Abstract

CAICEDO-PORTILLA, JOSÉ RANCES. Sexual dimorphism and geographic variation of the blind snake Typhlops reticulatus (Scolecophidia: Typhlopidae) and distribution of species of the genus in Colombia. Caldasia [online]. 2011, vol.33, n.1, pp.221-234. ISSN 0366-5232.

Typhlops has a pantropical distribution. Due to their fossorial habits, these snakes are poorly represented in collections, making it difficult to take taxonomic data. I verified all Colombian collections and registered 56 specimens. Only three species of Typhlops are known for Colombia: Typhlops brongersmianus, T. minuisquamus, and T. reticulatus. The geographic distribution of T. brongersmianus and T. minuisquamus are extended to the eastern flank of the Oriental Cordillera. Additional records of T. reticulatus are given. The meristics and quantitative ranges are in agreement with literature data for T. brongersmianus. Typhlops minuisquamus has a higher number of total dorsal scales and variation in the dorsal scales formulae than previously reported as in T. reticulatus. I found significant intraspecific differences in the total body length, in which females are greater than males, and a cis- and trans-Andean difference in dorsal scale counts. Despite exhibiting a distinct geographical variation, it is not possible to argue that the geographically separate populations are independent evolutionary units. Future morphological studies including more specimens across the species distribution range are necessary.

Keywords : Typhlops; Blind-snakes; Colombia; Sexual dimorphism; Geographic variation.

        · abstract in Spanish     · text in Spanish     · Spanish ( pdf )