Xenesthis immanis, the Colombian lesser black tarantula,Common Names of Arachnids, American Arachnological Society (2003) is a terrestrial bird spider (tarantula) originating from Colombia. 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, another microhylid.
