Melanism
![Melanistic Guinea pigs are relatively rare, and considered especially effective in ritual use by Andean curanderos.[1]](/uploads/202501/19/Cavia_porcellus-Licorice4345.jpg)
Melanism is a development of the dark-colored pigment melanin in the skin or its appendages and is the opposite of albinism. Historically, it was also the medical term for black jaundice.
The word melanism is derived from the Greek:μελανός ("black pigment").