Another stripe on the tiger makes no difference? Unexpected diversity in the widespread tiger tarantula Davus pentaloris (Araneae: Theraphosidae: Theraphosinae)

Abstract

Abstract Integrative taxonomy is relevant for the discovery and delimitation of cryptic species by incorporating different sources of evidence to construct rigorous species hypotheses. The genus Davus was recently revised and it was found that Davus pentaloris presents high morphological variation across its widespread distribution. However, tarantulas usually present low dispersal capabilities that occasionally result in local endemism. In order to evaluate species boundaries within this taxon, we examine the morphological variation and, additionally, employ four strategies based on mtDNA data (COI): two distance-based [automatic barcode gap discovery (ABGD) and Neighbor-Joining (NJ)] and two tree-based methods [general mixed Yule coalescent (GMYC) and Bayesian Poisson tree process (bPTP)]. Available morphological evidence recovers 13 putative morphospecies, but the different methods based on molecular data recover a variable number of candidate species (16–18). Based on the congruence across all analyses and the available morphological data, we recognize 13 clearly diagnosable species, 12 of them new to science. We conclude that the underestimation of the diversity in D. pentaloris was mainly caused by deficient practices in taxonomy, rather than by the presence of cryptic diversity. Although COI is a functional barcoding marker and it gives reliable results in our study, we recommend combining multiple sources of evidence and strategies to construct better species delimitation hypotheses.