Last week, I shared this specimen with you:
![Anoplura with broad legs and thick antennae.](https://c2.staticflickr.com/6/5820/21904810790_d0f778cafc.jpg)
It’s a gorilla louse, Pthirus gorillae (Ewing, 1927) (Anoplura: Pthiridae), a species of pubic louse. Morphology and molecular data has shown that Pediculus and Pthirus are sister taxa (Reed et al 2007). Gorillas are host to pubic (Pthirus) lice, but not head (Pediculus) lice, while humans are host to both, and chimpanzees are host to only head lice.
![Biological drawing of a gorilla.](https://c2.staticflickr.com/8/7224/6901565782_86b3845276.jpg)
The divergence of Pthirus pubis and Pthirus gorillae is not entirely understood; the split may have occurred before the split between humans and gorillas or much more recently. Regardless, there was likely a host switch at some point from gorillas to humans, resulting in crabs (pubic lice) for humans. One hypothesis on the host switch is that humans were feasting on dead gorillas that were harboring lice, resulting in their transfer to another living host in order to survive (Morand et al 2015). This is definitely something to consider when scavenging for bush meat.