Theraphosa

Theraphosa is a genus of giant South American tarantulas first established by French arachnologist Charles Athanase Walckenaer in 1805, with the type species originally described a year earlier by Latreille as Mygale blondi (now Theraphosa blondi). These enormous spiders quickly became famous as the “Goliath birdeaters” after 18th–19th century illustrations showed large tarantulas preying on small birds, a dramatic image that cemented their common name even though they mostly feed on invertebrates and small vertebrates.

For nearly two centuries T. blondi was the only recognized member of the genus. In 1991, Andreas Tinter described Pseudotheraphosa apophysis, which was later moved into Theraphosa by Rogério Bertani in 2001, becoming Theraphosa apophysis. In 2010, Rudloff and Weinmann described Theraphosa stirmi, a third giant “Goliath” species that had long been confused in the hobby with T. blondi.

Modern taxonomic work continues to refine the group. The World Spider Catalog currently lists several species in the genus, including T. blondi, T. apophysis, T. stirmi and T. spinipes, the latter transferred into Theraphosa from Lasiodora in 2023. As research progresses and new material from remote rainforest habitats is studied, the genus remains an active subject of revision and discovery in theraphosid systematics.

Theraphosa stirmi

• Common name: Burgundy Goliath Bird-eater (also “Burgundy Goliath Birdeater”)

• Origin: Tropical lowland rainforests of northern South America – primarily Guyana, Venezuela, northern Brazil, French Guiana, and Suriname.

• Lifestyle / type:

  • New World terrestrial, fossorial-leaning tarantula

  • Opportunistic burrower using deep burrows or abandoned mammal holes on the forest floor

• Adult size:

  • Among the largest spiders in the world

  • Typical adult legspan 9–11 in (23–28 cm), with large females sometimes approaching 12 in (30 cm)

• Growth rate:

  • Medium to fast for a large terrestrial species

  • Males mature faster; females take several years to reach full size but live much longer

• Temperament:

  • Generally defensive / nervous, not recommended for handling

  • Quick to use threat postures, hissing/stridulation, and urticating hairs; capable of a strong bite if provoked

• Color & appearance:

  • Massive, heavy-bodied tarantula with a very broad carapace

  • Overall color from rusty to rich burgundy-brown or dark chocolate brown, especially vivid after a fresh molt

  • Reddish hairs on legs and abdomen with lighter cream to tan leg striping

  • Spiderlings and juveniles show distinctive pink “feet” (tarsi) on the front legs that fade with age

Species History

Theraphosa stirmi, commonly known in the hobby as the Burgundy Goliath Bird-eater, is the most recently described member of the giant Theraphosa genus. The genus was historically represented only by T. blondi (described in 1804) and later T. apophysis (1991). T. stirmi completed the trio when it was formally described by Jan-Peter Rudloff and Dirk Weinmann in 2010.

For more than a decade before its description, this spider circulated in the pet trade under names like Theraphosa sp. “Burgundy” and was frequently misidentified and sold as T. blondi. Closer examination of wild-collected material from Guyana in the late 2000s revealed consistent differences, leading to its recognition as a distinct species.

The official type locality for T. stirmi is in the Essequibo region of Guyana (Takutu River area), and the species is now recorded from parts of Guyana and northern Brazil in lowland rainforest habitats. Compared with its close relatives, T. stirmi is characterized by rich rusty-to-burgundy tones, pale leg striping and distinctive juvenile coloration (notably pink tarsi), features that help separate it from T. blondi and T. apophysis in both the field and the hobby.

Natural Habitat

Theraphosa stirmi is native to the tropical lowland rainforests of northern South America, with confirmed populations in Guyana and northern Brazil, and likely extending into neighboring Venezuela. It occurs below about 1000 m elevation, in hot, humid forest where temperatures are warm year-round and rainfall is high.

In the wild, this species is an opportunistic burrower, living in deep self-dug burrows or taking over abandoned rodent holes on the forest floor. The ground is typically covered in leaf litter, roots, and rotting wood, which provide structure for burrows and shelter. These spiders are nocturnal ground predators, emerging at night to hunt insects and other invertebrates, and occasionally small vertebrates.

Our Specimen:

Given name: Crimson, aka "dickhead"

Sex: Possible male

Life stage: Adult

• Approximately 8 to 8.5 in

• Deceptively fast, can be bolty

• Always eats.

• Generally well-mannered now but intimidating.

• Has secured a place in my heart

Genus and species: Theraphosa blondi

Common name: Goliath bird eater

Given name: Maple

This is a huge species of tarantula found in the northern areas of South America, and may reach 10 to 12 inches or more. They are surprisingly quick for their size, and may threat pose or kick hairs if disturbed. These are the largest spiders in the world by mass. There are reports of T. blondi consumption as part of local cuisine.

Habitat: They are from humid and tropical regions in the Amazon rainforest and dig deep burrows. They are believed to be moisture dependent in captivity.

Husbandry Notes:

Enclosure: 12x12x12

Sex: Undetermined

Life stage: Juvenile

Size: Approximately 4.5 in

Growth: Modest thus far, molted in April 2025

Disposition: Periods of aggressiveness but generally well-mannered

Eating habits: Typically an aggressive eater, but has periods of complacency

Misc: Has been pretty slow in putting on size.

Genus and species: Theraphosa aphophysis

Common name: Goliath pink toe birdeater

Given name: Clover

This is a huge species of tarantula from Venezuela that can reach 10 to 12 inches. They are surprisingly quick for their size, and may threat pose or kick hairs if disturbed. This species has pink shading at the end of their legs as juveniles. They tend to be a little more skittish than blondi's and stirmi's. They are leggier than stirmis and blondis.

Habitat: Tropical regions of Venezuela where they create deep burrows.

Husbandry Notes:

Enclosure: 8x8x8

Sex: Undetermined

Life stage: Juvenile

Size: Approximately 3.25 in

Growth: Steady, has molted twice

Disposition: Generally stays near their burrow and a bit skittish.

Eating habits: Typically an aggressive eater

Misc: Typically always in the same place but has been more mobile lately. Very leggy.