A team of arachnologists from universities in Uruguay and Colombia have discovered a new species of tarantula that features unique physiology unlike any other tarantula species. While researching spiders in the Sierra Nevada de Santa Maria region of Colombia, these spider experts noticed tarantulas with uncharacteristic rust-colored barbs covering their bodies. Upon closer inspection and analysis, the researchers then found that these spiders possess sexual organs unlike any other known tarantula species.
The team’s findings, published in ZooKeys, detail how the physiological traits of the newly-named genus Kankuamo make these spiders unique:
Males of Kankuamo gen. n. additionally differ by having a palpal bulb organ very divergent from all known species, with many conspicuous keels dispersed across the median tegulum to the tip, mostly with serrated edges.
Male spiders’ sex organs are in the form of bulbs on the ends of their front legs called palpal bulbs. These palpal bulbs are used to store and transmit sperm to female tarantulas. While many tarantula species have a layer of rough skin covering their palpal bulbs, the new Kankuamo spiders have serrations and barbs across the bulbs’ surface.
Female members of this tarantula genus have subsequently adapted their reproductive systems in response to the physiology of males:
Females differ by having spermathecae with a single notched receptacle, with two granulated lobes and several irregular sclerotized longitudinal striations.
The unique bristles and barbs on the Kankuamo tarantulas are used not only in reproduction, but also self-defense. These giant hairy spiders sport bristles that face in the same direction as their appendages, unlike all other known tarantula species whose barbs face the opposite direction. That means Kankuamo tarantulas can use their barbs in a direct attack as opposed to simply a defense mechanism.
The full name of the new tarantula species is Kankuamo marquezi, named after Colombian literary legend Gabriel García Márquez, who, while not sporting barbed genitalia, is the most important figure in Colombian literature and arguably all of Colombian art.