Megaphobema

Megaphobema is a small New World tarantula genus first described by British arachnologist Reginald Innes Pocock in 1901, based on specimens of what we now call Megaphobema robustum from Colombia. Pocock separated Megaphobema from similar, bulky South American tarantulas (like Pamphobeteus) by its distinctive leg proportions: the third and fourth leg pairs are noticeably thicker and more powerful than the front legs, giving these spiders their “rear-heavy” look.

Over the 20th century, additional species were added from across the northern half of South America, including M. lakoi from Brazil (originally placed in Lasiodora), M. velvetosoma from Ecuador/Peru/Brazil, and M. teceae from Brazil. For many years hobbyists also knew Megaphobema mesomelas and M. peterklaasi as classic “redleg” Megaphobema species, but a 2023 taxonomic revision using morphology and new data moved both into a new genus, Abdomegaphobema.

Today, the genus Megaphobema is generally considered to contain four valid species:

• Megaphobema robustum – Colombian Giant Redleg (type species), from Colombia

• Megaphobema lakoi – from Brazil

• Megaphobema velvetosoma – from Ecuador, Peru and Brazil

• Megaphobema teceae – from Brazil

Across this history, Megaphobema has remained a niche but much-admired genus among keepers: large, heavily built terrestrial tarantulas from humid forest habitats, famous for their powerful back legs, tendency to kick urticating hairs, and impressive threat displays—yet often surprisingly secretive in captivity.

Megaphobema robustum

Common name: Colombian Giant Redleg, Colombian Giant Tarantula, Colombian Redleg

Origin: Primarily Colombia (especially the Bogotá region); also reported from neighboring areas of Brazil’s rainforest belt.

Lifestyle: New World terrestrial, opportunistic burrower; spends much of its time in or near a hide, usually emerging at night.

Adult size: Large; typically 6–8 in (15–20 cm) leg span in mature females.

Growth rate: Medium to medium–fast; faster than many classic “pet rock” terrestrials but not in the fastest-growing category.

Temperament: Generally shy and reclusive, often choosing to flee or hide; can be skittish and defensive when cornered, with a unique behavior of lunging or spinning while striking with the hind legs. Best viewed as a display animal, not for handling.

Color & appearance:

• Deep black carapace and abdomen, both cloaked in dense orange setae.

• Legs bright orange to red-orange with contrasting black femurs and dark “feet”, giving the classic “redleg” look.

• Heavy, powerful rear legs that are noticeably bulkier than the front pair and used in its characteristic defensive displays.

Species History

Megaphobema robustum was first described in 1875 by Austrian arachnologist Anton Ausserer, who originally placed it in the genus Lasiodora under the name Lasiodora robusta. At the time, South American tarantulas were poorly understood, and many large, ground-dwelling spiders from the region were lumped together in a handful of broad genera.

In 1901, British zoologist Reginald Innes Pocock created the genus Megaphobema and moved Ausserer’s species into it, giving us the name we use today: Megaphobema robustum. Pocock also designated it as the type species of the genus, meaning M. robustum is the reference point for defining what “Megaphobema” is. This change reflected a better understanding of its distinctive build, especially the powerful third and fourth leg pairs that set the genus apart from similar tarantulas such as Pamphobeteus.

Throughout the 20th century and into the 2000s, M. robustum has been re-examined in a series of taxonomic works that refined how males and females are diagnosed and clarified its relationships to closely related species. Recent revisions of Megaphobema and allied genera have shuffled some former “Megaphobema” species into a new genus (Abdomegaphobema), but M. robustum itself has remained stable as the iconic Colombian representative of the genus.

n the wild, Megaphobema robustum is native to humid tropical forests of Colombia, where it lives on or just below the forest floor, often near rotting logs. Its impressive size and fiery orange-and-black coloration, combined with its dramatic defensive spins and kicking motions with the hind legs, have made it a standout species in the tarantula hobby and a long-time favorite among keepers looking for a striking New World terrestrial.

Natural Habitat

In the wild, Megaphobema robustum lives in warm, humid lowland regions of Colombia, with records and hobby sources also pointing to populations in neighboring Brazil. These areas are tropical year-round, with heavy annual rainfall (around 2,500 mm) and consistently warm temperatures typically above 23°C.

Within this climate, M. robustum is a terrestrial forest-floor spider, spending most of its time in or near a burrow. It favors dense ground cover—leaf litter, roots, and rotting logs—where it can dig or adopt natural cavities and line them with silk for extra stability and humidity. Many specimens exported for the hobby are reported from lowland Colombian habitats such as the Los Llanos region, a hot, seasonally wet savanna with patches of gallery forest and thick vegetation that provide ideal cover.

Like many large tropical tarantulas, M. robustum is nocturnal and reclusive, rarely straying far from its burrow except to hunt. Ongoing deforestation and collection for the pet trade are cited as potential pressures on wild populations, making captive-bred animals the preferred, more sustainable choice.

Recommended reading: https://birdspiders.ch/megaphobema-robustum-nature/

Our Specimen:

Given name: Reese

Sex: TBD

Life stage: Sub-adult

• Our specimen burrows and rarely comes out.

• Has molted a couple of times and displays beautiful coloration.

• Has grown considerably and is now over 5 inches but we have not attempted to sex her.

https://birdspiders.ch/megaphobema-robustum-nature/