''Pthirus gorillae'' or gorilla louse is a species of

parasitic Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson ha ...

sucking louse that afflicts

gorilla Gorillas are herbivorous, predominantly ground-dwelling great apes that inhabit the tropical forests of equatorial Africa. The genus ''Gorilla'' is divided into two species: the eastern gorilla and the western gorilla, and either four or fi ...

s. It is found in the African continent, specifically in Rwanda and

Democratic Republic of the Congo The Democratic Republic of the Congo (french: République démocratique du Congo (RDC), colloquially "La RDC" ), informally Congo-Kinshasa, DR Congo, the DRC, the DROC, or the Congo, and formerly and also colloquially Zaire, is a country in ...

. ''P. gorillae'' and ''P. pubis'' (the

crab louse The crab louse or pubic louse (''Pthirus pubis'') is an insect that is an obligate ectoparasite of humans, feeding exclusively on blood. The crab louse usually is found in the person's pubic hair. Although the louse cannot jump, it can also liv ...

) are the only known species that belong to the

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

'' Pthirus'', often incorrectly spelled as ''Phthirus'' (the Greek word for louse is ''phthir''). It is suggested that it is transmitted among its

hosts A host is a person responsible for guests at an event or for providing hospitality during it. Host may also refer to: Places *Host, Pennsylvania, a village in Berks County People *Jim Host (born 1937), American businessman *Michel Host ( ...

by social grooming, shared bedding and sexual contact. All species of sucking lice feed on blood. They live in close association with their hosts and complete their entire life cycle on the host. ''Pthirus gorillae'' infests the same parts of the bodies of gorillas as ''Pthirus pubis'' does in humans, but since the gorilla is hairier, the lice tend to range over the whole body. The two also resemble each other with the exception that ''Pthirus gorillae'' has large eyes that are placed on large lateral protuberances. A short and broad sucking louse, it is about 2.20 mm long with sprawling legs and not more than 20 small abdominal

seta In biology, setae (singular seta ; from the Latin word for " bristle") are any of a number of different bristle- or hair-like structures on living organisms. Animal setae Protostomes Annelid setae are stiff bristles present on the body. ...

e. It was first identified from specimens of mountain gorillas in 1927 by

Henry Ellsworth Ewing Henry Ellsworth Ewing (11 February 1883 – 5 January 1951) was an American arachnologist. He worked at several universities, but spent most of his career at the Bureau of Entomology and Plant Quarantine. Ewing was considered an authority on arachn ...

during a game-hunting trip in what is now the Democratic Republic of the Congo.

Molecular phylogenetics Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to ...

suggest that ''P. gorillae'' jumped from gorillas to early humans 3.3 million years ago and diverged into the present-day pubic louse. Researchers theorize that humans acquired the parasite while butchering or scavenging on gorilla carcasses, or sleeping in the abandoned sleeping nests of gorillas. Several lice of the species were found during a

necropsy An autopsy (post-mortem examination, obduction, necropsy, or autopsia cadaverum) is a surgical procedure that consists of a thorough examination of a corpse by dissection to determine the cause, mode, and manner of death or to evaluate any di ...

in the stomach of a female gorilla from

Bwindi Impenetrable National Park The Bwindi Impenetrable National Park (BINP) is in southwestern Uganda. The park is part of the Bwindi Impenetrable Forest and is situated along the Democratic Republic of the Congo (DRC) border next to the Virunga National Park and on the edge o ...

; she had presumably been grooming before she died. The conservation status of this species is unknown. Since its host species is critically endagered, it is likely that this species is endangered too.

References

External links

Apes, lice and prehistory
by Robin A Weiss
Genetic Analysis of Lice Supports Direct Contact between Modern and Archaic Humans
by David L. Reed et al. {{Taxonbar, from=Q7257035 Lice Insects of Africa Insects described in 1927 Parasites of primates