Not the same: phylogenetic relationships and ecological niche comparisons between two different forms of Aglaoctenus lagotis from Argentina and Uruguay

Abstract

Species are the fundamental category and the key to formulate conservation efforts. DNA and ecological niche modeling have become valuable tools for species delimitation. Wolf spiders include few web-living species, such as Aglaoctenus lagotis (Holmberg, 1876), a priority species for conservation in Uruguay. Behavioral and body coloration patterns of this species have allowed us to distinguish two groups (forms I and II). Here, we combine information from gene trees and multispecies coalescent analyses on mitochondrial (cox1, 12S, 16S + L1 + nad1) and nuclear (intron tif5A) DNA sequences, as well as from ecological niches comparisons, in order to clarify their taxonomic identity. We worked with localities in Uruguay and Argentina, including sympatric and allopatric areas. Gene trees were inferred with Maximum Likelihood, Bayesian, and statistical parsimony analyses. Molecular species delimitation analyses were conducted, and the species tree and divergence times were co-estimated. Characterization and comparison of the climatic requirements of both forms throughout annual and sexual periods were analyzed. Species delimitation and species tree analyses recovered three main lineages (Form I, Form IIa, and Form IIb). Form I is restricted to Uruguay and is closely related and sympatric with Form IIa. Form IIb is located in Argentina and in the Uruguayan west coast, generating a sympatric area of the three forms. Regarding to the sexual climatic niche, the three main lineages differ and do not overlap. Our results support the existence of more than one lineage within what is nowadays Aglaoctenus lagotis. Possible evolving processes explaining this scenario and the conservation consequences are discussed.