Discovery of a putative troglomorphic ant (Hymenoptera: Formicidae: Leptanillinae)

Despite their diversity and ubiquity across terrestrial ecosystems, the ants (Formicidae) are rare in cave environments. At present, only two described ant species are regarded as exhibiting a cave-adapted phenotype, i.e., troglomorphism. Here, we report workers of an undescribed species of Yavnella (Leptanillinae: Leptanillini) collected from the milieu souterrain superficiel (MSS) near salt caves in Fars Province, Iran. The body and appendages of this ant are bizarrely elongated, precluding the soil-dwelling behavior observed in other leptanilline ants. Therefore, this Yavnella sp. is confined to preexisting cavities and is troglomorphic, making it one of a very few examples of this syndrome among the ants. This species is recovered within Yavnella, a clade so far known only from males,by maximum-likelihood phylogenomic inference from ultra-conserved elements (UCEs). This conclusion corroborates the utility of multi-locus data for associating disparate forms in polymorphic organisms such as ants.