A large, calm New World terrestrial tarantula with dark legs marked by golden-yellow striping at the knees. Docile, hardy, and long-lived, it is one of the best beginner species for keepers wanting a big spider.
ℹ️
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Large; leg span about 6-8 in (15-20 cm), robust heavy-bodied build.
Lifespan
8–20 years
Social needs
solo
Native region
Gran Chaco region of Paraguay and Argentina (dry grassland and scrub)
Origin
New World
Climate
⛅ Subtropical
Family
Theraphosidae
Genus
Grammostola
Part of the Tarantulas
Theraphosid spiders kept as low-maintenance display invertebrates. New World species are generally docile with mild venom but bear irritating urticating hairs, while Old World species lack those hairs but tend to be fast, defensive, and have more potent (though rarely life-threatening) venom.
From the minimum an animal needs to be kept humanely, up to the ideal setup. Bigger is almost always better — minimums are floors, not targets.
Photo coming soon
Minimum
Juvenile / sub-adult enclosure
8 × 8 × 8 in (juvi) → 10 × 10 × 8 in (sub-adult)
Clear acrylic or glass enclosure with cross-ventilation, 3–4 in of dry coco-fibre or topsoil mix, a cork-bark hide, and a shallow water dish. Floor space matters more than height for terrestrials; the spider should be able to turn around comfortably. Chaco golden knees are large, calm Grammostola from Paraguay — dry substrate with a single damp corner is ideal.
Photo coming soon
Recommended
Adult terrestrial enclosure
12 × 12 × 8 in (≈ floor 3× adult DLS)
Adult floor space targets roughly three times the diagonal leg span so the spider can web, walk, and ambush. Add 4–5 in of substrate, a half-log hide, low decor, and a water dish; height stays modest to prevent a fatal fall onto the abdomen.
Photo coming soon
Ideal
Naturalistic terrestrial vivarium
14 × 10 × 10 in, bioactive
A bioactive footprint with deeper substrate (5–6 in), leaf litter, a sculpted hide, and one or two live hardy plants. Cleanup crew (springtails, isopods) keeps the dry-but-not-arid microclimate stable for long-term welfare.
Life & growth stages
How this animal changes through its life — each stage often has its own care, diet and space needs.
Photo coming soon
Egg
These invertebrates lay eggs — often in a guarded clutch, a silk sac (spiders), or a brood (carried by female isopods). The eggs are small and soft and develop without a true larval or pupal transformation.
Photo coming soon
Juvenile
Juveniles hatch as miniature versions of the adult and grow by molting their exoskeleton (or, in snails, by enlarging the shell). They gain size, segments, or leg pairs and gradually take on adult coloration with each molt.
Adult
Adults reach full size and reproductive maturity with the species' mature form and coloration. Many arachnids and myriapods continue to molt as adults, and sexes can differ in size or in specialized appendages.
Habitat & enclosure
House one spider alone in a terrestrial enclosure with generous floor space; a 10-15 gallon footprint (about 24x12 in / 60x30 cm) suits a large adult. Floor space matters more than height, and climbing distance should be kept low to prevent falls. Provide a cork-bark hide and a shallow water dish. Keep at 72-82F (22-28C). This dry-tolerant species needs mostly dry substrate with one slightly damp corner; a full water dish supplies ambient humidity. No UVB or special lighting is required.
Substrate
Use 3-6 in (8-15 cm) of a coco-fiber and topsoil mix, optionally with a little sphagnum, deep enough for shallow burrowing. Keep it mostly dry with one lightly moistened area, and spot-clean boluses and feces to prevent mold.
Equipment & setup
No heat source is needed if the room stays around 72-80F; if supplemental heat is required, use a thermostat-controlled side-mounted heat mat, never underneath. No UVB. A ventilated terrarium with good floor space, a cork-bark hide, and a shallow water dish complete the setup. A hygrometer is optional given the dry-tolerant care.
Diet
An opportunistic insectivore with a hearty appetite. Feed appropriately sized feeders (no larger than the spider's body length): crickets, dubia roaches, mealworms, superworms, and the occasional larger feeder for adults. Slings eat 2-3x weekly, juveniles weekly, adults every 1-2 weeks. Remove uneaten prey within 24 hours and withhold food during premolt (darkened abdomen). Always provide fresh water.
Behavior & temperament
A docile, slow-moving New World species and a classic 'big and calm' beginner tarantula. It rarely shows defensiveness and is more likely to flee or flick urticating hairs than to bite. Venom is medically insignificant (bee-sting level). Handling is best minimized for the spider's safety, since a fall from this heavy-bodied spider can rupture the abdomen, but among large species it is one of the more tolerant if handled low to the ground.
Health
Hardy and long-lived; females can reach roughly 20 years while mature males live only a year or two after their final molt. Watch for dehydration (curled legs, lethargy) and keep the water dish full. Bald abdomen patches from hair-flicking regrow at the next molt. Avoid falls, soggy stagnant substrate (mold and mite risk), and handling during molt. A spider on its back is molting, not dying; leave it undisturbed.
Tips, DIY & hacks
Expect slow, steady growth, so buy a juvenile or sub-adult if you want size sooner. Give it a wide, low enclosure rather than a tall one to prevent dangerous falls. Keep handling to a minimum and stay near the ground if you do. Its size combined with a gentle temperament makes it an excellent confidence-builder for new keepers.
