Use of geometric morphometrics to distinguish trapdoor spider morphotypes (Mygalomorphae: Anamidae: Proshermacha): a useful tool for mygalomorph taxonomy
Abstract
Taxonomic studies have evolved greatly since their early stages and new techniques have been incorporated to improve species descriptions. Those involving the comparison of traits, either quantitatively or qualitatively, can be difficult because the identification of a species must rely on the experience of the observer and errors can occur when cryptic species are involved. Molecular methods have been used to fill these gaps, but morphological methods are still needed to match the recognized molecular species with an adequate taxonomic description. Focusing on the trapdoor spider genus Proshermacha Simon, 1908, we provide a case study using Geometric Morphometrics (GM) techniques to identify morphological divergence between species found in the south-western Australia region. We used GM to identify morphological divergence from museum-preserved specimens by examining shape variation of sexual characters from 39 male specimens from five different localities on a single mountain range. Variation in the shape of both the palpal bulb and tibia provided strong evidence to distinguish two morphotypes, while metatarsus shape showed fewer between-locality differences. Our results illustrate the utility of GM methods, when applied to a few taxonomically-informative structures, as a quantitative species delimitation tool for taxonomic studies.
Kevin O. Sagastume-Espinoza, Leigh W. Simmons, Mark S. Harvey "Use of geometric morphometrics to distinguish trapdoor spider morphotypes (Mygalomorphae: Anamidae: Proshermacha): a useful tool for mygalomorph taxonomy," The Journal of Arachnology, 52(1), 31-40, (8 April 2024)
