Integrative Taxonomy Approach Reveals Cryptic Diversity within the Phoretic Pseudoscorpion Genus Lamprochernes (Pseudoscorpiones: Chernetidae)

Abstract

Pseudoscorpions represent an ancient, but homogeneous group of arachnids. The genus Lamprochernes comprises several morphologically similar species with wide and overlapping distributions. We implemented an integrative approach combining molecular barcoding (cox1), with cytogenetic and morphological analyses in order to assess species boundaries in European Lamprochernes populations. The results suggest ancient origins of Lamprochernes species accompanied by morphological stasis within the genus. Our integrative approach delimited three nominal Lamprochernes species and one cryptic lineage Lamprochernes abditus sp. nov. Despite its Oligocene origin, L. abditus sp. nov. can be distinguished from its closest relative only by molecular and cytogenetic differences, or alternatively, by a complex multivariate morphometric analysis involving other Lamprochernes species. The population structure and common haplotype sharing across geographically distant populations in most Lamprochernes species suggest that a phoretic manner of dispersal is efficient in this group.

Species delimitation with limited sampling: An example from rare trapdoor spider genus Cyclocosmia (Mygalomorphae, Halonoproctidae)

“…Ideally, other sources of evidence would be taken into account and the validation would be performed in an integrative framework (Carstens et al., 2013; Edwards & Knowles, 2014). Cytogenetics data (Řezáč et al., 2018; Štundlová et al., 2019), geometric morphometry (Christophoryová et al., 2023; Korba et al., 2022) and species distribution modelling (Newton et al., 2020; Stockman & Bond, 2007) were used for delineating taxa boundaries in morphologically homogeneous arachnids. Unfortunately, our final delimitation hypothesis does not allow statistical validation by the latter two methods, because the majority of the delimited taxa is composed of few individuals and singletons.…”

“…Cytogenetics data (Řezáč et al, 2018; Štundlová et al, 2019), geometric morphometry (Christophoryová et al, 2023;Korba et al, 2022) and species distribution modelling (Newton et al, 2020;Stockman & Bond, 2007) (Arnedo & Ferrández, 2007) and the Chinese primitively segmented trapdoor spider Ganthela (Xu et al, 2018), but they also affect species distributions in vertebrates (Barrow et al, 2018;Soltis et al, 2006). The rivers play a particularly important role in the Southern Coastal Plain biodiversity hotspot, their changing course and local flooding created a system of patchy habitats that helped promote diversification in the region (Noss et al, 2015).…”

“…Whole specimen collection is thus often inevitable. For example, dissection of specific body parts or internal structures may be necessary for correct identification (Araujo et al., 2020; Christophoryová et al., 2023; Homma et al., 2020; Kergoat et al., 2015), sufficient DNA yield requires whole body extraction in small organisms or a reference voucher is needed (Català et al., 2021; Johnson et al., 2018). In case of unavoidable whole specimen sampling, the necessity to prevent the overexploitation of the species' natural populations may thus further restrict the number of collected individuals (Hedin, 2015; Jacobs et al., 2018).…”

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

“…Principally, three processes may lead to morphological crypsis [14]: (i) recent divergence, i.e., time since speciation was too short to allow morphological differentiation, (ii) morphological convergence, i.e., morphological similarity evolved independently among distantly related taxa in response to similar selection pressures, or (iii) morphological stasis, i.e., niche evolution and hence morphological differentiation across descendant species was constrained by selection (also known as the phylogenetic niche conservatism hypothesis). Christophoryová et al [15] estimated that cryptic Lamprochernes species diverged during the Oligocene era (approximately 31 Ma) and thus concluded that morphological stasis was the effective course. Morphological uniformity can challenge species delineation even if evolutionary distances are large, and traditional species diagnoses based on morphological characters may fail in such groups [16].…”

“…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.…”