Molecular analyses of pseudoscorpions in a subterranean biodiversity hotspot reveal cryptic diversity and microendemism

Abstract

Nested within the Mediterranean biodiversity hotspot, the Dinaric Karst of the western Balkans is one of the world’s most heterogeneous subterranean ecosystems and renowned for its highly diverse and mostly endemic fauna. The evolutionary processes leading to both endemism and diversity remain insufficiently understood, and large-scale analyses on taxa that are abundant in both subterranean and surface habitats remain infrequent. Here, we provide the first comprehensive molecular study on Croatian pseudoscorpions, a lineage of arachnids that is common and diverse in both habitats. Phylogenetic reconstructions using 499 COI sequences derived from 128 morphospecies collected across the Dinaric Karst show that: (i) occurrence in karstic microhabitats boosters speciation and endemism in the most diverse genera Chthonius C.L. Koch, 1843 (37 morphospecies) and Neobisium Chamberlin, 1930 (34 morphospecies), (ii) evidence for ongoing diversification is found in many species and species complexes through low optimal thresholds (OTs) and species delineation analyses, and (iii) landscape features, such as mountain ranges, correlate with patterns of genetic diversity in the diverse genus Neobisium. We present two synonymies: Protoneobisium Ćurčić, 1988 = Neobisium, syn. nov., and Archaeoroncus Ćurčić and Rađa, 2012 = Roncus L. Koch, 1873, syn. nov. Overall, our study suggests that karstic microhabitats promote diversification in soil- and cave-dwelling arthropods at all taxonomic levels, but also provide important refugia for invertebrates in past and present periods of environmental change.

A preliminary phylogeny for the pseudoscorpion family Garypinidae (Pseudoscorpiones: Garypinoidea), with new taxa and remarks on the Australasian fauna

“…Fragments of one mitochondrial and two nuclear genes were sequenced using standard Sanger methodology for this study and these sequences have proven to be useful in reconstructing pseudoscorpion phylogeny in a range of different taxa (Murienne et al 2008;Harvey et al 2015Harvey et al , 2016aHarvey et al , 2016bHarvey et al , 2020Harms et al 2019;Johnson et al 2022;Hlebec et al 2023). The present study included fragments of the cytochrome c oxidase subunit I (COI), 18S ribosomal RNA (18S) and 28S ribosomal RNA (28S).…”

The Subterranean Species of the Vjetrenica Cave System in Bosnia and Herzegovina

“…Only two species of Verhoeffiella are listed for the whole system [12] (Figure 6D), although more species belonging to different genera and even families are known from it (Lukić M., personal communication). Finally, numbers might further increase by identification of morphologically cryptic species, which are repeatedly identified among specialized subterranean taxa, including Dinaric collembolans [101][102][103].…”

And Yet They Differ: Reconsiderations of Diversity within Dactylochelifer latreillii (Arachnida: Pseudoscorpiones)

“…There is growing evidence that even in central Europe, a region with a long tradition of faunistic and taxonomic research [17], the true species diversity of pseudoscorpions is not even roughly known. Studies involving DNA barcoding have demonstrated that currently accepted species often constitute complexes of cryptic species [15,[18][19][20]. This was most obvious in non-vagile, soil-dwelling representatives (Chthoniidae, Neobisiidae), with Neobisium carcinoides (Hermann, 1804) being the most prominent example.…”