melanistic
adjective biology specialized uk/ˌmel.əˈnɪs.tɪk/ us/ˌmel.əˈnɪs.tɪk/
黑变的，黑素沉着的
having very dark skin or hair because it contains a higher than normal level of the pigment (= substance that gives colour) known as melanin
Black panthers are a melanistic variant of leopards. 黑豹是美洲豹的黑色变种。
Compare: albino