''Xenesthis immanis'', the Colombian lesser black tarantula, is a terrestrial bird spider (

tarantula Tarantulas comprise a group of large and often hairy spiders of the family Theraphosidae. , 1,040 species have been identified, with 156 genera. The term "tarantula" is usually used to describe members of the family Theraphosidae, although ...

) originating from

Colombia Colombia (, ; ), officially the Republic of Colombia, is a country in South America with insular regions in North America—near Nicaragua's Caribbean coast—as well as in the Pacific Ocean. The Colombian mainland is bordered by the Car ...

. It is a relatively large spider with a body length reaching 6–7 cm and a length width reaching 19-22 cm. It frequently displays a commensal or mutualistic relationship with the microhylid frog '' Chiasmocleis ventrimaculata''.Reginald B. Cocroft and Keith Hambler
"Observations on a Commensal Relationship of the Microhylid Frog ''Chiasmocleis ventrimaculata'' and the Burrowing Theraphosid Spider ''Xenesthis immanis'' in Southeastern Peru"
''Biotropica'' Vol. 21 No. 1 (1989) The relationship described is one where the spider may protect the frog and its eggs from predators while the frog protects the spider's eggs from ants. It has also been observed closely associating with ''

Hamptophryne boliviana ''Hamptophryne boliviana'', also known as the Bolivian bleating frog or Amazon sheep frog, is a species of frogs in the family Microhylidae. It is found in the northern and western sides of the Amazon basin in Bolivia, Brazil, Colombia, Ecuador, ...

'', another microhylid.

References

Theraphosidae Arthropods of Colombia Spiders of South America {{Theraphosidae-stub