Abnormal pelage color in mantled howler monkey (Alouatta palliata mexicana) in Veracruz, México

Leucism is a total or partial depigmentation of the coat; in contrast, albinism is the total loss of pigments throughout the body; the abnormal conditions of pigment deficiency are usually due to the expression of recessive genes.  Expedition ad libitum was carried out in the Ejido Alvaro Obregon, on the southwest of Nuevo Canton, Uxpanapa municipality, Veracruz on December, 2019.  We present the first record of abnormal pelage colour (maybe leucismo or albinism) in mantled howler monkey (Alouatta palliata mexicana), observed in a wild troop in the Uxpanapa Valley region, Veracruz, Mexico.  The coloration of the oral mucosa and the eyelid show no pigmentation and may be the result of the expression of recessive genes in the individual, therefore, conducting more in-depth studies on the expression of recessive genes would broaden the understanding of the phenomenon.