Aberrant colourations in wild snakes: case study in Neotropical taxa and a review of terminology

CLAUDIO BORTEIRO; FABRICIO HIROUKI ODA; DARIO CARDOZO; FRANCISCO KOLENC; IGNACIO ETCHANDY; IRASEMA BISAIZ; CARLOS PRIGIONI; DIEGO BALDO

Salamandra

Deutsche Gesellschaft für Herpetologie und Terrarienkunde

Lugar: Manhein; Año: 2021 vol. 57 p. 124 - 138

0036?3375

The criteria used by previous authors to define colour aberrancies of snakes, particularly albinism, are varied and terms have widely been used ambiguously. The aim of this work was to review genetically based aberrant colour morphs of wild Neotropical snakes and associated terminology. We compiled a total of 115 cases of conspicuous defective expressions of pigmentations in snakes, including melanin (black/brown colour), xanthins (yellow), and erythrins (red), which in- volved 47 species of Aniliidae, Boidae, Colubridae, Elapidae, Leptotyphlopidae, Typhlopidae, and Viperidae. Most of them were hypopigmented conditions, mainly amelanism, but also anerythrism, axanthism, hypomelanism, leucism, piebald- ism, and albinism (total absence of pigments). Hyperpigmented aberrancies were mostly melanism and xanthism, plus a few instances of erythrism. No associations with diurnality and fossorial behaviour were observed, neither for blanched nor hyperpigmented aberrancies. A discussion of the terms most commonly used for wild snakes is provided, with an ac- count of cases of aberrant colourations in other South American reptiles. Finally, we propose a simple classification frame- work of wild snake colour aberrancies based on predominant dorsal colour and eye pigmentation for the adoption of a standardized terminology, which may be applicable to other squamates and chelonians. We advocate the use of a more ac- curate terminology in the scientific literature that would avoid the use of confusing terms like ?partial albinism?.