl
Flat on their back = happy molting! Right-side-up with all 8 legs curled tightly *underneath* the belly = dehydrated ('death curl')—put their mouthparts right into a shallow puddle of water!
Bring-Home Shopping Checklist
Tap items to check them off on your phone while you shop at Critter Cabana.
Enclosure & Deep Soil
Water Dish & Safe Tools
Live Feeder Bugs
Complete Reference Notes & Oregon Keeping Guide
Species: Acanthoscurria geniculata | Difficulty: 2/5 — Easy | Hardiness: 4/5 — Hardy
Critter Cabana & Gresham Pet Supply — Keeping Your Pet Healthy & Thriving
At a Glance
| Common Name | Brazilian Whiteknee Tarantula | |
| Species | Acanthoscurria geniculata | |
| Origin | Tropical forests of Northern Brazil | |
| Adult Size | 7–8.5 inch leg span (A true giant) | |
| Lifespan | Females: 15–20 years | Males: 3–4 years |
| Diet Type | Insectivore (Crickets, Roaches, Mealworms) | |
| Activity | Nocturnal / Crepuscular (Highly visible display spider) | |
| Temperament | Bold, extremely fast, and highly defensive. | |
| Handleability | Absolutely not recommended. They are prone to kicking hairs and striking. | |
| Venom | Medically insignificant (Comparable to a bee sting, unless allergic) | |
| Urticating Hairs | Yes (They are notorious for having some of the most irritating hairs in the hobby) | |
| Difficulty | 2/5 — Easy (Care is simple, but their attitude requires respect) | |
| Hardiness | 4/5 — Hardy (Very robust and forgiving of mistakes) |
Why We Love Them: The Brazilian Whiteknee is a staple of the tarantula hobby. They grow into massive, heavy-bodied giants with jet-black bodies and striking, bright white bands wrapping around their leg joints. Because they rarely burrow as adults and prefer to sit boldly out in the open, they are widely considered one of the best "display" tarantulas available.
Safety Information
Venom/Defense: Their venom is medically insignificant. However, they are highly defensive and incredibly fast. Their primary defense is kicking massive clouds of urticating hairs, which are known to be particularly severe in this species. If they feel cornered, they will not hesitate to throw up a threat pose and bite.
First Aid: If you get hairs on your skin, use tape to pull them out, then wash with warm water. If you inhale them or get them in your eyes, seek medical attention.
Handling Precautions: Do not handle this species. They are heavy-bodied. If they bolt and fall to the floor, their abdomen will rupture and they will die. Always use long feeding tongs (10–12 inches minimum) when doing enclosure maintenance to protect yourself from hairs and strikes.
Housing & Enclosure
Enclosure Type & Size
- Type: Terrestrial / Opportunistic Burrower.
- Minimum: Because of their massive 8.5-inch size, a 20-gallon "long" tank or a 24x18x12 Exo Terra is recommended for an adult female.
- The Height Warning (CRITICAL): You must prioritize floor space over vertical height. If the enclosure is too tall, you must fill it with deep substrate so the distance from the dirt to the ceiling is no more than 1.5x the spider's leg span. A fall from the ceiling is fatal.
Substrate
- Recommended: Coconut fiber (Eco Earth), peat moss, or organic topsoil.
- Depth: Provide 4 to 6 inches of substrate. While adults prefer to sit out in the open, they still need the option to burrow, and the deep soil cushions them if they climb.
Décor & Enrichment
- Hides: Provide a massive, curved cork bark hide or half-log.
- Water Dish: Provide a large, shallow water dish. Keep it filled with fresh water at all times.
Temperature
| Zone | Temperature |
|---|---|
| Ambient | 72–82°F (22–28°C) |
- Heating: Room temperature is usually fine. If your house drops below 70°F, use a small heat pad mounted on the SIDE of the tank, never underneath.
Humidity
- Target Range: 65–80% (Moderate-High).
- How to Maintain: The goal is to keep the lower layers of the substrate slightly damp while allowing the top layer to dry out. The easiest way to achieve this is to overflow their water dish once a week. Ensure the enclosure has good cross-ventilation to prevent stagnant, swampy air.
Diet & Nutrition
The Brazilian Whiteknee has a legendary, ferocious feeding response. They grow fast and rarely refuse a meal unless they are molting. Warning: They will often attack the water stream when you refill their dish, mistaking it for prey.
Primary Diet
- Live crickets, dubia roaches, or mealworms. Ensure the prey is smaller than the spider's abdomen.
Feeding Schedule
| Life Stage | Frequency | Prey Size |
|---|---|---|
| Spiderling (Sling) | Every 4–5 days | Pinhead crickets or small mealworms |
| Juvenile | Every 5–7 days | Medium crickets |
| Adult | Every 7–14 days | 4-5 Large crickets or 2 Large Roaches |
Pre-Molt Fasting
- If they seal the entrance to their hide with webbing and dirt, and refuse food, they are in pre-molt. Do not disturb them.
Molting
During the Molt
- DO NOT disturb the spider. It will flip on its back to molt. It is not dead. Do not flip it over.
- Remove any live crickets from the enclosure immediately. A live cricket will eat a molting tarantula alive.
Post-Molt Care
- Wait at least 7–14 days before offering food. Because they are so massive, it takes a long time for their new fangs to harden. If they bite a cricket too soon, their fangs will break off and they will starve to death.
What We Stock & Use in Our Stores
These are products we carry and recommend for this species. Ask any associate for help finding them in-store.
| Category | Product | Notes |
|---|---|---|
| Enclosure | Aqueon 20-Gallon Long Tank | Prioritize floor space over height for this giant |
| Substrate | Zoo Med Eco Earth (Coco Fiber) | Minimum 4-6 inches deep |
| Hides | Zoo Med Natural Cork Bark (X-Large Curved) | The perfect starting roof for their hide |
| Tools | Zoo Med 10-inch Feeding Tongs | Mandatory to avoid their itchy hairs and feeding strikes |
| Water Dish | Exo Terra Shallow Water Dish (Large) | Overflow this once a week to keep the bottom soil damp |
Care sheet compiled by Critter Cabana & Gresham Pet Supply. For questions, ask any livestock specialist in-store.
Last updated: 2026-08-04
How We Keep Them at Critter Cabana & Gresham Pet Supply
- Oregon Winter Furnace Air vs. Molting Humidity: When Pacific Northwest furnaces kick on from October through April, indoor room humidity drops fast and dries out small enclosures from the top down. Rather than misting the spider or invert directly (which stresses terrestrial species and invites stagnant mold), we keep Brazilian Whiteknee Tarantula at
65-80% (Moderate-High)by using a deep moisture-retaining substrate bed (ReptiSoil + Coco Fiber + Sphagnum Moss), overflowing the water dish slightly into one corner, and maintaining cross-ventilation. - Safe Room Heating in the Willamette Valley: If your house drops below 65°F on winter nights, never stick a heat pad on the bottom of a burrowing invertebrate tank—they dig down to escape heat and will cook themselves. Use a low-wattage side-mounted heat mat on a digital thermostat or warm the room ambiently to
species-appropriate warm zone. - Stocked at Newberg & Gresham: At Critter Cabana (Newberg) and Gresham Pet Supply, we stock acrylic and glass invertebrate enclosures, cork bark flats and tubes, bioactive substrates, flightless fruit flies (D. melanogaster and D. hydei), pinhead to adult crickets, dubia roaches, and live Temperate White Springtail and Isopod cultures.
Common Questions (FAQ)
How do I keep my Brazilian Whiteknee Tarantula warm and humid enough during an Oregon winter?
Target species-appropriate warm zone and 65-80% (Moderate-High). When Oregon winter furnaces dry out the air, use a deep 3–5 inch substrate mix of Zoo Med ReptiSoil and coco fiber, keep a shallow water dish filled, and dampen one corner of the substrate rather than misting the animal directly. Never put a heat mat underneath a burrowing invertebrate enclosure.
What size enclosure does a Brazilian Whiteknee Tarantula need?
An adult Brazilian Whiteknee Tarantula thrives in 20-Gallon Long Tank with secure ventilation. For terrestrial tarantulas and scorpions, floor space and deep substrate matter most (keep open fall height low so heavy-bodied species cannot rupture their abdomen); for arboreal species, prioritize vertical cork bark tubes and cross-ventilation.
Can I put isopods in a Brazilian Whiteknee Tarantula bioactive enclosure?
Around molting tarantulas and scorpions, skip protein-hungry large isopods and stick to Temperate White Springtails (or gentle Dwarf White isopods in humid detritivore setups) so a soft, newly molted animal is never nibbled.
Where can I find Brazilian Whiteknee Tarantula, cork bark, and feeder insects in Oregon?
We stock live invertebrates, tarantulas, jumping spiders, cork bark flats and tubes, bioactive substrates, and gut-loaded feeder insects at our two exotic animal stores: Critter Cabana in Newberg (514 E First St, 503-537-2887) and Gresham Pet Supply (2185 NW Burnside Rd, 503-665-7606).
