Iridopelma

Iridopelma is a small genus of New World arboreal tarantulas endemic to Brazil. It was erected in 1901 by British arachnologist Reginald Innes Pocock, who separated these delicate, tree-dwelling spiders from the catch-all “bird spider” groupings that dominated 19th-century taxonomy.

For much of the 20th century Iridopelma was poorly known, represented mainly by the type species Iridopelma hirsutum and a handful of scattered records from the Brazilian Atlantic rainforest. Additional names described earlier in broad genera such as Mygale and later moved into Iridopelma (for example I. leporina and I. plantaris) proved difficult to interpret and are now treated as nomina dubia (dubious names).

A major modern overhaul came with Rogério Bertani’s 2012 revision of the aviculariine tree tarantulas, which re-diagnosed Iridopelma based on detailed morphology and biogeography. In that work he clarified the limits of the genus, synonymized I. palmicola with I. hirsutum, and described several new species, including I. katiae, I. marcoi, I. oliveirai and I. vanini from northeastern and central-western Brazil.

Today, Iridopelma comprises six recognized species, all Brazilian endemics occupying a mix of Atlantic rainforest and drier savanna-type habitats such as cerrado and caatinga. Ongoing field work on South American arboreal tarantulas continues to refine our understanding of this genus, but Iridopelma remains one of the more localized and rarely encountered groups in both nature and the hobby.

Required reading for this genus: https://zookeys.pensoft.net/articles.php?id=3211

Bertani 2012

Iridopelma sp. rosa (CF. Oliveirai)

• Common Name:

  • “Rosa Pink Toe” (also sold as “Ruby Bloom Pink Toe” / “Rosy Red Pink Toe”)

• Origin:

  • Northeastern Brazil (primarily Bahia) – Atlantic Forest fragments, cerrado savanna, and caatinga scrub

• Lifestyle:

  • Arboreal New World tarantula

  • Webby, retreat-building tree dweller that prefers vertical space and foliage

• Adult Size:

  • Small to medium arboreal species

  • Approx. 3.5–4.5" (9–11 cm) diagonal leg span for adult females

• Growth Rate:

  • Moderate to fast; slings put on size quickly with regular feeding and warm temps

• Temperament:

  • Very quick and agile, prone to sudden sprints and short jumps

  • Generally shy but can be defensive if cornered

  • Best for keepers with some arboreal experience

• Color & Appearance:

  • Slings/juveniles: rosy-red to wine-colored abdomen with darker legs and contrasting setae

  • Adult females: soft greenish carapace, darker legs with bright red or orange “toes,” and bold darker striping/banding on the abdomen

  • Overall look is a vivid, high-contrast “pinktoe-style” arboreal with a unique rosy/red theme

Species History

Iridopelma sp. “Rosa” is an arboreal New World tarantula from the Brazilian genus Iridopelma, a group of tree-dwelling spiders known from eastern Brazil.

In the hobby, “Rosa” is treated as a distinctive color locality closely allied to Iridopelma oliveirai. Because the original population behind “Rosa” has not yet been formally described, it’s usually labeled Iridopelma sp. “Rosa” (cf. oliveirai)—meaning it closely resembles I. oliveirai but may represent a separate, localized form.

This line entered the European and North American hobby relatively recently through small numbers of captive-bred spiders from Brazil. It quickly gained a following for its striking rosy-red abdominal tones in juveniles, with adult females maturing into soft greenish hues, red-tipped feet, and bold dark abdominal striping. These colors set “Rosa” apart from more typical pinktoe-type arboreals and have made it a sought-after choice for collectors who enjoy rare localities and more unusual arboreal species.

Natural Habitat

In the wild, Iridopelma species—including the “Rosa” form—are strictly arboreal and occur in northeastern Brazil, particularly in and around the state of Bahia.

They inhabit a mix of Atlantic Forest remnants and adjacent dry habitats such as cerrado savanna and caatinga scrub. In these patchwork landscapes, Iridopelma are typically found:

• High in trees and shrubs, where they spin silken retreats among leaves, bark crevices, and epiphytic plants.

• In warm, humid microclimates with good airflow, similar to the conditions of coastal and upland Brazilian forests.

• On vertical structures, which give them quick escape routes and access to abundant arboreal insect prey.

Because large areas of the Atlantic Forest have been reduced and fragmented, many Iridopelma populations now survive in small, isolated patches of native vegetation. This makes captive-bred “Rosa” animals an especially responsible option for keepers who want to enjoy this beautiful arboreal tarantula while minimizing pressure on wild habitats.

Our Specimen:

Given name: Acai

Sex: TBD

Life Stage: Sling

• New addition to our collection

Iridopelma hirsutum

• Common Name: Amazon Ribbed Tarantula / Amazon Ribbed Tree Spider

• Origin: Northeastern Brazil (lowland Atlantic forest and coastal regions)

• Lifestyle: Arboreal, webby; builds tube-like retreats by silking together leaves and hides in foliage and bark crevices

• Adult Size:

  • Females: around 4–4.5" (10–11.5 cm) diagonal leg span

  • Males: slightly smaller and more slender, around 3–3.5" (7.5–9 cm)

• Growth Rate: Moderate to fast for an arboreal New World species

• Temperament:

  • Skittish and very fast-moving

  • More likely to bolt than stand its ground, but can be defensive if cornered

  • Not recommended for handling

• Color & Appearance:

  • Slender, elegant arboreal build with long legs

  • Overall brown to tan base tones with contrasting darker markings

  • Fine, “hairy” appearance with iridescent setae giving a subtle sheen

  • Often shows lighter leg bands and a patterned abdomen, making it a striking display species in a planted arboreal setup

Species History

Iridopelma hirsutum was first described in 1901 by British arachnologist Reginald Innes Pocock, based on specimens collected in Pernambuco, Brazil. When Pocock described it, he also established the genus Iridopelma, making this species the benchmark for the group.

Over time, as taxonomists studied South American arboreal tarantulas in more detail, this species was moved around between different genera and picked up a few historical names (synonyms), including Avicularia hirsuta, Typhochlaena pococki, and Avicularia palmicola. All of these are now considered the same species: Iridopelma hirsutum.

Modern revisions of the Aviculariinae have clarified that I. hirsutum is a distinct Iridopelma species restricted to Brazil’s northeastern coastal region. Within the hobby it’s known as a quick, alert arboreal tarantula that can be a bit feisty but is generally hardy when kept correctly, and it’s increasingly offered under names like Amazon Ribbed Tarantula or Amazon Ribbed Tree Spider.

Natural Habitat

In the wild, Iridopelma hirsutum is found in lowland Atlantic forest and coastal habitats of northeastern Brazil, from roughly southern Bahia through Sergipe and nearby states. These areas are:

• Warm year-round

• Very humid

• Low elevation, typically below ~200 m

This is a strictly arboreal species. Rather than living on the ground, it spends its life in trees and shrubs, often making tube-like retreats by silking together two or more leaves. It can be found:

• In shrubs and small trees

• Between folded or rolled leaves

• Under loose bark or in trunk crevices

The region’s climate is tropical, with daytime temperatures commonly in the mid-20s°C (high-70s to low-80s°F) and high humidity most of the year, supported by frequent rainfall and only a mild dry season. Dense vegetation provides cover, climbing structure, and ambush points, while the spider’s speed and agility help it navigate the canopy and avoid predators.

Our Specimen:

Given name: TBD

Sex: TBD

Life Stage: Sling

• New addition to our collection