DNA barcoding of Naididae (Annelida, Oligochaeta), based on cytochrome C oxidase gene and ITS2 region in China

Exploring the effectiveness of DNA barcoding in species identification is a prerequisite for biodiversity conservation and environmental monitoring. Aquatic oligochaetes could serve as excellent indicators in aquatic monitoring programmes. However, few studies have examined the effectiveness of DNA barcoding in these specific organisms. The mitochondrial cytochrome C oxidase (COI) gene of 83 specimens belonging to 40 species of 18 genera were sequenced in this study. The results showed that there was a barcode gap between species of Naididae and the intraspecific genetic distances of each species were smaller than interspecific genetic distances. The classification results of ABGD (Automatic Barcode Gap Discovery) were consistent with those of morphological identification, except for Tubifex tubifex and Lumbriculus variegatus. All species were successfully distinguished in the phylogenetic tree, based on the ITS2 region, which was coincident with the morphological result. Our results provided evidence that DNA barcoding can be used as an effective and convenient tool for species identification of the family Naididae and even for other aquatic oligochaetes.

Cryptic diversity in the subgenus Oxyphortica (Diptera, Drosophilidae, Stegana)

Phylogenetic relationships of the subgenus Oxyphortica were reconstructed based on two mitochondrial genes (COI and ND2). The results revealed the paraphyly of Oxyphortica and supported high levels of cryptic diversity within this subgenus. By integrating morphological characteristics and molecular evidence, we identified 17 new species as members of Oxyphortica: S. (O.) amphigya sp. nov., S. (O.) armillata sp. nov., S. (O.) ashima sp. nov., S. (O.) bawo sp. nov., S. (O.) crypta sp. nov., S. (O.) gelea sp. nov., S. (O.) hengduanmontana sp. nov., S. (O.) jinmingi sp. nov., S. (O.) mengbalanaxi sp. nov., S. (O.) mouig sp. nov., S. (O.) setipes sp. nov., S. (O.) shangrila sp. nov., S. (O.) tsauri sp. nov., S. (O.) valleculata sp. nov., S. (O.) wanhei sp. nov., S. (O.) yangjin sp. nov. and S. (O.) hypophaia sp. nov. To test the early morphological identifications and confirm the species boundaries, different species delimitation methods, including Automatic Barcode Gap Discovery (ABGD) and Bayesian Phylogenetics and Phylogeography (BP&P), were used, together with traditional distance. All species boundaries were clearly defined. As Oxyphortica species are mainly distributed across Southwest China (e.g., 20 spp. from the Hengduan Mountains), the complex climate and topographic landforms of the area may be responsible for the high levels of species diversity and endemism.

COI mtDNA barcoding and morphology for the description of a new species of ricinuleid of the genus Pseudocellus (Arachnida: Ricinulei: Ricinoididae) from El Triunfo Biosphere Reserve, Chiapas, Mexico

A new species of epigean ricinuleid of the genus Pseudocellus Platnick, 1980 from El Triunfo Biosphere Reserve, Chiapas, Mexico is described. DNA barcoding utilizing mitochondrial cytochrome c oxidase subunit 1 (CO1) and morphology were used for species delimitation. Molecular analyses and species delimitation included four methods: 1) General Mixed Yule Coalescent model (GMYC), 2) Automatic Barcode Gap Discovery (ABGD), 3) Bayesian Poisson Tree Process (bPTP), and 4) Assemble Species by Automatic Partitioning (ASAP). All molecular methods and morphology were consistent in delimiting and recognizing the new species described herein. The average interspecific genetic distance (p-distance) among analyzed species of Pseudocellus was 11.6%. The species is described based on adult males and females: Pseudocellus giribeti sp. nov. This is the seventh species described from Chiapas, which holds the highest number of ricinuleids species for the country. The total number of described species of Pseudocellus from Mexico increases to 21, having the highest species diversity of known ricinuleids worldwide.

Two New Records of Upeneus Spottocaudalis and U. Sundaicus (Perciformes: Mullidae) from the Northern South China Sea Based on the Morphology and DNA Barcoding

In this study, two new records of goatfishes Upeneus spottocaudalis and U. sundaicus from the South China Sea, combing evidence from morphology and DNA barcodes for species identification. ML tree and NJ tree result showed that the sequences of U. spottocaudalis and U. sundaicus were clustered with the homologous sequences form GenBank, respectively, and the intraspecific genetic distances of U. spottocaudalis (0.2%) and U. sundaicus (0.3%) were less than 2%. Automatic Barcode Gap Discovery (ABGD) analysis also supported this result of classification.

DNA barcoding of Naididae (Annelida, Oligochaeta) based on COI and ITS2 genes in China

Exploring the effectiveness of DNA barcoding in species identification is prerequisite for biodiversity conservation and environmental monitoring. Aquatic oligochaete could serve as an excellent indicator in aquatic monitoring programs. However, few studies have examined the effectiveness of DNA barcoding in these specific organisms. The mitochondrial COI gene and nuclear ITS2 gene of 83 specimens belonging to 36 species of 18 genera were sequenced in this study. The results showed that there was a barcode gap between species of Naididae, and the intraspecific genetic distances of each species were smaller than interspecific genetic distances. The classification results of ABGD (Automatic Barcode Gap Discovery) were consistent with those of morphological identification except for Tubifex tubifex and Lumbriculus variegatus. All species were successfully distinguished in the phylogenetic tree based on ITS2 gene, which was coincident with morphological result. Our results provided evidence that DNA barcoding can be used as an effective and convenient tool for species identification of the family Naididae and even aquatic oligochaete.

A contribution to the earthworm diversity (Clitellata, Moniligastridae) of Kerala, a component of the Western Ghats biodiversity hotspot, India, using integrated taxonom

Earthworms (Clitellata, Moniligastridae) of Chaliyar River Malappuram, Eravikulam National Park, Neyyar Wildlife Sanctuary, Parambikulam Tiger Reserve, Peppara Wildlife Sanctuary, Periyar National Park, Shendurney Wildlife Sanctuary and Wayanad Forest, Kerala, a component of the hotspot of Western Ghats, India, were studied by the standard method of taxonomy, and their DNA barcode signatures using the mitochondrial gene cytochrome c oxidase I (COI) were generated for the first time. This study represents eleven species of earthworms of the family Moniligastridae: Drawida brunnea Stephenson, Drawida circumpapillata Aiyer, Drawida ghatensis Michaelsen, Drawida impertusa Stephenson, Drawida nilamburensis (Bourne), Drawida robusta (Bourne), Drawida scandens Rao, Drawida travancorense Michaelsen, Moniligaster aiyeri Gates, Moniligaster deshayesi Perrier, and Moniligaster gravelyi (Stephenson). In the phylogenetic analysis all the species were recovered in both neighbour–joining (NJ) and maximum likelihood (ML) trees with high clade support. The average K2P distance within and between species was 1.2 % and 22 %, whereas the clear barcode gap of 2–5 % was suggested by barcode gap analysis (BGA) of studied species, reflecting the accuracy of characterization. The study presents the first step in the molecular characterization of the native earthworm family Moniligastridae of India. Data published through GBIF (Doi: 10.15470/l2nlhz)

Species delimitation of Margattea cockroaches from China, with seven new species (Blattodea, Ectobiidae, Pseudophyllodromiinae)

Nearly 450 Margattea specimens were collected from 27 locations in China and their morphology was examined. Then 68 Margattea COI sequences were obtained and used to carry out phylogenetic analyses as well as species delimitation analyses using General Mixed Yule Coalescent (GMYC), Automatic Barcode Gap Discovery (ABGD), and Poisson Tree Processes (bPTP). GMYC analysis resulted in 21 molecular operational taxonomic units (MOTUs) (confidence interval: 20–22), which was completely consistent with the result of the bPTP. There were 15 MOTUs using the ABGD method. The number of MOTUs was slightly different from the assigned morphospecies (16). As to the incongruence between molecular and morphological results, we checked the specimens again and made sure that most morphological differences were determined to be intraspecific differences (except the difference between M. angusta and M. mckittrickae), although a large genetic distance existed. Finally, 16 Margattea species from China were defined in this study, of which, seven new species are established, i.e. Margattea deltodonta J-J He & Z-Q Wang, sp. nov., Margattea cuspidata J-J He & Z-Q Wang, sp. nov., Margattea caudata J-J He & Z-Q Wang, sp. nov., Margattea paratransversa J-J He & Z-Q Wang, sp. nov., Margattea disparilis J-J He & Z-Q Wang, sp. nov., Margattea transversa J-J He & Z-Q Wang, sp. nov., and Margattea bicruris J-J He & Z-Q Wang, sp. nov.

Automatic barcode gap discovery reveals diverse clades of Rhipicephalus spp. and Haemaphysalis spp. ticks from small mammals in 'Asir, Saudi Arabia

Background: The ixodid tick genera Rhipicephalus and Haemaphysalis contain several species of medical and/or veterinary importance but their diversity in some regions of the world remains underexplored. For instance, very few modern studies have been performed on the taxonomy of these genera on the Arabian Peninsula.Methods: In this study, we trapped small mammals in the 'Asir Mountains of southwest Saudi Arabia and collected tick specimens for morphological examination and molecular barcoding, targeting three mitochondrial loci: coi, 16S rRNA and 12S rRNA.Results: We obtained a total of 733 ticks (608 Haemaphysalis spp. and 125 Rhipicephalus spp.) from 75 small mammal hosts belonging to six species. All tick specimens were immature except for nine adults recovered from a hedgehog (Paraechinus aethiopicus). Morphologically, the Rhipicephalus ticks resembled Rhipicephalus camicasi but the Haemaphysalis ticks showed differences in palp morphology compared with species previously described from Saudi Arabia. Phylogenetic analysis and automatic barcode gap discovery identified a novel clade of Rhipicephalus sp. representing most of the nymphs. This was most closely related to Rhipicephalus leporis, Rhipicephalus guilhoni, and the tropical lineage of R. sanguineus. The adult ticks and a small proportion of nymphs clustered with R. camicasi sequences from a previous study. Finally, the Haemaphysalis nymphs formed two distinct clades that were clearly separated from all reference sequences but closest to some African species.Conclusions: This high level of tick diversity observed in a single study site of only ~170 km2, on a relatively small number of hosts, highlights the potential for new tick species to be discovered on the Arabian Peninsula.

New record of Cyrtonotula Uvarov, 1939 (Blaberidae, Epilamprinae) from China, with three new species based on morphological and COI data

The genus Cyrtonotula Uvarov, 1939 (Blaberidae, Epilamprinae) is recorded for the first time from Hainan Island, China. Three new species, Cyrtonotula epunctata Wang & Wang, sp. nov., C. maculosa Wang & Wang, sp. nov., and C. longialata Wang & Wang, sp. nov., are described based on morphological data and a molecular analysis using Automatic Barcode Gap Discovery (ABGD). Additional barcode data of blaberid species, including these three new species, are provided to facilitate future species identification. Morphological photographs and habitat photos of these new species, as well as a key to the known species, are provided.

Barcoding a can of worms: testing cox1 performance as a DNA barcode of Nematoda

Accurate taxonomic identifications and species delimitations are a fundamental problem in biology. The complex taxonomy of Nematoda is primarily based on morphology, which is often dubious. DNA barcoding emerged as a handy tool to identify specimens and assess diversity, but its applications in Nematoda are incipient. We evaluated cytochrome c oxidase subunit I (cox1) efficiency as a DNA barcode for nematodes scrutinising 5,241 sequences retrieved from BOLD and GenBank. The samples included genera with medical, agricultural, or ecological relevance: Anguillicola, Caenorhabditis, Heterodera, Meloidogyne, Onchocerca, Strongyloides, and Trichinella. We assessed cox1 performance through barcode gap and Probability of Correct Identification (PCI) analyses, and estimated species richness through Automatic Barcode Gap Discovery (ABGD). Each genus presented distinct gap ranges, mirroring the evolutionary diversity within Nematoda. Thus, to survey the diversity of the phylum, a careful definition of thresholds for lower taxonomic levels should be considered. PCIs were around 70% for both databases, highlighting operational biases and challenges in nematode taxonomy. ABGD inferred higher richness than the taxonomic labels informed by databases. The prevalence of specimen misidentifications and dubious species delimitations emphasise the value of integrative approaches to nematode taxonomy and systematics. Overall, cox1 is a relevant tool for integrative taxonomy of nematodes.