Giant White Knee Tarantula Care Guide (Acanthoscurria geniculata)
The Giant White Knee is one of the most visually striking tarantulas in the hobby. Large, fast-growing, and boldly patterned with bright white knee markings against a dark body, it's a popular choice for keepers who want a large New World species with serious visual impact. It is not a beginner tarantula — it is defensive, fast, and has urticating hairs — but it is well within reach for intermediate keepers who understand what they're working with.
Species Overview
- Scientific name: Acanthoscurria geniculata
- Common name: Giant White Knee Tarantula, White Knee Tarantula
- Origin: Brazil (Amazon basin)
- Adult size: 7–8+ inches legspan; one of the larger New World species
- Lifespan: Females 15–20+ years; males significantly shorter
- Experience level: Intermediate
- Temperament: Defensive; will kick urticating hairs readily and may threat-pose; not a handling tarantula
- Type: Terrestrial/opportunistic burrower
Enclosure
Adults require a terrestrial enclosure with more floor space than height. A 10–15+ gallon equivalent footprint is appropriate for adults. Cross-ventilation is important — front and side vents or a mesh panel combined with a ventilated lid. Avoid purely top-ventilated enclosures that create stagnant air at substrate level.
Juveniles can be housed in smaller enclosures and moved up as they grow. The Giant White Knee grows relatively quickly compared to many other species.
→ Best Tarantula Enclosures | What Size Enclosure Does a Tarantula Need?
Substrate
A deep, slightly moist substrate mix works well — coconut fiber as the base, optionally mixed with topsoil and/or peat. Depth of 4–6+ inches allows for burrowing behavior, though many individuals will use a hide rather than burrow extensively. Keep the substrate slightly moist at depth while allowing the surface to dry between mistings.
Temperature
72–82°F (22–28°C). Room temperature in most homes is adequate. Avoid sustained temperatures above 85°F. No supplemental heating is required in most indoor environments.
Humidity
Maintain moderate moisture by keeping the lower substrate layers slightly moist while allowing the surface to partially dry. Keep a water dish available at all times and provide good ventilation. Avoid keeping the enclosure constantly wet or saturated. Good ventilation helps reduce stagnant, overly wet conditions and mold growth.
Hides and Decor
Provide at least one hide. Cork bark tubes or half-logs work well. The Giant White Knee will often spend time in the open once established, making it a good display species despite its defensive temperament.
→ Best Tarantula Hides | Best Cork Bark for Tarantulas | Best Tarantula Decor
Water
Provide a shallow water dish at all times. Size the dish to the tarantula — it should be able to drink without risk of drowning. Clean and refill regularly.
Feeding
An enthusiastic feeder. Adults can take large crickets, dubia roaches, or other appropriately sized prey. Feed adults every 1–2 weeks; juveniles more frequently. Remove uneaten prey within 24 hours. Do not feed during pre-molt.
Molting
The Giant White Knee molts relatively frequently as a juvenile and sub-adult given its fast growth rate. Pre-molt signs include food refusal, lethargy, and darkening of the abdomen. Remove all live prey before and during molt. Do not disturb during the molt process.
Handling
Not recommended. The Giant White Knee is defensive, fast, and kicks urticating hairs aggressively when threatened. Urticating hairs from Acanthoscurria species are considered more irritating than many other New World species. Use a catch cup for enclosure maintenance rather than direct handling.
Temperament and Behavior
Defensive and fast-moving, particularly as juveniles. Adults often settle somewhat but remain unpredictable. Threat-posing (rearing up with front legs raised) is common when disturbed. Despite its defensive nature, it is often visible in the enclosure and makes an excellent display animal.
Common Health Issues
→ Common Tarantula Health Problems
Is the Giant White Knee Right for You?
The Giant White Knee is an excellent choice for intermediate keepers who want a large, fast-growing, visually impressive New World species and are comfortable with a defensive animal. It is not suitable for keepers who want to handle their tarantula or who are new to the hobby. If you want a large New World species with a calmer temperament, consider the Curly Hair Tarantula or Chaco Golden Knee instead.