Morfometría geométrica en cinco especies de Buthidae y Scorpionidae (Arachnida: Scorpiones) de Venezuela

The Venezuelan scorpionfauna comprises 17 genera and 202 species. In some taxa the taxonomy is unclear, and additional studies that contribute to the knowledge about taxonomic identity and relationships are necessary. Geometric morphometrics is a tool that has been used as support to the systematics in different organisms. The goal was to analize the isometric size and conformation in five scorpions species. We photographed 266 individuals of four speceis of Buthidae: Centruroides testaceus, Rhopalurus laticauda, Tityus clathratus and T. discrepans, and one species of Scorpionidae: Tarsoporosus yustizi. Coordinate (x,y) configurations from landmarks and semilandmarks were registered in five structures. The results showed the complete separation in Buthidae species through dorsal trichobotria on patella pedipalp; and a consistent separation at family level in the remaining structures. The thin plate spline showed the sternum horizontal compression in the Buthidae species and the vertical compression in Scorpionidae. Similarity in coxae, chelae and caparace between R. laticauda and C. testaceus was determined. The trichobotria disposition and the sternum conformation allows to discriminate T. discrepans and T. clathratus.