Molecular and morphological systematics of hypogean schizomids (Schizomida:Hubbardiidae) in semiarid Australia

Abstract

We used molecular and morphological techniques to study troglobitic schizomids inhabiting a variety of subterranean landforms in semiarid Western Australia. The study was designed to explore the taxonomic and phylogenetic status of newly discovered populations of subterranean schizomids. Molecular sequences of the mitochondrial DNA (mtDNA) cytochrome oxidase subunit 1 (COI) and small subunit rRNA (12S) were obtained from a total of 73 schizomid specimens. Populations sampled from boreholes within mesa landforms in the Robe Valley were highly genetically distinct from species of Draculoides Harvey, 1992 found elsewhere in the Pilbara (Cape Range and Barrow Island). Pronounced genetic structuring was also evident at a fine spatial scale within the Robe Valley, with populations from each of the mesas examined exhibiting unique and highly divergent mtDNA lineages. These molecular data were generally supported by small but significant morphological features, usually in the secondary male structures, but some species were represented only by female specimens that possessed more conservative morphologies. The molecular data defined two major in-group clades, which were supported by morphological differences. One clade was widespread and included the type species of Draculoides, D. vinei (Harvey), along with D. bramstokeri Harvey & Humphreys, D. brooksi Harvey, D. julianneae Harvey, D. mesozeirus, sp. nov. and D. neoanthropus, sp. nov. The second clade was restricted to the Robe Valley and deemed to represent a new genus, Paradraculoides, which included four new species P. anachoretus, sp. nov., P. bythius, sp. nov., P. gnophicola, sp. nov. and P. kryptus, sp. nov. (type species).