Species Delimitation Analyses Research Articles

Molecular characterization uncovering a novel genus of tapering-filamentous cyanobacteria from Thailand: Phayaothrix lacustris gen. & sp. nov. (Nostocales, Cyanophyta)

In this study, novel Calothrix-like strains NUACC09 and NUACC10 were isolated from the surfaces of rocks in Phayao Lake, Thailand. Morphological, molecular and ecological comparisons were investigated to characterize the taxonomic status of these novel strains. Under the light microscope, morphological studies indicated that these two strains were morphologically similar to Calothrix but could be differentiated by production of a non-hyaline hair at the terminal end, a low degree of tapering, twisted or loop-forming filaments, a knotted growth form, intertwined trichomes and presenting more than one trichome within the single sheath. In the 16S rRNA and rbcLX gene phylogenetic tree analyses, our strains formed a monophyletic clade with former freshwater/terrestrial Calothrix-like taxa separating distantly from other Calothrix-like genera. Furthermore, low 16S rRNA gene sequence similarity (<94.9%) to the closely related genera and species delimitation analyses (PTP/bPTP, GMYC, ABGD and ASAP methods) indicated that this clade should be considered as a different cyanobacterial lineage. The phylogenetic tree and secondary structures (D1–D1′, V2, Box-B and V3 helix) based on 16S–23S rRNA ITS regions suggested that multiple species might be contained in this clade. Therefore, here, Phayaothrix was proposed as a novel cyanobacterial genus with Phayaothrix lacustris sp. nov. as the type species following the International Code of Nomenclature for algae, fungi and plants.

Of sea, rivers and symbiosis: Diversity, systematics, biogeography and evolution of the deeply diverging florideophycean order Hildenbrandiales (Rhodophyta)

The Hildenbrandiales, a typically saxicolous red algal order, is an early diverging florideophycean group with global significance in marine and freshwater ecosystems across diverse temperature zones. To comprehensively elucidate the diversity, phylogeny, biogeography, and evolution of this order, we conducted a thorough re-examination employing molecular data derived from nearly 700 specimens. Employing a species delimitation method, we identified Evolutionary Species Units (ESUs) within the Hildenbrandiales aiming to enhance our understanding of species diversity and generate the first time-calibrated tree and ancestral area reconstruction for this order. Mitochondrial cox1 and chloroplast rbcL markers were used to infer species boundaries, and subsequent phylogenetic reconstructions involved concatenated sequences of cox1, rbcL, and 18S rDNA. Time calibration of the resulting phylogenetic tree used a fossil record from a Triassic purportedly freshwater Hildenbrandia species and three secondary time points from the literature. Our species delimitation analysis revealed an astounding 97 distinct ESUs, quintupling the known diversity within this order. Our time-calibration analysis placed the origin of Hildenbrandiales (crown age) in the Ediacaran period, with freshwater species emerging as a monophyletic group during the later Permian to early Triassic. Phylogenetic reconstructions identified seven major clades, experiencing early diversification during the Silurian to Carboniferous period. Two major evolutionary events—colonization of freshwater habitats and obligate systemic symbiosis with a marine fungus—marked this order, leading to significant morphological alterations without a commensurate increase in species diversification. Despite the remarkable newly discovered diversity, the extant taxon diversity appears relatively constrained when viewed against an evolutionary timeline spanning over 800 million years. This limitation may stem from restricted geographic sampling or the prevalence of asexual reproduction. However, species richness estimation and rarefaction analyses suggest a substantially larger diversity yet to be uncovered—potentially four times greater. These findings drastically reshape our understanding of the deeply diverging florideophycean order Hildenbrandiales species diversity, and contribute valuable insights into this order evolutionary history and ecological adaptations. Supported by phylogenetic, ecological and morphological evidence, we established the genus Riverina gen. nov. to accommodate freshwater species of Hildenbrandiales, which form a monophyletic clade in our analyses. This marks the first step toward refining the taxonomy of the Hildenbrandiales order, a task demanding thorough revisions, notably the creation of several genera to address the polyphyletic status of Hildenbrandia. However, the limited diagnostic features pose a challenge, necessitating a fresh approach to defining genera. A potential solution lies in embracing a molecular systematic perspective, which can offer precise delineations of taxonomic boundaries.

A review of Nearctic Lathrobium (Coleoptera, Staphylinidae), with revision and descriptions of new flightless species from the mountains of the southeastern U.S.

Species of the genus Lathrobium Gravenhorst (Coleoptera: Staphylinidae: Paederinae) from North America north of Mexico are reviewed and 41 species are recognized. Morphology and mitochondrial COI sequence data were used to guide species designations in three flightless lineages endemic to the southern Appalachian Mountains, a biologically diverse region known for cryptic diversity. Using a combination of phylogeny, algorithm-based species delimitation analyses, and genitalic morphology, five new cryptic species are described and possible biogeographic scenarios for their speciation hypothesized: L.balsamense Haberski & Caterino, sp. nov., L.camplyacra Haberski & Caterino, sp. nov., L.islae Haberski & Caterino, sp. nov., L.lividum Haberski & Caterino, sp. nov., L.smokiense Haberski & Caterino, sp. nov. Five additional species are described: L.absconditum Haberski & Caterino, sp. nov., L.hardeni Haberski & Caterino, sp. nov., L.lapidum Haberski & Caterino, sp. nov., L.solum Haberski & Caterino, sp. nov., and L.thompsonorum Haberski & Caterino, sp. nov. Two species are transferred from Lathrobium to Pseudolathra Casey: Pseudolathraparcum (LeConte, 1880), comb. nov. and Pseudolathratexana (Casey, 1905), comb. nov. Twenty-six names are reduced to synonymy. Lectotypes are designated for 47 species. Larvae are described where known, and characters of possible diagnostic value are summarized. Species diagnoses, distributions, illustrations of male and female genitalia, and a key to Lathrobium species known from the Nearctic region (including several introduced species) are provided.

Molecular phylogeny of the common wall lizard Podarcis muralis (Squamata: Lacertideae) in the southern Balkans

Abstract The lacertid wall lizards of the genus Podarcis (Wagler, 1830) originate from Western Europe and are divided into 24-25 species (Speybroeck et al., 2020). Despite the abundance of phylogenetic studies referring to the genus, the relationships among certain species, as well as the taxonomic status of some genealogical lineages, remain unclear due to great genetic diversity. The common wall lizard Podarcis muralis has a relatively wide distribution and despite the existence of various molecular studies focused on this species, its Greek populations had never been thoroughly sampled until now. To fill in this geographical gap, we sampled the species’ Greek distribution and constructed phylogenies that uncovered the presence of at least five monophyletic lineages that correspond to different geographic regions. Furthermore, species delimitation analyses assigned all lineages to a single species diversifying during the early Pleistocene (c. 1.93 mya). The strong association of the genetic lineages with specific geographical regions coupled with the Pleistocene diversification of the group imply the presence of multiple refugia within Greece and, by extension, the Balkan peninsula, supporting a refugia-within-refugia scenario. Finally, in an effort to clarify the position of these new samples within the larger phylogeny of P. muralis, a larger phylogeny was constructed which indicated that the Greek populations cluster with the central European, Italian and Turkish populations of the species.

Morphological and molecular characterization of brown-banded broodsacs and metacercariae of Leucochloridium (Trematoda: Leucochloridiidae) parasitizing the semi-slug Omalonyx unguis (Succineidae) in Argentina

Trematodes of the genus Leucochloridium exhibit an unusual transmission strategy among mollusks (intermediate host). The fully developed sporocyst, housing encysted metacercariae, displays vivid coloration and rhythmic activity in the snail's tentacle, mimicking insect larvae. These strategies attract insectivorous birds, their final hosts, thereby increasing the chances of completing their life cycle. In South America, the reports of adults and larval stages of Leucochloridium are scarce. Brown-banded broodsac of Leucochloridium sp. were obtained from Omalonyx unguis collected in a shallow lake from Corrientes Province, Argentina. Here, we morphologically characterized the larval stages (broodsac and metacercaria), identified the parasite through DNA sequences from nuclear 28S-rRNA (28S) and the mitochondrial cytochrome c oxidase I (COI) genes, and explored its evolutionary affinities with the Leucochloridium species available in GenBank. The present broodsac displays brown bands, with a yellowish background in the first two-thirds and yellowish-white in the last third. Based on morphological comparisons, the broodsac and metacercaria described in this study could not be conclusively categorized under any known South American species of Leucochloridium. In relation to the phylogenetic reconstructions, Leucochloridium sp. consistently clustered with L. perturbatum, and species delimitation analyses resulted in recognized Leucochloridium sp. from Argentina as a distinct species. The DNA sequences obtained in this study constitute the first genetic data generated for sporocyst broodsacs in South America. Future studies, incorporating morphology, genetic, and biological data, will be essential for both species identification and the elucidation of leucochloridiid diversity in the region.

Violins we see, species we don’t… Species delimitation of the spider genus Loxosceles Heineken & Lowe (Araneae: Sicariidae) from North America using morphological and molecular evidence

In modern systematics, different sources of evidence are commonly used for the discovery, identification, and delimitation of species, especially when morphology fails to delineate between species or in underestimated species complexes or cryptic species. In this study, morphological data and two DNA barcoding markers—cytochrome c oxidase subunit I (COI) and internal transcribed spacer 2 (ITS2)—were used to delimit species in the spider genus Loxosceles from North America. The molecular species delimitation analyses were carried out using three different methods under the corrected p-distance Neighbor-Joining (NJ) criteria: 1) Assemble Species by Automatic Partitioning (ASAP), 2) General Mixed Yule Coalescent model (GMYC), and 3) Bayesian Poisson Tree Processes (bPTP). The analyses incorporated 192 terminals corresponding to 43 putative species of Loxosceles, of which 15 are newly recognized herein, as putative new species, based on morphology and congruence between molecular methods with COI. The average intraspecific genetic distance (p-distance) was <2%, whereas the average interspecific genetic distance was 15.6%. The GMYC and bPTP molecular methods recovered 65-79 and 69 species respectively, overestimating the diversity in comparison with morphology, whereas the ASAP method delimited 60 species. The morphology of primary sexual structures (males palps and female seminal receptacles) was congruent with most of the molecular methods mainly with COI, showing that they are robust characters for identification at the species level. For species delimitation COI was more informative than ITS2. The diversity of Loxosceles species is still underestimated for North America, particularly in Mexico which holds the highest diversity of this genus worldwide.  

Diversity in Cyanidiophyceae: Cyanidiofrigus pintoensis gen. et sp. nov. within polyextremophilic red algae (Rhodophyta)

ABSTRACT The polyextremophilic red algal class Cyanidiophyceae inhabits a wide range of extreme habitats (e.g. acidic geothermal areas and dim-light caves), and shows various cell morphologies (e.g., subspherical and club-shape) and trophic strategies (e.g., photoautotrophy, heterotrophy and mixotrophy). Historically, inconsistent observations of morphology and physiology have hindered taxonomic advancements in Cyanidiophyceae despite indications of species diversity from molecular studies. Here we revisited this taxonomic conundrum and explored their cryptic speciation based on multi-locus and morpho-physiological evidence examined from expanded taxa sampling, including 20 cultures and one environmental sample. Our multi-locus phylogeny revealed two well-supported monophyletic lineages: the C-lineage that is generically rich (including Cavernulicola, Cyanidiococcus, Cyanidiofrigus, Cyanidioschyzon, Cyanidium, Gronococcus, and Sciadococcus) and the G-lineage that currently only contains the genus Galdieria. Species delimitation analyses revealed at least 21 species in Cyanidiophyceae. Although our morpho-physiological observations failed to differentiate closely related species apart within a genus, we propose Cyanidiofrigus pintoensis gen. et sp. nov. as this species is in a highly divergent lineage with much lower thermal tolerance than other recognized species. Overall, our study fills the taxonomic knowledge gaps and expands the number of known species in Cyanidiophyceae.

Unveiling taxonomic diversity in the deep-sea fish genus Notacanthus (Notacanthiformes: Notacanthidae) with description of Notacanthus arrontei n. sp.

Notacanthid fishes constitute a common part of benthopelagic deep-sea fish communities on seamounts and continental slopes around the world. However, their highly conserved morphology and the usual lack of information on deep-water organisms make it difficult to appropriately address their biodiversity. A multidisciplinary approach combining morphological data with a DNA-based species delimitation analyses was used to explore the taxonomy of Notacanthus species. For this purpose, morphological and molecular data were obtained from 43 individuals, and the resulting information was combined with the available data. The results showed the occurrence of Notacanthus arrontei n. sp. from the Iberian Peninsula and highlighted several taxonomic conundrums regarding the Notacanthus genus. For instance, no significant differences were found between Notacanthus indicus and the recently described Notacanthus laccadiviensis, questioning its taxonomic status. Similarly, the result of the species delimitation molecular analysis coincided with previous DNA barcoding studies supporting the snubnosed spiny eel Notacanthus chemnitzii as a species complex that requires further research. Moreover, two unidentified records from the Indian Ocean were confirmed to belong to an unknown species pending formal description, and barcoding data show for the first time the occurrence of the shortfin spiny eel Notacanthus bonaparte in the Australia-New Zealand area. This research confirms the existence of important gaps in the knowledge of notacanthid fishes and represents a step forward toward a better understanding of their biological diversity.

DNA Barcoding Supports "Color-Pattern''-Based Species of Stictochironomus from China (Diptera: Chironomidae).

The genus Stictochironomus (Diptera: Chironomidae) has an almost worldwide distribution, with more than 30 species. However, species delimitation and identification based on the markings on the wings and legs are controversial and uncertain. In this study, we focused on color patterns to review the adults of the genus from China, and two new species (S. trifuscipes sp. nov. and S. quadrimaculatus sp. nov.) are described and figured. DNA barcodes can accurately separate the two new species with specific color patterns. However, heterospecific individuals form a monophyletic cluster in the phylogeny tree. For example, S. maculipennis (Meigen) and S. pictulus (Meigen), which have a lower interspecific genetic divergence, form a single clade. Sequences with the same species name but with high intraspecific distance form more than one phylogenetic clade, such as S. sticticus (Fabricius) of three clades, S. pictulus of four clades, S. akizukii (Tokunaga) and S. juncaii Qi, Shi, and Wang of two clades, might have potential cryptic species diversity. Species delimitation analysis using ASAP, PTP, and GMYC clearly delineated them as separate species. Consequently, color patterns are a good diagnostic characteristic for species delimitation in Stictochironomus. The distance-based analysis shows that a threshold of 4.5-7.7% is appropriate for species delimitation in Stictochironomus. Additionally, an updated key including color pattern variation for male adults of known Stictochironomus species from China is provided.

Endemic and cryptic: different biogeographic histories of three Italian blister beetles of the genus Meloe (Coleoptera: Meloidae: Meloinae: Meloini)

Abstract The Italian geographic region is characterized by complex and diversified biogeographic patterns and is represented by a high number of endemic species. Endemic species characterized by a limited distribution range should be a primary concern in conservation. This article aimed to investigate the phylogenetic and biogeographic relationships of 2 Italian endemic species of the wingless blister beetle genus Meloe Linnaeus, 1758: Meloe (Eurymeloe) apenninicus and Meloe (E.) baudii. Our inferences, based on morphological characters, 2 mitochondrial (16S and COI) and 2 nuclear (CAD and 28S) markers and the use of 3 species delimitation analyses approaches, pointed out the presence of a new Italian endemic species (M. (E.) digiuliorumsp. n.), here described, and 3 different patterns of phylogenetic and biogeographic affinities. M. digiuliorum is close to the Spanish endemic M. orobatescomb. n., revealing a possible fragmentation of the ancestor range in the Pleistocene (ca. 0.84 Mya) followed by isolation in Italy and Spain. M. apenninicus is the sister species of the European-Anatolian M. rugous and M. cfr. rugosus, and this pattern originated around the Plio-Pleistocene boundary (ca. 2.83 Mya) likely influenced by the climatic fluctuations and the presence of the Alpine barrier. Finally, 2 subspecies were referred to M. baudii: the nominal one, endemic to Italy, and the Turanian-E European M. b. glazunovistat. n., disclosing a third more recent (ca. 0.64 Mya) pattern of biogeographic disjunction.

High species diversity of Phintella and Phintella-like spiders (Araneae: Salticidae) in Vietnam revealed by DNA-based species delimitation analyses.

Salticidae (jumping spiders) usually exhibit pronounced sexual dimorphism in adult morphology, particularly body coloration and size and shape of the first legs. Consequently, the male and female from the same species might be erroneously assigned to different species or even different genera, which could generate synonymies in classification if only morphological data were used. Phintella is a species-rich genus of Salticidae, which currently exhibits 76 named species. However, the male-female counterpart is unknown for nearly half of the species. In this study, we used a molecular approach to delineate the species boundaries for Phintella and Phintella-like specimens collected in Vietnam, using morphological information as supporting data. We used three gene fragments (mitochondrial COI, 16S-ND1, and nuclear 28S) and biogeographical considerations for species delimitation. A total of 22 putative species were recognized: 18 species of the genus Phintella, one species of the genus Lechia (L. squamata), and three species of the genus Phinteloides. Eleven undescribed species were discovered, of which seven have a male-female combination, two species have only males, and two species have only females. The crown age of Phintella was estimated at the Serravallian stage of the Miocene after the increase of species number around 16 MYA. The crown ages of most putative species recognized in this study were estimated in the Pleistocene, and the divergence among sister species likely occurred from the mid-Miocene to the Pliocene. Our ancestral range reconstruction results showed that the diversification of our ingroup was governed by progressive dispersal events, i.e., Phintella and their related species in Vietnam diversified while expanding their range on the continent. Our results provide fundamental biodiversity data for a high-diversity genus in Vietnamese Phintella spiders.

Discovery of a new species of Synergus (Hymenoptera, Cynipidae, Synergini) based on morphology and molecular data.

A new species of gall inquiline, Synergusdilatatussp. nov., is described from Hubei Province, China. Morphological descriptions, photographs and biological information are provided. Mitochondrial cytochrome oxidase (COI) sequences of the new species were newly obtained and a molecular species delimitation analysis of 12 species of Synergus performed using the ASAP method recovered 16 molecular operational taxonomic units, providing support for recognition of the new species. The results also highlight a few conflicts between morphological and molecular species delimitations in Synergus.

A new species of Raorchestes (Anura, Rhacophoridae) from Yunnan Province, China.

A new bush frog species is described from Yunnan, China, based on phylogenetic analyses, species delimitation analyses, and morphological comparisons. Raorchesteshekouensissp. nov. is distinguished from all other congeners by a combination of 11 morphological characters. The new species brings the current number of Raorchestes species in China to ten, nine of which are distributed in Yunnan. Molecular analyses supported an unnamed lineage previously recorded as "Raorchestesgryllus" in northern Vietnam. Further studies including additional samples are necessary to clarify the species diversity and boundaries of Raorchestes in China and Indochina.

Mitogenomes Provide Insights into the Species Boundaries and Phylogenetic Relationships among Three Dolycoris Sloe Bugs (Hemiptera: Pentatomidae) from China.

(1) Background: The three sloe bugs, Dolycoris baccarum, Dolycoris indicus, and Dolycoris penicillatus, are found in the Chinese mainland and are morphologically similar. The species boundaries and phylogenetic relationships of the three species remain uncertain; (2) Methods: In this study, we generated multiple mitochondrial genomes (mitogenomes) for each of the three species and conducted comparative mitogenomic analysis, species delimitation, and phylogenetic analysis based on these data; (3) Results: Mitogenomes of the three Dolycoris species are conserved in nucleotide composition, gene arrangement, and codon usage. All protein-coding genes (PCGs) were found to be under purifying selection, and the ND4 evolved at the fastest rate. Most species delimitation analyses based on the COI gene and the concatenated 13 PCGs retrieved three operational taxonomic units (OTUs), which corresponded well with the three Dolycoris species identified based on morphological characters. A clear-cut barcode gap was discovered between the interspecific and intraspecific genetic distances of the three Dolycoris species. Phylogenetic analyses strongly supported the monophyly of Dolycoris, with interspecific relationship inferred as (D. indicus + (D. baccarum + D. penicillatus)); (4) Conclusions: Our study provides the first insight into the species boundaries and phylogenetic relationships of the three Dolycoris species distributed across the Chinese mainland.

First occurrence of the genus Pleurobranchaea Leue, 1813 (Pleurobranchida, Nudipleura, Heterobranchia) in British waters, with the description of a new species

In the north-eastern Atlantic and Mediterranean Sea, the pleurobranchid genus Pleurobranchaea Leue, 1813 is represented by two species, Pleurobranchaea meckeli (Blainville, 1825) and Pleurobranchaea morosa (Bergh, 1892). The former is a well-known species distributed from northern Spain to Senegal and the Mediterranean Sea, while the second is a poorly-described species. In this contribution, species delimitation analyses (ABGD and COI/16S p-distances) identified a third undescribed Pleurobranchaea species from samples collected in south-western UK waters and the Gulf of Cadiz (SW Spain). This new species, Pleurobranchaea britannicasp. nov., is also supported by several morphological synapomorphies. The British specimens constitute the first occurrence of the genus Pleurobranchaea in UK waters.

Description of a new species of Phoxinus from the Ergene River (Aegean Sea Basin) in Türkiye (Actinopterygii, Leuciscidae)

Phoxinus radeki, a new species, is described from the Ergene River (Aegean Sea Basin). It is distinguished from Phoxinus species in Türkiye and the adjacent area by having the scales of the breast, scaled but separated unscaled area anteriorly, short dark rectangular blotches along the lateral line between the lateral line and belly yellowish in both males and females, body depth dorsal fin origin 16–21% SL, caudal peduncle depth 8–10% SL. Additionally, molecular results demonstrated that the new species differed from its closest congeners with a mean genetic distance value of 3.08% (min. 2.82–max. 3.29) and moderately support values in cytochrome b (Cyt b) gene partial sequences (1064 bp.). Further, the species delimitation analysis identified the new species as a single MOTU independent of other Phoxinus species.

Two new species of Callophyllis (Rhodophyta, Kallymeniaceae) from the Russian Pacific coast

ABSTRACT Seven species of Callophyllis have been known off the Pacific coast of Russia; hovewer, molecular data have been obtained only for three species. In this study we re-examined the genus along the Russian Pacific coast using a comparative morphological study and molecular analyses based on rbcL and nrLSU. Five genetic species were identified on the Russian coast based on phylogenetics and species delimitation (ASAP and p-distance) analyses; while C. beringensis, C. papulosa and C. platyna were outscore of the analyses. The results of the molecular analyses uncovered one undescribed species, which we named C. selivanovae sp. nov. The divergence between this species and other species of the genus varied from 1.16% to 5.66%, while intraspecific divergence in the genus was in a range of 0.00%–0.22%. In phylogenetic trees C. selivanovae was recognized as sister to a diverse clade including C. thompsonii, C. beringensis, C. violacea, C. flabellulata and C. variegata from the Pacific coast of Canada. Callophyllis selivanovae from the southeastern coast of Kamchatka is morphologically close to C. beringensis, described from St. Paul Island (Bering Sea); the two species differ in features of branching, shape and size of the terminal branches. We propose a new name, C. perestenkoae sp. nov., for the algae previously listed in the Russian flora as ‘C. flabellata’. Pacific specimens assigned to C. perestenkoae differ from C. flabellata from the type locality (Atlantic, France) in having irregular branching, thicker apical branches, and smaller cystocarps. We also filled in the gaps in the description of C. radula for which procarp and tetrasporangia are described herein for the first time.

Global species delimitation of the cosmopolitan marine littoral earthworm Pontodrilus litoralis (Grube, 1855)

The marine littoral earthworm Pontodrilus litoralis (Grube, 1855) is widely distributed and is reported as a single species. This study utilized an integrative taxonomic approach based upon morphological examination, phylogenetic reconstruction, and molecular species delimitation, to test whether the taxon is a single species or a species complex. For this, a total of 114 P. litoralis specimens collected from North America, Africa, Australia and Oceania, Europe and Asia were used. The phylogenetic analyses revealed deeply divergent mitochondrial lineages and a high level of genetic diversity among P. litoralis populations. Both single and multi-locus species delimitation analyses yielded several molecular operational taxonomic units. Therefore, due to the homogeneity of morphological characteristics, it is likely that the morphospecies P. litoralis is a complex of four or more cryptic species, suggesting that more sampling is required and that the population structure genetic data and gene flow need to be investigated.

Towards a Canary Islands barcode database for soil biodiversity: revealing cryptic and unrecorded mite species diversity within insular soils.

Soil arthropod diversity contributes to a high proportion of the total biodiversity on Earth. However, most soil arthropods are still undescribed, hindering our understanding of soil functioning and global biodiversity estimations. Inventorying soil arthropods using conventional taxonomical approaches is particularly difficult and costly due to the great species richness, abundance and local-scale heterogeneity of mesofauna communities and the poor taxonomic background knowledge of most lineages. To alleviate this situation, we have designed and implemented a molecular barcoding framework adapted to soil fauna. This pipeline includes different steps, starting with a morphology-based selection of specimens which are imaged. Then, DNA is extracted non-destructively. Both images and voucher specimens are used to assign a taxonomic identification, based on morphology that is further checked for consistency with molecular information. Using this procedure, we studied 239 specimens of mites from the Canary Islands including representatives of Mesostigmata, Sarcoptiformes and Trombidiformes, of which we recovered barcode sequences for 168 specimens that were morphologically identified to 49 species, with nine specimens that could only be identified at the genus or family levels. Multiple species delimitation analyses were run to compare molecular delimitations with morphological identifications, including ASAP, mlPTP, BINs and 3% and 8% genetic distance thresholds. Additionally, a species-level search was carried out at the Biodiversity Databank of the Canary Islands (BIOTA) to evaluate the number of species in our dataset that were not previously recorded in the archipelago. In parallel, a sequence-level search of our sequences was performed against BOLD Systems. Our results reveal that multiple morphologically identified species correspond to different molecular lineages, which points to significant levels of unknown cryptic diversity within the archipelago. In addition, we evidenced that multiple species in our dataset constituted new records for the Canary Islands fauna and that the information for these lineages within online genetic repositories is very incomplete. Our study represents the first systematic effort to catalogue the soil arthropod mesofauna of the Canary Islands and establishes the basis for the Canary Islands Soil Biodiversity barcode database. This resource will constitute a step forward in the knowledge of these arthropods in a region of special interest.

Taxonomy and distribution of three species of Barleeia (Mollusca, Gastropoda, Littorinimorpha, Barleeiidae) in the intertidal zone off the coast of China, with description of a new species, Barleeia qilu Han, Qi & Kong, n. sp.

ABSTRACT Barleeiids are common marine microgastropods worldwide. Three species of Barleeia (Barleeia annamitica, Barleeia qilu n. sp. and Barleeia dunedini) found in the intertidal zone off the coast of China are described in this study. Morphological comparisons and species delimitation analyses using the universal mitochondrial COI gene sequence showed the distinctiveness of three species. Barleeia qilu n. sp., differentiated by its pointed apex and sutural channelling, was identified as a new species following morphological observation and phylogenetic analysis. Barleeia dunedini, previously considered as Ansola angustata (Pilsbry, 1901), has emerged as a distinct species and is probably the most widely distributed barleeiid in China. Barleeia annamitica, which has a broader distribution than previously recorded, is reported in China for the first time. Additionally, we propose to reassign Ansola angustata to the genus Barleeia based on the phylogram. Morphological illustrations, diagnoses, descriptions, and their approximate distribution along the coast of China are provided for each species. This study improves our understanding of the species composition, distribution and diversity of Barleeia in the intertidal zone of China.   urn: lsid: zoobank.org:pub:7EFA6806-3A9E-40EC-A639-5AF4DB8D5CC7