Acanthoscurria geniculata (Brazilian White Knee)
Last updated: May 13, 2026
This is not a care guide. If you are interested in keeping this species, please research its husbandry thoroughly before purchasing. Tom's Big Spiders has species-specific husbandry notes that are a solid place to start.
Acanthoscurria geniculata is one of the most visually striking large new world tarantulas available in the hobby. It has a jet black body covered in dark setae, with sharply contrasting white banding at the knee joints. The effect is clean and dramatic, and a full-grown female is genuinely impressive to look at. Native to Brazil, this species can reach 8 to 9 inches in legspan, putting it among the larger spiders you will encounter regularly.
It is a terrestrial burrowing species in the wild, and in captivity it will often take advantage of deep substrate to dig, though it can also be kept with minimal depth if you prefer it more visible.
Temperament
This is where the Brazilian white knee differs from something like a Chaco golden knee or a rose hair. It is not a particularly calm species. It has a reputation for being more reactive than your average docile new world, and it will flick urticating hairs with some enthusiasm. Not every individual is the same, and some settle down considerably once established in their enclosure, but going in expecting a more lively spider is the right approach.
It is not a difficult species to keep or work around by any objective measure. It does not have venom that is a serious concern, and a calm, deliberate approach to enclosure maintenance will get you through routine husbandry without drama most of the time. But it will keep you more attentive than a Brachypelma or Grammostola would.
Growth Rate
One appealing aspect of A. geniculata is that it grows faster than many of the other large new world species. Compared to Grammostola, which can take a decade to reach full size, the Brazilian white knee is a faster trip to an impressive adult. You are still talking multiple years from spiderling to adult, but the timeline is more satisfying for keepers who find the ultra-slow Grammostola growth frustrating.
Is This a Good Fit for You?
If you have kept a few tarantulas and want to add something with more visual impact and a bit more personality than your docile beginners, the Brazilian white knee is a strong choice. It is widely available, reasonably priced, and looks unlike most other tarantulas in a collection of comparable species.
If this would be your first or second tarantula, you might want to start with something calmer and come back to it. Not because it is dangerous, but because the slightly more reactive temperament is easier to manage once you have some experience. Once you are comfortable working around a spider that may respond to your presence, this one is very manageable.
Current Prices
FAQs
Is the Brazilian White Knee good for beginners?
It is on the edge. Its temperament is more reactive than a Grammostola or Brachypelma, which makes it a better fit for keepers who have some experience with tarantulas already. That said, it is still a new world species with predictable behavior, and careful keepers can certainly handle it. It is not a dangerous spider.
How big does Acanthoscurria geniculata get?
Females typically reach 8 to 9 inches in legspan. It is one of the larger new world species available in the hobby and looks especially impressive because of the high contrast between the black body and the white knee bands.
Does the Brazilian White Knee burrow?
It can, particularly as a younger specimen. Adults in captivity are somewhat variable: some will dig extensively and some will not. Providing the option without requiring it works well.
Does Acanthoscurria geniculata have urticating hairs?
Yes, and it uses them. This is a new world species and like most new world tarantulas it will kick urticating setae as a primary defense. Some individuals are more prone to this than others, but it is worth being aware of when working around the enclosure.