The black pigment mutation of the Mongolian gerbil is inherited as an autosomal recessive and is not linked to the pigment mutation spotted (Sp). Black gerbils have deep glossy black coats, yellow perineal hairs, and small white patches under the chin and across the front feet. The black hairs are pigmented entirely with eumelanin including numerous cortical granules. The similarities between the black gerbil mutant and various black pigment mutations in mice area discussed.