Which tamarin species is known for its white 'mustache'?

The tamarin known for its long white mustache is the emperor tamarin, Saguinus imperator.

This small New World monkey has predominantly gray fur, black hands and feet, and a brown tail. Its most striking feature is the white facial hair that extends outward from the muzzle and can project beyond the shoulders, giving it a remarkably dignified appearance. The species was allegedly named for the beard’s resemblance to German Emperor Wilhelm II.

Emperor tamarins live in the southwestern Amazon Basin, including parts of Brazil, Peru, and Bolivia. They spend most of their time in rainforest trees, using sharp claws on their fingers and toes to cling to branches; the big toe is an exception and bears a nail rather than a claw.

Two subspecies are commonly recognized: the black-chinned emperor tamarin and the bearded emperor tamarin. The latter has an especially prominent white beard, while the black-chinned form has less noticeable chin hair. Cotton-top tamarins are also distinctive, but their white crest is on the head rather than around the mouth.