Acanthoscurria geniculata
Brazilian White Knee Tarantula: Advanced Care Guide
Keeper Snapshot: A bold, fast-growing terrestrial with a huge feeding response and impressive adult size: 7-9 inches across, with females living roughly 12-20 years.
Group: TarantulasDifficulty: Spice 3: IntermediateSetup: Large terrestrialHandling: Not recommended
Use This Guide Safely
- Confirm the exact animal. Match this guide to the species, locality, size, and life stage on your label. If the ID is uncertain, use the more conservative part of the range and ask before changing the setup.
- Change one thing at a time. Treat temperature and humidity as target zones, then watch posture, burrowing, drinking, feeding, and molt behavior before making another adjustment.
- Respect the handling boundary. If the guide says no handling, fast, defensive, or medically significant, plan transfers with catch cups, locked lids, and no bare hands. For serious bites, stings, or symptoms, seek emergency medical care.
Quick Snapshot
| Temperature | 75-82°F |
|---|---|
| Humidity | Moderate ambient (60-75%) with cross ventilation; damp lower substrate, drier surface, large dish |
| Setup Type | Large terrestrial |
| Substrate | Moderately deep soil/coco mix |
| Feeding | Strong feeder; weekly |
| Care Difficulty | Spice 3: Intermediate |
| Handling | Not recommended |
Humidity zones: Very Low under 30% - Low 30-60% - Low-Moderate 40-70% - Moderate 60-80% - Moderate-High 70-85% - High 80%+ - Very High 90%+
Enclosure Format / Size Class
- Compact secure enclosure while it's a tiny sling
- Horizontal terrestrial burrow setup for juveniles
- Larger floor-space terrestrial build for the adult
Warnings First
- Strong feeding response
- Kicking hairs
- Needs room as it grows
- A big bold eater fouls a still enclosure fast. Cross ventilation low on two opposite walls keeps boluses and damp substrate from turning into a mold problem.
Simple Care
- Feed well but do not power-feed into obesity.
- Keep a water dish available. Put pebbles in it so slings cannot drown.
- Cross ventilation low on two opposite walls; moderate moisture only works with air moving through it.
- Expect bold behavior.
Advanced Keeper Notes
Enclosure & Microclimate
- Moderate substrate moisture is helpful, especially for juveniles, but the enclosure should not be stagnant.
- Adults need substantial floor space and a water dish. They may rearrange hides and substrate.
- Making that non-stagnant is a matter of vent placement rather than vent count. Put vents low on two opposite walls, at or just above the substrate, so air crosses the floor where the moisture and the spider both are. On a large-footprint terrestrial, lid-only venting leaves the far corners of the floor still, and with a heavy feeder those are the corners where boluses and damp substrate sit.
- Ventilation and ambient humidity trade against each other. Hold 60 to 75% by keeping the lower substrate damp and running a large dish, then let the vents flow freely. Do not close the enclosure up to raise the number; on a species that eats and defecates as much as this one, still humid air fouls quickly.
- Judge by hand rather than by gauge. The lower substrate should be damp enough to hold shape when squeezed with no free water, the surface allowed to look drier. If the surface never dries between waterings, the enclosure needs more airflow.
- Keep a large water dish and put pebbles or flat stones in it so the waterline sits below the rim. Slings drown in dishes, and on a fast-growing species keepers often move up to an adult-sized dish before the spider is really adult-sized. The stones also stop escaped feeders from fouling the water, which matters more on a heavy feeder.
- Mist the substrate under the hide rather than across the whole floor. That keeps a humid pocket where a juvenile retreats while the open floor stays drier and keeps exchanging air, which is what stops a bold, messy eater's enclosure from going sour.
Feeding, Growth & Maintenance
- This is a high-growth, high-food-response species. Use tongs and avoid startling it during maintenance.
- Feeding schedule: slings 2×/week; juveniles every 7-10 days; adults every 1-2 weeks (it's a heavy feeder). Keep prey smaller than the abdomen, and read body condition: feed more often if the abdomen is thinner than the widest part of the carapace, less often if it's plump.
- Molting: even a bold White Knee turns sluggish, hides up, and stops eating for days or even weeks before a molt. Normal. Pull uneaten feeders, leave it alone, and wait 5-10 days after the molt before feeding again.
Possible Origin / Range
- Likely native range: Northern Brazil and Amazonian forest regions.
- Habitat translation: Moisture-retentive terrestrial substrate with ventilation and a large water source.
Advanced Keeper Details
- High food response means feeding and water changes should be deliberate and tool-based.
- Adults are strong remodelers; use stable hides and expect substrate movement.
- Adult size ~7-9 in DLS; a fast grower, on par with Lasiodora parahybana; females ~12-20 years, males ~3-5.
- Kicks urticating hairs readily: irritation varies person to person, but several keepers rate it on a par with or worse than Brachypelma.