摘要：As a general rule, spiders exhibit sexual dimorphism and their populations may differ in size according to season duration and resourceavailability. However, few studies have focused on dimorphism in tarantulas. Mexican redrump tarantulas, Brachypelma vagans, listed in CITES,have an exceptionally wide distribution. Surprisingly, there are no studies on the possible relationship between the abundance of tarantulas perpopulation and the geographical areas where they are present, or on how the distribution pattern of this spider may affect individual morphologicalcharacteristics. Furthermore, there are no studies on sexual dimorphism within the genus Brachypelma. The aim of the study is to determine theexistence of sexual and geographical dimorphism in populations of B. vagans. It was observed that the abundance of spiders per population mayvary according to the geographical areas where they were recorded. In six localities in southern Mexico, we recorded morphological data on adulttarantulas. Sexual dimorphism was clearly observed at the site that presented numerous spiders characterized by much smaller females. Since theresults of this study demonstrate differences in tarantula number of individuals per locality in southern Mexico, they make an important contributionto the conservation of this species.
