Grammostola grossa (Guarani Giant Tarantula)

Grammostola grossa (Guarani Giant Tarantula)

The Guarani Giant, or Grammostola grossa, is a terrestrial tarantula from Brazil, Paraguay, Uruguay, and Argentina. Adults of this species have a deep, almost black coloration dusted with a fine silver hue throughout, creating a beautiful high contrast coloration all its own. Even as spiderlings, it carries the same dark, fuzzy look as its cousins Grammostola actaeon and Grammostola iheringi, though grossa never develops their signature red abdomen, staying an even silver-dusted black instead. Spiderlings do not start out colorful and the adult colors come in around 2 to 2.5 inches, while the species only grows to about 7 inches in diagonal leg span. Like others in the genus, this species has a very long lifespan, with females reaching about 20 to 30 years while males live 3 to 5 years. This species is also very calm and forgiving, and one we recommend for beginner keepers or anyone who wants an easier keeping experience. Grab this docile new world tarantula for sale today, with every size we carry listed below.

Why do hobbyists keep Grammostola grossa?

• Stunning Coloration: A deep, almost black body dusted with fine silver hairs, a frosted look that stands apart from other dark Grammostola species.
• Fluffy Appearance: Both slings and adults carry a noticeably fuzzy coat, a softer, less intimidating look than most Grammostola.
• Large Size: One of the larger Grammostola species in the hobby, reaching about 7 inches at full leg span.
• Fast Grower: Hatches out unusually large, nearly an inch in leg span, giving it a head start that carries through to a quicker climb to full size.
• Great Beginner Species: Fast growth aside, this genus has a strong track record with keepers who start from a spiderling, forgiving enough that the ordinary early slip-ups rarely set the animal back.
• Rare in the Hobby: Not often available and quick to sell out when it is.

How should Grammostola grossa be kept?

• Adult Size: Hatches at around 0.5 to 0.75 inch and reaches about 7 inches at full leg span, one of the larger Grammostola species in the hobby.
• Enclosure: Provide roughly 3 to 4 times the leg span as footprint and 2 times the leg span as height, with substrate at least as deep as the leg span. Pick a size above for that tier's exact setup.
• Temperature: Keep between 65 to 75 degrees F.
• Humidity: Maintain a moisture gradient with a slightly damp lower layer and a drier surface, similar to a morning dew cycle in the wild. Good ventilation is critical.
• Water: A shallow textured water dish works well, something they can grip when climbing out.
• Diet: Crickets, roaches, and similar feeders sized to the carapace (head). Pick a size above for that tier's exact prey measurement.
• Temperament: Calm and easygoing, a great pick for beginners who want a docile, low-key display animal that grows quickly.

Which size should I choose?

• 0.75-1" Spiderling: your cheapest way to collect this species, though the silver-dusted coloration hasn't come in yet at this size.
• 1-1.25" Spiderling: a well-started spiderling, past the size the species hatches at, with the color change still ahead.
• 2-2.5" Juvenile: right around the size where the silver-dusted coloration starts coming in.
• 2.5-3" Juvenile: past the color-change window, with the frosted black adult look typically well established.

Are there any additional notes or considerations for Grammostola grossa?

• Captive Bred: All tarantulas at Exotics Unlimited are captive bred.

Frequently asked questions about Grammostola grossa

• Is the Guarani Giant related to the Black Yeti or Entre Rios? They are three distinct species, but the resemblance is real. All three are Grammostola cousins from an overlapping range in Brazil and Uruguay, and grossa's spiderlings carry that same dark, fuzzy look. The difference shows up in color: grossa never develops the black-and-red contrast the other two carry, staying an even silver-dusted black all the way to adulthood.
• How big does the Guarani Giant get? Adults reach about 7 inches in diagonal leg span, one of the larger species in the Grammostola genus.
• When does the silver-dusted coloration come in? Spiderlings do not start out colorful. The adult coloration typically develops around 2 to 2.5 inches in diagonal leg span.

Looking for similar species?

• Browse our New World Tarantulas and Terrestrial Tarantulas collections to explore related care profiles and species groupings.