Morphological variation, polymorphism, and Taxonomy of the Atractus torquatus complex (Serpentes: Dipsadidae)

摘要

The taxonomic status of Atractus torquatus is revised on the basis of concordance between quantitative and qualitative analyses of morphological characters (meristic, morphometric, colour pattern, and hemipenis) throughout its geographical distribution. We propose the synonymy of Atractus davidhardi, A.janethae, and A. lucilae based on wide overlap of morphological characters (qualitative and quantitative). Despite some differences in the frequency of the number of suprala-bials, infralabials and maxillary teeth among A. torquatus populations, we find that these characters exhibit a high level of polymorphism and therefore cannot unambiguously diagnose Guiana Shield and Amazon Basin populations. Additionally, we discuss the polymorphism and geographical variation in A. torquatus and its appropriateness for hypotheses of landscape evolution in Amazonia.