A Complete Care Sheet for Brazilian Giant White Knee Tarantula

The Brazilian Giant White Knee Tarantula, scientifically known as Acanthoscurria geniculata is now one of the most popular pet spiders for beginners. Recent data shows that Acanthoscurria geniculata ranks among the top-selling beginner tarantulas, with their popularity skyrocketing due to their impressive 8-inch leg span and stunning black bodies adorned with brilliant white leg bands.

This simple care sheet for Brazilian Giant White Knee Tarantula will help you go from feeling unsure to feeling confident. You’ll learn the important facts, equipped with the scientific knowledge and practical skills needed to provide exceptional care for these magnificent creatures.

Image of Brazilian Giant White Knee Tarantula. Text written on the image-complete care sheet-Acanthoscurria geniculata

What Makes the Brazilian Giant White Knee Tarantula So Special?

Unlike many other tarantulas that like to hide, this bold species often stays out in the open, making it a great choice if you want a spider you can see and enjoy. Studies show that female tarantulas of this species can live up to 20 years in captivity. They also grow quickly, so you’ll get to watch them change a lot as they grow from tiny spiderlings into large, impressive adults.

Whether you’re excited by their strong feeding response, almost like wild predators or you’re just looking for a beginner-friendly tarantula, this care guide will give you all the information you need to help your spider live a healthy, happy life.

NOTE: This care sheet for the Brazilian Giant White Knee Tarantula is divided into six clear sections to make everything easy to understand. So grab your cup of coffee, take a relaxing sip, and let’s explore this guide step by step. By the end, you’ll have all the knowledge you need to care for this beautiful tarantula species with confidence.

Care Sheet for Brazilian Giant White Knee Tarantula

Section 1- Habitat Setup

The key to properly caring for a Brazilian Giant White Knee Tarantula is to recreate its natural habitat as closely as possible. These ground-dwelling tarantulas come from the humid rainforests of northern Brazil. In the wild, they dig burrows under logs and rocks in areas that receive more than 2,200mm of rain each year. By understanding where they come from, you can set up the perfect home for them in captivity.

AI generated representative image of brazilian giant white knee tarantula

Enclosure Size Requirements

When it comes to housing a Brazilian Giant White Knee Tarantula, floor space is much more important than height. Adult tarantulas need a minimum enclosure size of 45 x 45 x 30 cm (18 x 18 x 12 inches), but larger individuals do even better in enclosures measuring 60 x 45 x 30 cm.

Studies show that ground-dwelling tarantulas like Acanthoscurria geniculata can get seriously hurt if they fall from a height. That’s why it’s important to keep the enclosure’s height no more than 1.5 times the spider’s diagonal leg span. A general rule is that the enclosure should be 2 to 3 times the spider’s leg span in both length and width to allow comfortable movement.

For different life stages, use these guidelines:

Spiderlings (under 0.5″): 2-oz deli cups with ventilation holes
Juveniles (0.5-2.5″): 16-oz deli cups or small terrariums
Sub-adults (2.5-4″): Medium display boxes (30x20x15cm)
Adults (4-8″): Large terrariums meeting minimum size requirements

Substrate and Bedding Excellence

The substrate plays a very important role in the tarantula’s enclosure. It helps hold moisture, allows the spider to dig and burrow, and keeps the humidity levels just right. Studies show that a depth of 4 to 6 inches is ideal for adult Brazilian Giant White Knee Tarantulas.

The best type of substrate is a mix of different materials that together provide the right texture and hold moisture well. This creates a comfortable and healthy environment for your tarantula to live in.

Premium Substrate Mix Recipe:

40% coconut fiber (coco coir)
30% peat moss
20% vermiculite
10% organic potting soil for firmness

This mix provides the right balance between holding moisture and staying firm enough for burrowing. Studies have shown that coconut fiber is especially good at keeping humidity levels between 65% and 75%, which is important for healthy molting.

The substrate should feel slightly damp like soil that has been squeezed to remove extra water not wet or soggy. This helps create a safe and comfortable home for your tarantula.

Hideouts and Environmental Enrichment

Brazilian Giant White Knee Tarantulas, especially when young, love to dig and burrow. Giving them a proper hiding spot helps reduce stress and lets them behave naturally. A piece of cork bark that’s just a bit larger than the spider’s leg span works great.

Bury part of the cork bark in the substrate and place it in a corner of the enclosure. This creates a safe starting point for a burrow, which your tarantula will likely expand on its own.

Environmental enrichment means going beyond just giving your tarantula a place to hide. Adding leaf litter, small branches, and natural-looking decorations makes the enclosure more interesting and engaging for your spider.

Studies show that tarantulas living in more complex setups are 150% more active and explore more space compared to those in plain enclosures. Just be sure to avoid anything sharp, like cacti or hard rocks, as these can hurt the tarantula if it falls.

Section 2- Temperature & Humidity

Temperature and humidity control for brazilian giant white knee tarantula encloser — Photo by GFCPhotography/flickr

Optimal Temperature Ranges

Brazilian Giant White Knee Tarantulas do best in warm, steady temperatures that reflect their natural tropical environment. Studies show that the ideal daytime temperature is between 75–82°F (24–28°C) , while nighttime temperatures should stay around 68–72°F (20–22°C).

Most importantly, keeping the temperature stable is more important than hitting exact numbers. Sudden changes in temperature can stress your tarantula more than slightly off but in steady conditions. So, focus on maintaining a consistent climate in the enclosure.

Temperature Management Strategies

Avoid using heat lamps or under-tank heaters, as they can create hot spots and dry out the enclosure too much, which can be dangerous for your tarantula. If you need extra heat, it’s best to use a thermostat-controlled heat mat placed on the side of the enclosure, not underneath it.

In most cases, heating the whole room works well. Many tarantula keepers successfully maintain their spiders at room temperatures between 68–77°F (20–25°C).

Using a digital thermometer that records minimum and maximum temperatures helps you monitor the enclosure throughout the day. This allows you to spot any sudden changes in temperature that could stress your tarantula or affect its molting process.

Humidity Control and Monitoring

Keeping the right humidity level is very important for the health of a Brazilian Giant White Knee Tarantula. Studies show that a humidity range of 65–80% helps with proper molting and prevents dehydration.

To reach and maintain this humidity, you need to understand how ventilation, substrate moisture, and room conditions work together. Too much ventilation can dry out the enclosure, while too little can cause mold. Finding the right balance is the key to creating a safe and healthy environment for your tarantula.

Humidity Management System

The best way to keep humidity at the right level is to use more than one moisture source. A shallow water dish gives your tarantula something to drink and also helps add humidity to the air. Lightly misting one corner of the substrate once a week adds extra moisture without making the enclosure too wet.

The most important rule is to always provide good ventilation while keeping these moisture sources in place. This helps maintain a healthy balance between humidity and airflow, keeping your tarantula safe and comfortable.

Cross-ventilation is important because it stops mold from growing, which can happen when humidity is high and the air doesn’t move. To make sure air flows properly, your tarantula’s enclosure should have ventilation holes on opposite sides.

This setup allows fresh air to move through the enclosure while still keeping enough moisture inside. It helps create the same kind of environment found on the forest floor where these spiders naturally live and thrive.

Essential Monitoring Tools

Using accurate tools to measure temperature and humidity is a must for properly caring for a Brazilian Giant White Knee Tarantula. Digital hygrometers give you exact humidity readings, while devices that measure both temperature and humidity make things even easier by combining both functions.

Studies have shown that analog gauges are often inaccurate, which can lead to poor living conditions for your spider. That’s why investing in a digital instrument is smart and worth the investment for any serious tarantula keeper.

Place your temperature and humidity monitors away from water dishes and heat sources to get accurate readings of the overall enclosure. If they’re too close to heat or moisture, the results may not reflect the real conditions your tarantula experiences.

Many experienced keepers use more than one monitor in larger enclosures to check different areas, also known as microclimates. This helps make sure the entire habitat stays within safe and healthy ranges for your tarantula.

Section 3- Feeding & Nutrition

Feeding And Nutrition For Brazilian Giant White Knee Tarantula.

Diet Recommendations and Prey Selection

Brazilian Giant White Knee Tarantulas are well known for their big appetites and exciting feeding behavior. In the wild, they eat many types of invertebrates, including crickets, roaches, and even larger prey.

Studies show that feeding your tarantula a variety of foods helps prevent nutrition problems and supports better overall health. A mixed diet keeps them strong and helps them grow properly.

Primary Prey Item

Crickets: The most readily available and nutritionally complete option.
Dubia roaches: Higher protein content and longer shelf life than crickets.
Superworms: Excellent for larger specimens, though higher in fat.
Grasshoppers/locusts: Natural prey items with good nutritional profiles.

The size of the prey should be about three-quarters the length of your tarantula’s body (not including the legs). This makes it easier and safer for the spider to catch and eat its food and get the nutrition it needs.

Avoid feeding prey that is too big, as it can hurt or stress your tarantula. Feeding the right size helps keep your spider healthy and safe.

Advanced Feeding Considerations

Recent care studies show that pre-killed prey is a good option for young spiderlings and shy or nervous Brazilian Giant White Knee Tarantulas. For confident adult tarantulas, live prey is better because it encourages natural hunting behavior.

Always remove any uneaten prey within 24 hours. This helps reduce stress for your tarantula and keeps the enclosure clean and safe.

Feeding Schedule and Frequency

How often a spider is fed depends a lot on its age, size, and metabolism. Studies show that how fast a spider grows is closely linked to how often it eats and the temperature it’s kept at. For example, spiderlings fed every 3 to 4 days at a temperature of 80–85°F can grow to nearly a 4-inch leg span in their first year.

Age-Based Feeding Schedule

Spiderlings (under 1″): Every 3-4 days with pre-killed or very small live prey
Juveniles (1-3″): Every 5-7 days with appropriately sized crickets or roaches
Sub-adults (3-6″): Weekly feeding with 2-3 large prey items
Adults (6+ inches): Every 7-10 days with 5-7 adult crickets or 2-3 large roaches

Molting Considerations

It’s common for the Brazilian Giant White Knee tarantula (Acanthoscurria geniculata) to refuse food for 1 to 4 weeks before molting. This period of fasting is known as pre-molt anorexia and it is a natural part of the molting cycle and should not be mistaken for illness or stress. Never attempt to force-feed a tarantula showing molting signs, as prey items can seriously injure vulnerable, soft-bodied spiders during the molting process.

Hydration and Water Requirements

Maintaining proper hydration is essential for the health of the Brazilian Giant White Knee tarantula (Acanthoscurria geniculata). It is recommended to change the water dish at least twice a week—or more frequently if the tarantula defecates in it. Always use dechlorinated or bottled water, especially if your tap water contains high levels of chlorine. Many experienced keepers opt to add aquarium-safe water conditioners to neutralize potentially harmful chemicals.

A well-hydrated tarantula typically has a plump, rounded abdomen and displays normal levels of activity. In contrast, signs of dehydration include a shrunken, wrinkled abdomen and lethargic behavior. Severely dehydrated individuals may immediately approach the water source and drink for extended periods. Providing clean, accessible water at all times is a critical component of responsible tarantula care.

Section 4- Handling & Behavior

Handling and Behavior of Brazilian Giant White Knee Tarantula. A pet tarantula on the hand image.

Handling Safety Protocols

Handling the Brazilian Giant White Knee tarantula (Acanthoscurria geniculata) is strongly discouraged by arachnid experts and exotic animal veterinarians. This species is known for its large size and bold temperament, and it possesses several effective defensive mechanisms that make direct interaction risky for both the spider and the keeper. Unlike more docile tarantulas, A. geniculata readily deploys urticating hairs and may deliver defensive bites when it feels threatened.

Scientific observations and keeper reports indicate that this species often exhibits defensive rather than evasive behavior. When confronted, they are more likely to stand their ground than flee, making their reactions during handling attempts highly unpredictable. Additionally, adult females are particularly strong, some have been observed lifting enclosure lids if given enough leverage. Their power, coupled with their defensive instincts, makes minimal handling the safest and most ethical approach when caring for this impressive New World species.

Safe Maintenance Techniques

Routine enclosure maintenance for the Brazilian Giant White Knee tarantula (Acanthoscurria geniculata) should be performed with caution due to the species’ strong feeding response and defensive nature. When cleaning or performing other tasks inside the enclosure, use long-handled tools such as 12-inch feeding tongs or soft paint brushes to gently guide the tarantula away from the work area. These spiders are known to lunge at moving objects, mistaking them for prey, and may attempt to bite or subdue tools during maintenance.

For personal safety, always wear protective clothing, including long sleeves, gloves, and eye protection, especially when working in close proximity to the spider. This not only reduces the risk of bites but also minimizes exposure to urticating hairs, which can cause skin and eye irritation.

In the event of an emergency rehousing, avoid direct contact. Use catch cups or clear plastic containers to safely contain the spider. Experienced keepers also recommend preparing escape-proof backup enclosures before opening the primary habitat. Having all necessary tools and containers on hand greatly reduces stress for both the tarantula and the keeper during sudden relocations.

Behavioral Signs and Communication

Understanding Brazilian Giant White Knee behavior is crucial for proper care and safety. These spiders communicate through distinct postures and actions that indicate their emotional state and intentions.

Defensive Postures

Threat display: Rearing on hind legs with front legs elevated and fangs exposed
Hair kicking: Rapid rubbing of hind legs against the abdomen to release urticating hairs
Retreat positioning: Backing into corners or hides while facing the threat

Normal Behavior

Active hunting: Moving around the enclosure, particularly in evening hours
Web spinning: Creating silk mats for molting or territorial marking
Substrate rearrangement: Digging and moving substrate to create preferred topography

Pre-molt Indicators

Research identifies several reliable pre-molt signs that indicate approaching ecdysis:

Refusal to eat for 1-4 weeks
Increased webbing activity, particularly creating molting mats
Darkening of the abdomen as the new exoskeleton develops underneath
Decreased activity and increased hiding

Stress Prevention Strategies

Environmental stability is the most effective stress prevention strategy. Brazilian Giant White Knees respond poorly to frequent disturbances, bright lighting, and temperature fluctuations. Position enclosures in quiet areas away from high-traffic zones and avoid unnecessary maintenance.

Minimizing Stress Factors

Maintain consistent temperature and humidity levels
Avoid bright lighting or sudden illumination changes
Reduce vibrations from music, television, or heavy foot traffic
Keep maintenance schedules predictable and brief
Provide adequate hiding spaces for security

Scientific research demonstrates that tarantulas housed in complex environments with multiple hiding options and enrichment items show reduced stress indicators compared to sparse setups. However, balance enrichment with the spider’s need for secure, undisturbed spaces.

Section 5- Health & Maintenance

Health and Maintenance of Brazilian Giant White Knee Tarantula.

Common Health Issues and Recognition

Dehydration

Captive Brazilian Giant White Knee tarantulas can experience several health issues, the most common being dehydration. Clinical signs of dehydration include a shrunken, wrinkled abdomen, lethargy, and a noticeable reduction in body mass. A dehydrated tarantula will often respond eagerly when presented with water, sometimes drinking for extended periods to restore proper hydration levels. Ensuring constant access to clean, dechlorinated water is essential for preventing this condition.

Dysecdysis

The second most frequently observed issue is molting complications, particularly dysecdysis (incomplete molts). Research and keeper data suggest that humidity levels below 60% significantly increase the risk of molting failure. Inadequate substrate depth may also interfere with proper molting posture, increasing the likelihood of trapped limbs or exoskeletal deformities. Dysecdysis can be fatal if not promptly addressed, highlighting the importance of correct environmental parameters.

Bacterial Infections

Although rare, secondary bacterial infections can occur, especially in association with bite wounds, abrasions, or incomplete molts. Symptoms may include localized swelling, discoloration, and unusual discharge around affected areas. These cases require immediate attention and may necessitate consultation with an exotic animal veterinarian to prevent systemic infection and further complications.

Section 6- Molt Care and Support

Molting represents the most vulnerable period in a Brazilian Giant White Knee’s life cycle. Adult females continue molting throughout their lives, making proper molt care essential for long-term health. Pre-molt preparation and post-molt monitoring require specific protocols to ensure successful ecdysis.

Molt Care and Support For Brazilian Giant White Knee Tarantula.

Pre-molt Environment Preparation

Increase humidity to 75-80% through additional substrate misting
Remove all prey items to prevent attacks on vulnerable spiders
Ensure water dish remains accessible but not overly large
Minimize disturbances and avoid enclosure maintenance

During Molting Process

Never disturb a molting spider or attempt to assist the process. The molting tarantula will flip onto its back and remain motionless for 6-24 hours while extracting itself from the old exoskeleton. This position is normal and does not indicate distress or death.

Post-molt Recovery

Newly molted spiders remain vulnerable for 5-7 days while the new exoskeleton hardens. During this period:

Maintain higher humidity levels (75-80%)
Avoid any handling or disturbances
Do not offer food until the exoskeleton fully hardens
Monitor for incomplete molts or stuck appendages

The discarded exoskeleton (exuvia) can remain in the enclosure or be removed for preservation. Some spiders manipulate or partially consume the old skin, which is normal behavior.

Conclusion

To care for a Brazilian Giant White Knee tarantula, maintain a warm, humid enclosure (75–85°F, 65–80% humidity) with a deep substrate for burrowing. Feed appropriately sized insects 1–2 times per week, adjusting for age and molt cycle. Provide clean, dechlorinated water and avoid handling due to their defensive behavior. Proper ventilation, regular maintenance, and monitoring for dehydration or molting issues are essential for long-term health.