Here, we present the results of the first phylogenetic and biogeographical analysis of the marine littoral Adota on the Pacific coasts of the Northern Hemisphere. The biogeographic patterns were compared with those of different lineages of aleocharine beetles with different microhabitats. Reconstructions of the ancestral areas suggest that the common ancestor of Adota occurred widely along the East Asian coasts. Both dispersal and vicariance were important in shaping the current distribution. (Image credit: Jong-Keun Jung and Kee-Jeong Ahn.)

The maternal mitochondrial genomes of Unio szechenyii, Cuneopsis kiangsiensis, Middendorffinaia mongolica and Pseudocuneopsis wuana are sequenced. The validity of Unio szechenyii, previously considered a synonym of Cuneopsis heudei, is supported by the integration of conchometry, soft-body anatomy and molecular evidence, and a recombination as Cuneopsis szechenyii comb. nov. is proposed. The intrageneric relationships within the genera Cuneopsis and Pseudocuneopsis are elucidated based on the mitochondrial phylogenomics. Middendorffinaia mongolica, a new record for China, is proposed for transfer from the tribe Middendorffinaiini to the tribe Unionini and classification under the subtribe Middendorffinaiina stat. rev. (Image credit: Ruiwen Wu.)

In this study we report two new stygomorphic amphipods, Palearcticarellus hyperboreus sp. nov. and Pseudocrangonyx elgygytgynicus sp. nov., from Lake El’gygytgyn in north-eastern Siberia. Molecular phylogenetic analyses confirm their affinity to Crangonyctidae and Pseudocrangonyctidae, respectively, and reveal that speciation preceded Pleistocene glaciations. Although adapted to subterranean life, these species are found exclusively in surface waters, highlighting Lake El’gygytgyn as a high latitude refugium for ancient pre-glacial fauna and expanding the known distribution of stygomorphic amphipods. (Image credit: Denis Copilaş-Ciocianu and Dmitry Sidorov.)

The epigean and subterranean spider genus Cybaeus is highly species rich in the Japanese Archipelago. The Japanese Cybaeus spiders are classified into ~100 species, but their phylogeny is unclear. We conducted molecular phylogenetic analyses and divergence time estimation based on 73 species and demonstrated that several Cybaeus species should be classified into other genera. Divergence dating suggested that the opening of the Sea of Japan c. 20 million years ago may have promoted diversification and speciation of Japanese cybaeids. (Image credit: Yoh Ihara and Takafumi Nakano.)

Taxonomic identification of spider species from morphological structures has limitations in cases of closely related species or intraspecific variability. We investigate the utility of genetic barcoding with the mitochondrial marker cytochrome c oxidase I (COI) in ghost spiders of the subfamily Amaurobioidinae. Most discrepancies between DNA barcoding and morphological identification are explained by low geographic sampling or by geographically structured lineages. In addition, we show that the marker COI is phylogenetically informative for deeper nodes in the tree. (Image credit: Martín Ramírez.)

We sampled ~75% of Apatelodidae species from all valid genera and combined morphological and molecular data to test monophyly of its genera. Our findings demonstrate that most Apatelodidae genera, as currently understood, are not monophyletic and revealed that groups of species with similar characters may constitute valid genera. We propose a new genus-level classification for Apatelodidae and include data on its natural history and geographical distribution. (Image credit: Guilherme Fischer.)

Boniniidae is a family of marine polyclad flatworms harbouring nine named species distributed worldwide. We describe a new boniniid species, Boninia panamensis from the Pacific coasts of Panama based on morphological and molecular data. We also report Boninia cf. uru from Hawai’i and Boninia oaxaquensis from Panama along with morphological descriptions. In addition, we discuss synapomorphic traits and possible speciation pathways in this genus based on the reconstructed molecular phylogenetic results using 18S rDNA, 28S rDNA, 16S rDNA and COI. (Photograph by Marco Curini-Galletti.)

Pollen beetles of the genus Teucriogethes (Meligethinae) are strictly associated with the flowers of germanders, Teucrium (Lamiaceae). We analysed and described a new species, Teucriogethes huangae, recently discovered in Central China, associated as larvae with a strongly isolated member of Teucrium, T. ornatum. The new species occupies an isolated position inside Teucriogethes revealed by combining both morphological and molecular analyses, as well as bionomical data. This paper provides a significant contribution to many important evolutionary and taxonomical aspects of Teucriogethes. (Image credit: Meike Liu, Simone Sabatelli and Paolo Audisio.)

Morphology is not always a good indicator of biological diversity, aswe illustrate in Asian species classified under Cercyon, a genus of terrestrial water scavenger beetles. We describe Asiacyon gen. nov., which is strongly supported by DNA data, has limited distribution and unique habitat preferences, yet it highly resembles other unrelated ʻCercyonʼ. The species diversity of this lineage was under-estimated: we describe 11 new species from China. We argue that ‘Cercyon’ should be divided into DNA-based natural genera despite their morphological similarity. (Image credit: Martin Fikáček.)

Three new cave-dwelling aeglid species are described from the Alto Ribeira karst region, south-eastern Brazil using morphological and molecular (16S rDNA) data. Comparison of molecular sequences from several subterranean and epigean species in the region reveal two dispersal events involving epigean ancestors that resulted in two distinct subclades of extant cave-dwelling species. Adaptation to subterranean habitats among the cave-dwelling species developed independently within each subclade resulting in each having an exclusive group of both stygobitic and stygophilic species. (Image credit: Sérgio Bueno.)

Tribal relationships within the braconid subfamily Rogadinae are reconstructed based on nuclear UCE data and extensive taxon sampling. Our fully supported estimate of phylogeny and the morphological evidence led us to erect a new rogadine tribe, Gondwanocentrini Shimbori & Zaldívar-Riverón trib. nov. Facitorini was also confirmed as a separate rogadine tribe. Our updated classification expands the number of tribes and genera within Rogadinae to 8 and 66 respectively. (Image credit: Eduardo M. Shimbori.)

Species of the genus Eubranchus Forbes, 1838 are common in boreal benthic ecosystems. Recent studies suggest the trans-Arctic Eubranchus rupium (Møller, 1842) is a species complex. This paper conducts an integrative taxonomic study of Eubranchus rupium and related species, confirming its amphiboreal distribution. The divergence of the species complex is estimated from the late Miocene or the Miocene–Pliocene boundary to the late Pliocene with the north-western Pacific as the probable ancestral region, followed by dispersal and allopatric speciation. (Image credit: Darya Grishina.)