DNA Barcoding Markers Research Articles

Authentication of medicinal herb Wikstroemia indica using novel DNA markers derived from the chloroplast genome sequences

The processed root of Wikstroemia indica, also known as Wikstroemiae Radix (WR), is known as a time-honored traditional herbal medicine demonstrating health-promoting properties. Although W. indica is valuable, its molecular information on this medicinal plant is limited. In this study, we reported the complete chloroplast (cp) genome sequences of W. indica and its congener, W. nutans, the latter of which is highly identical to W. indica in both their natural distributions and morphological characteristics. The cp genomes of W. indica and W. nutans were 151,746 bp and 149,776 bp in size, respectively, and were predicted to contain the same number of genes, including 78 protein-coding, 37 tRNA, and eight rRNA genes. Genome comparison of W. indica showed that mutational hotspots were present despite low intraspecific variations were detected between two different accessions. Although phylogenetic analyses revealed that the two closely-related species of Wikstroemia were sisters, presence of variations in the sequence and mutational hotspots demarcated these two species apart. To authenticate commercial WR products sold in the market, three sets of novel indel markers and two sets of novel DNA barcoding markers from the cp genome sequences were developed. However, only the indel marker ndhK-trnV and the DNA barcoding marker, ccsA-psaC were proven useful in discriminating W. indica from W. nutans; while the former is even capable to delimit W. indica from adulterants of other related species. The findings of this study are useful for the molecular development of W. indica and also contribute to the effort in species authentication, trade monitoring and drug regulation in the local herbal industry.

Understanding the molecular evolution of tiger diversity through DNA barcoding marker ND4 and NADH dehydrogenase complex using computational biology.

Currently, Tigers (the top predator of an ecosystem) are on the list of endangered species. Thus the need is to understand the tiger's population genomics to design their conservation strategies. We analyzed the molecular evolution of tiger diversity using NADH dehydrogenase subunit 4 (ND4), a significant electron transport chain component. We have analyzed nucleotide composition and distribution pattern of ND genes, molecular evolution, evolutionary conservation pattern and conserved blocks of NADH, phylogenomics of ND4, and estimating species divergence, etc., using different bioinformatics tools and software, and MATLAB programming and computing environment. The nucleotide composition and distribution pattern of ND genes in the tiger genome demonstrated an increase in the number of adenine (A) and a lower trend of A+T content in some place of the distribution analysis. However, the observed distributions were not significant (P > 0.05). Evolutionary conservation analysis showed three highly align blocks (186 to 198, 406 to 416, and 527 to 545). On mapping the molecular evolution of ND4 among model species (n = 30), we observed its presence in a broader range of species. ND4 based molecular evolution of tiger diversity and time divergence for a tiger (20 different other species) shows that genus Panthera originated more or less at a similar time. The nucleotide composition and nucleotide distribution pattern of tiger ND genes showed the evolutionary pattern and origin of tiger and Panthera lineage concerning the molecular clock, which will help to understand their adaptive evolution.

Barcode UK: A complete DNA barcoding resource for the flowering plants and conifers of the United Kingdom.

DNA barcoding and metabarcoding provide new avenues for investigating biological systems. These techniques require well-curated reference libraries with extensive coverage. Generating an exhaustive national DNA barcode reference library can open up new avenues of research in ecology, evolution and conservation, yet few studies to date have created such a resource. In plant DNA barcoding, herbarium collections provide taxonomically robust material but also pose challenges in lab processing. Here, we present a national DNA barcoding resource covering all of the native flowering plants and conifers of the United Kingdom. This represents 1,482 plant species, with the majority of specimens (81%) sourced from herbaria. Using Sanger sequencing of the plant DNA barcode markers, rbcL, matK, and ITS2, at least one DNA barcode was retrieved from 98% of the UK flora. We sampled from multiple individuals, resulting in a species coverage for rbcL of 96% (4,477 sequences), 90% for matK (3,259 sequences) and 75% for ITS2 (2,585 sequences). Sequence recovery was lower for herbarium material compared to fresh collections, with the age of the specimen having a significant effect on the success of sequence recovery. Species level discrimination was highest with ITS2, however, the ability to successfully retrieve a sequence was lowest for this region. Analyses of the genetic distinctiveness of species across a complete flora showed DNA barcoding to be informative for all but the most taxonomically complex groups. The UK flora DNA barcode reference library provides an important resource for many applications that require plant identification from DNA.

Dentex dentex Frauds: Establishment of a New DNA Barcoding Marker

The common dentex (Dentex dentex (Linnaeus, 1758)) is an iconic fish in the Mediterranean diet. Due to its commercial and organoleptic importance, this sparid is highly appreciated in European markets and is often subjected to species substitution frauds. Comparative mitogenomics is a suitable approach for identifying new and effective barcode markers. This study aimed to find a molecular tag useful for unequivocally discriminating the sparid species D. dentex. The comparison of the complete mitochondrial DNA (mtDNA) sequences of 16 sparid species allowed us to highlight the potential of the NAD2 gene for direct identification purposes. Common dentex-specific primers were created and successfully evaluated by end-point and real-rime PCR (Polymerase Chain Reaction) for several fish species, achieving amplification only in the D. dentex. The method proposed in this study appears fast, simple, and inexpensive and requires affordable instrumentation. This approach provides unambiguous results for the common dentex authentication without the sequencing step. The presence/absence assay for D. dentex can be executed in a few hours of lab work. Therefore, national authorities responsible for food safety and traceability could apply and make full use of DNA-testing methods for deterring operators from false seafood declarations.

Is cytochrome c oxidase subunit I (COI) the right DNA barcoding marker for the Chaetopteryx villosa group?

Chaetopteryx villosa (Fabricius, 1798) is a caddisfly species distributed throughout Europe, except in the Balkan and Apennine Peninsula. However, phylogenetically close species belonging to the C. villosa group are widespread throughout entire Europe. Species of this group (C. villosa, C. gessneri, C. fusca, C. sahlbergi, C. atlantica, C. bosniaca, C. vulture, and C. trinacriae) have distinct distributions with some overlaps. Adult forms of these species are morphologically similar, whereas larval morphology is only known for some species. There are also indications of species hybridization (e.g., C. villosa x fusca). Presumably, the molecular approach for the species determination of this group would be highly beneficial. In the BOLD database, there are 154 specimens with COI-5P barcodes of C. villosa species. Out of the remaining species, C. sahlbergi has 27 specimens with a barcode, C. fusca 20, C. gessneri 5, C. bosniaca 5, and C. atlantica 1, whereas sequences from the species C. vulture and C. trinacriae are missing. Therefore, we tested the power of discrimination of the COI-5P marker in the C. villosa group, as the most common barcoding markers for species identification in animals. Only sequences from public records originating from experienced research groups or taxonomists and containing a specimen photograph were taken as input. A total of 75 sequences from the BOLD database were obtained. Out of these sequences, 11 belonged to C. fusca, 5 to C. gessneri, 52 to C. villosa, 5 to C. bosniaca, and 2 to C. sahlbergi. For the generation of overview trees, COI-5P barcodes of Rhyacophila fasciata and Rh. nubila were used as outgroups. All sequences were trimmed at 5’ and 3’ ends, resulting in a final alignment length of 516 base pairs. Multiple sequence alignments and editing were done in the MEGA-X software. Analysis of nucleotide polymorphism was done in DNASP6 software. MEGA-X was used to calculate the pairwise distance and overall mean p-distance, and to construct the overview trees. Analysis of DNA polymorphism revealed 14 haplotypes of C. villosa, 3 haplotypes of C. fusca, 2 haplotypes of C. gessneri, and one for species C. bosniaca and C. sahlbergi. There were no significant interspecific and intraspecific differences among haplotypes based on pairwise distances. The p-distance between one of the haplotypes of C. fusca and C. villosa was 0.000, whereas the p-distance among haplotypes of C. villosa varied from 0.001 to about 0.055. The mean overall p-distance among haplotypes of all species equaled 0.03. No species-specific clusters were observed when phylogenetic trees were constructed except for C. gessneri, regardless of the method used (i.e., NJ, UPGMA, ML, ME, or MP). To minimize the possibility of species misidentification, we used only records submitted by NTNU-Norwegian University of Science and Technology (Norway), SNSB-Zoologische Staatssammlung Muenchen (Germany), Zoologisches Forschungsmuseum Alexander Koenig (Germany), University of Oulu, Zoological Museum (Finland), prof Hans Malicky and prof Mladen Kučinić. No records identified as hybrids were included in the analyses. With the exception of C. gessneri, COI-5P marker failed to separate the species of the C. villosa group. However, it is highly unlikely that poor species determination was the basis for such a result. To enable the comprehensive and unbiased evaluation of the relationships within this group, data coverage in BOLD database for most of the studied species should be enhanced, encompassing different geographical distribution of samples. Further studies are needed to detect the array of molecular markers suitable for the species delineation in a complex group such as C. villosa.

Morpho-molecular identification and first report of Fusarium equiseti in causing chilli wilt from Kashmir (Northern Himalayas)

Chilli (Capsicum annuum L.) is one of the most significant vegetable and spice crop. Wilt caused by Fusarium Sp. has emerged as a serious problem in chilli production. Internal transcribed spacer (ITS) region is widely used as a DNA barcoding marker to characterize the diversity and composition of Fusarium communities. ITS regions are heavily used in both molecular methods and ecological studies of fungi, because of its high degree of interspecific variability, conserved primer sites and multiple copy nature in the genome. In the present study we focused on morphological and molecular characterization of pathogen causing chilli wilt. Chilli plants were collected from four districts of Kashmir valley of Himalayan region. Pathogens were isolated from infected root and stem of the plants. Isolated pathogens were subjected to DNA extraction and PCR amplification. The amplified product was sequenced and three different wilt causing fungal isolates were obtained which are reported in the current investigation. In addition to Fusarium oxysporum and Fusarium solani, a new fungal species was found in association with the chilli wilt in Kashmir valley viz., Fusarium equiseti that has never been reported before from this region. The studies were confirmed by pathogenicity test and re-confirmation by DNA barcoding.

Biosystematic Study on Some Egyptian Species of Astragalus L. (Fabaceae)

Astragalus L. is one of the largest angiosperm complex genera that belongs to the family Fabaceae, subfamily Papilionoideae or Faboideae under the subtribe Astragalinae of the tribe Galegeae. The current study includes the whole plant morphology, DNA barcode (ITS2), and molecular marker (SCoT). Ten taxa representing four species of Astragalus were collected from different localities in Egypt during the period from February 2018 to May 2019. Morphologically, identification and classification of collected Astragalus plants occurred by utilizing the light microscope, regarding the taxonomic revisions of the reference collected Astragalus specimens in other Egyptian Herbaria. For molecular validation, ten SCoT primers were used in this study, producing a unique banding pattern to differentiate between ten samples of Astragalus taxa which generated 212 DNA fragments with an average of 12.2 bands per 10 Astragalus samples, with 8 to 37 fragments per primer. The 212 fragments amplified were distributed as 2 monomorphic bands, 27 polymorphic without unique bands, 183 unique bands (210 Polymorphic with unique bands), and ITS2 gene sequence was showed as the optimal barcode for identifying Astragalus L. using BLAST searched on NCBI database, and afterward, analyzing the chromatogram for ITS region, 10 samples have been identified as two samples representing A. hauarensis, four samples representing A. sieberi, three samples representing A. spinosus and one sample representing A. vogelii. Based on the ITS barcode, A. hauarensis RMG1, A. hauarensis RMG2, A. sieberi RMG1, A. sieberi RMG2, A. sieberi RMG3, A. sieberi RMG4, A. spinosus RMG1, A. spinosus RMG2, A. spinosus RMG3, A. vogelii RMG were deposited into GenBank with accession # MT367587.1, MT367591.1, MT367593.1, MT367585.1, MT367586.1, MT367588.1, MT160347.1, MT367590.1, MT367589.1, MT367592.1, respectively. These results indicated the efficiency of SCoT markers and ITS2 region in identifying and determining genetic relationships between Astragalus species.

Preliminary study: Species identification of Rasbora sumatrana through the cytochrome oxidase subunit I DNA barcoding marker

Rasbora sumatrana or locally known as “seluang” in Malaysia is a pelagic fish. Unlike its other congeneric species is not categorized as an ornamental fish. Samples of the presumed R. sumatrana was obtained from an abandoned swamp in Hulu Langat, Selangor. Initial identification of the samples was conducted based on meristic and morphometric analyses, which showed congruence with R. sumatrana when referenced to FishBase. To complement the analysis, a molecular study was conducted based on the cytochrome oxidase subunit I (COI) DNA barcoding marker. Confirmation of the species identity was done by BLAST results with six voucher sequences of R. sumatrana and other Rasbora species from GenBank. The relationship of Rasbora spp. was analysed by phylogenetic and Automatic Barcode Gap Discovery (ABGD) analysis. Contradicting with morphological and meristic data analysis, both Maximum-Likelihood and Maximum Parsimony phylogenetic tree showed that the currently studied samples did not cluster with R. sumatrana. We believe that they may represent cryptic diversity and are tentatively classified as Rasbora spp.

<em>Potentila indica (Andr.) nov.</em> (wild strawberry) in Sri Lanka is Restricted to a small Climatic Envelop Urging Strict Conservation

Purpose: The nomenclature of the wild strawberries inhabited in Sri Lanka is ambiguous. In Sri Lanka, this species is still named Duchesnea indica which needs a revision. Wild strawberries grow well in natural habitats of upcountry in Sri Lanka. Since the commercial strawberry cultivations gain a popularity in upcountry, the studies on wild strawberry is essential for crop improvement and management.Research Method: In the present study, we conducted extensive field sampling followed by a phylogenetic analysis with the DNA barcoding markers ITS and, trnL-F by using a representative sample of wild strawberry plants in Sri Lanka. The distribution of the species was identified using maximum entropy modeling approaches.Findings: Sri Lankan wild strawberry got placed at subtribe: Potentilla, and clade: Reptans and show a shallow divergence with the species Potentilla indica reported. Thus, we reposition the genus of wild strawberries in Sri Lanka from Duchesnea to Potentilla and hereafter name it as P. indica. The niche model analysis predicted a highly restricted distribution of Sri Lankan wild strawberry in Nuwara-Eliya district over an area of 166.36 km2 in the altitude range of 1546 - 2524 m in a small climatic envelop highlighting the need for urgent conservation measures.Research Limitations: The pop-set for available in literature of P. indica is limited for comparison. Extensive studies based on DNA sequencing is needed for further validation.Originality / Value: Taxonomy, narrow distribution, need of conservation, and phylogenetic distance to Fragaria chiloensis, a progenitor species of cultivated strawberry, are defined for Sri Lankan wild strawberries.

DNA barcoding of native Caucasus herbal plants: potentials and limitations in complex groups and implications for phylogeographic patterns.

DNA barcoding has rapidly become a useful complementary tool in floristic investigations particularly for identifying specimens that lack diagnostic characters. Here, we assess the capability of three DNA barcode markers (chloroplast rpoB, accD and nuclear ITS) for correct species assignment in a floristic survey on the Caucasus. We focused on two herbal groups with potential for ornamental applications, namely orchids and asterids. On these two plant groups, we tested whether our selection of barcode markers allows identification of the “barcoding gap” in sequence identity and to distinguish between monophyletic species when employing distance-based methods. All markers successfully amplified most specimens, but we found that the rate of species-level resolution amongst selected markers largely varied in the two plant groups. Overall, for both lineages, plastid markers had a species-level assignment success rate lower than the nuclear ITS marker. The latter confirmed, in orchids, both the existence of a barcoding gap and that all accessions of the same species clustered together in monophyletic groups. Further, it also allowed the detection of a phylogeographic signal.The ITS marker resulted in its being the best performing barcode for asterids; however, none of the three tested markers showed high discriminatory ability. Even if ITS were revealed as the most promising plant barcode marker, we argue that the ability of this barcode for species assignment is strongly dependent on the evolutionary history of the investigated plant lineage.

Differentiation of Hedyotis diffusa and Common Adulterants Based on Chloroplast Genome Sequencing and DNA Barcoding Markers.

Chinese herbal tea, also known as Liang Cha or cooling beverage, is popular in South China. It is regarded as a quick-fix remedy to relieve minor health problems. Hedyotis diffusa Willd. (colloquially Baihuasheshecao) is a common ingredient of cooling beverages. H. diffusa is also used to treat cancer and bacterial infections. Owing to the high demand for H. diffusa, two common adulterants, Hedyotis brachypoda (DC.) Sivar and Biju (colloquially Nidingjingcao) and Hedyotis corymbosa (L.) Lam. (colloquially Shuixiancao), are commonly encountered in the market. Owing to the close similarity of their morphological characteristics, it is difficult to differentiate them. Here, we sequenced the complete chloroplast genomes of the three species of Hedyotis using next-generation sequencing (NGS). By comparing the complete chloroplast genomes, we found that they are closely related in the subfamily Rubioideae. We also discovered that there are significant differences in the number and repeating motifs of microsatellites and complex repeats and revealed three divergent hotspots, rps16-trnQ intergenic spacer, ndhD and ycf1. By using these species-specific sequences, we propose new DNA barcoding markers for the authentication of H. diffusa and its two common adulterants.

<strong><em>Trichosanthes sunhangii</em> (Cucurbitaceae), a new species from Hubei, China</strong>

Trichosanthes sunhangii D.G.Zhang, Z.M.Li, Qun Liu & T.Deng, a new species of Cucurbitaceae, is described and illustrated. It was collected in Shennongjia Forestry District, Hubei province, east-central China. T. sunhangii is morphologically similar to T. kirilowii Maxim. and T. rosthornii Harms, but can be easily distinguished from them by its bracts, tendrils and fruits. Phylogenetic analyses based on three DNA barcode markers (ITS, matK and rpl20-rps12) indicated that two accessions of T. sunhangii were grouped together (PP=1.00, BP=100 and LP=100) in Sect. Foliobracteola.

Chromosomal and DNA barcode analysis of the Polyommatus (Agrodiaetus) damone (Eversmann, 1841) species complex (Lepidoptera, Lycaenidae).

The Polyommatus (Agrodiaetus) damone (Eversmann, 1841) species complex comprises from 5 to 8 species distributed in southeastern Europe and southern Siberia. Here we used chromosomal and DNA-barcode markers in order to test the taxonomic hypotheses previously suggested for this complex. We revealed that all taxa within this group demonstrate chromosomal stasis and share the same or very similar haploid chromosome number (n = 66 or n = 67). This finding is unexpected since the karyotypes are known to be very diverse and species-specific within the other taxa of the subgenus Agrodiaetus Hübner, 1822. Analysis of the mitochondrial gene COI revealed six diverged clusters of individuals within the complex. Each cluster has a specific geographic distribution and is characterized by distinct morphological features in the wing pattern. The clusters mostly (but not always) correlate with traditionally recognized species. As a result of our study, we describe a new subspecies P. (A.) iphigenides zarmitanussubsp. nov. from Uzbekistan and Tajikistan and show that the taxon originally described as Lycaena kindermanni var. melania Staudinger, 1886 represents a subspecies P. (A.) iphigenides melanius (Staudinger, 1886). Polyommatus (A.) samusi Korb, 2017 (syn. nov.) and P. (A.) melanius komarovi Korb, 2017 (syn. nov.) are considered here as junior subjective synonyms of P. (A.) iphigenides iphigenides (Staudinger, 1886).

Diversity in the Taiwanese Swimming Crabs (Crustacea: Brachyura: Portunidae) Estimated through DNA Barcodes, with Descriptions of 14 New Records.

The swimming crabs (family Portunidae) are distributed worldwide and commonly inhabit estuaries, mangroves, reefs, shallow and the deep sea. Previously, 75 species and 19 genera in this family were known to Taiwan. Our study examined specimens in Taiwanese waters, including the islands, collected between 2016 and 2020 or deposited in museums. Through the cytochrome oxidase subunit I DNA barcode marker and morphological examination, 71 species were identified. The minimum interspecific distances were greater than 4.09%, except in two unresolved groups: Charybdis miles (De Haan, 1835) and Ch. sagamiensis Parisi, 1916, as well as Thranita pelsarti (Montgomery, 1931) and Thr. prymna (Herbst, 1803). In addition, 14 species belonging to nine genera were confirmed as new records to Taiwan, viz. Carupa ohashii Takeda, 1993, Lupocyclus inaequalis (Walker, 1887), Luu. tugelae Barnard, 1950, Lupocycloporus minutus (Shen, 1937), Monomia gladiator (Fabricius, 1798), M. lucida Koch & Ďuriš, 2018, Podophthalmus minabensis Sakai, 1961, Thalamita gatavakensis Nobili, 1906, Tha. spinifera Borradaile, 1902, Thalamitoides quadridens A. Milne-Edwards, 1869, Tho. tridens A. Milne-Edwards, 1869, Thr. cerasma (Wee & Ng, 1995), Thr. coeruleipes (Hombron & Jacquinot, 1846) and Xiphonectes tuberculosus (A. Milne-Edwards, 1861). This study thus raises the total number of Portunidae species in Taiwan to 89.

DNA BARCODING LIBRARY DATABASE OF AQUILARIA MEMBER AND GYRINOPS MEMBER

Aquilaria and Gyrinops are the primary agarwood producer on international trade. For authentication and standardization purposes, it is essential to carry DNA barcoding studies of these genera. DNA barcoding studies on plants need a database of several regions on the plant genome that could act as a barcoding marker. These DNA barcoding markers could be divided into Chloroplasts barcoding and Nuclear barcoding. Several markers have been used for DNA barcoding study of agarwood producer species, including trnL-trnF, matK, rbcL, rpoC1, ycf1 (Chloroplast barcoding), and ITS (Nuclear barcoding). This review breakdown the availability of those DNA barcoding markers on the online genebank database for Aquilaria and Gyrinops. Aquilaria genus has 12 species members, while Gyrinops genus has six species members. The sequence of region trnL-trnF is the only barcoding marker covering all 12 species members of Aquilaria and six species members of Gyrinops. Both ITS and matK have covered nine species among 12 total species members of Aquilaria. The rbcL, rpoC1, and ycf1, respectively, have covered eight, five, and four species members of Aquilaria. Most of the barcoding markers have covered three species members of Gyrinops except for ITS (5 species) and rpoC1 (1 species). However, Gyrinops members have no ycf1 sequence on genebank database. Based on sequence availability on the genebank database, it could be concluded that the trnL-trnF region is the most promising DNA barcoding marker for the Aquilaria and Gyrinops members especially for the phylogenetic analysis purpose.

A taxonomic and molecular survey of the pteridophytes of the Nectandra Cloud Forest Reserve, Costa Rica.

Floristic surveys are crucial to the conservation of biodiversity, but the vast majority of such surveys are limited to listing species names, and few take into account the evolutionary history of species. Here, we combine classical taxonomic and molecular phylogenetic (DNA barcoding) approaches to catalog the biodiversity of pteridophytes (ferns and lycophytes) of the Nectandra Cloud Forest Reserve, Costa Rica. Surveys were carried out over three field seasons (2008, 2011, and 2013), resulting in 176 species representing 69 genera and 22 families of pteridophytes. Our literature survey of protected areas in Costa Rica shows that Nectandra has an exceptionally diverse pteridophyte flora for its size. Plastid rbcL was selected as a DNA barcode marker and obtained for >95% of pteridophyte taxa at this site. Combined molecular and morphological analyses revealed two previously undescribed taxa that appear to be of hybrid origin. The utility of rbcL for species identification was assessed by calculating minimum interspecific distances and found to have a failure rate of 18%. Finally we compared the distribution of minimum interspecific rbcL distances with two other areas that have been the focus of pteridophyte molecular surveys: Japan and Tahiti. The comparison shows that Nectandra is more similar to Japan than Tahiti, which may reflect the biogeographic history of these floras.

Molecular phylogeny of several species of Hoplolaimina (Nematoda: Tylenchida) associated with turfgrass in Korea, with comments on their morphology

Summary Seven species belonging to Suborder Hoplolaimina are characterised using integrative taxonomy, considering both morphological and molecular phylogenetic analyses of the 28S-rRNA, ITS-rRNA and COI gene sequences. It is evident that, as more populations of Pratylenchus zeae are continuously characterised, the species continues to display an ever-increasing intraspecific genetic variation within the 28S-rRNA and ITS-rRNA genes. However, the COI gene sequences exhibit minimum intraspecific variation and thus might be the most powerful DNA barcoding marker for the precise identification of P. zeae and should therefore be recommended as a complementary technique in the identification process of the species. Pratylenchus zeae, Meloidogyne graminicola and Heterodera pratensis are characterised herein for the first time in Korea, while the presence in Korea of P. penetrans, P. scribneri, H. avenae, and M. marylandi, is molecularly confirmed.

Chondrophycus anabeliae and Laurencia digitata (Ceramiales, Rhodophyta) are recorded for the first time for Venezuela expanding their geographic distributions beyond the type localities

Background: Over the course of approximately 12 years, the species of the Laurencia complex have been systematically studied in the tropical and subtropical Atlantic Ocean, showing high diversity (48 species), which has been underestimated for the coast of Venezuela.
 Questions: What is the species diversity of the Laurencia complex in Venezuela?
 Studied species: Chondrophycus anabeliae , Laurencia digitata .
 Study site and dates: Cayo Muerto, Parque Nacional Morrocoy, Estado Falcón, Venezuela, 2015.
 Methods: For molecular studies, the plastid rbc L gene and the mitochondrial DNA barcode marker COI-5P were used, combined with the study of current morpho-anatomical characters used for the identification of the species of the complex.
 Results: The occurrence of Chondrophycus , as currently circumscribed, was confirmed for the first time for Venezuela. Chondrophycus anabeliae and Laurencia digitata are reported for the first time beyond the type localities. Tetrasporophytes are described for the first time for L. digitata .
 Conclusions: Our findings expand the geographic distribution of Ch. anabeliae and L. digitata for the Venezuelan Caribbean and the Atlantic Ocean, respectively.

Discovery of populations endemic to a marine biogeographical transition zone

AbstractAimBiogeographical transition zones are areas of overlap between the faunas of adjacent biogeographical entities. Particularly the well‐defined transition zones along linear coastlines are interesting natural laboratories to study dispersal and incipient speciation. Few studies have explored whether marine biogeographical transition zones harbour biodiversity that is distinct from that of the biogeographical entities they separate. The Wild Coast in eastern South Africa is a poorly studied transition zone between the region's warm‐temperate and subtropical faunas, and is generally considered to be an area of faunal overlap.LocationThe South African portion of the Western Indian Ocean.MethodsSequences of the DNA barcoding marker COI were generated from 306 estuarine sandprawns (Kraussillichirus kraussi) collected at 13 sites. Genetic structure and evolutionary history were assessed using a haplotype network and a Bayesian discrete phylogeographic analysis.ResultTwo populations were identified whose ranges are centred on the Wild Coast, a rare one in the northern portion and a more common one in the central and southern portion of this biogeographical transition zone. These populations are not closely related to each other, but descend from subtropical and warm‐temperate sister populations, respectively. Although genetic distances between populations were low, they exceeded within‐population distances, indicating the presence of a "barcoding gap."ConclusionsThis is the first study to indicate that the Wild Coast marine biogeographical transition zone is not merely an area of faunal overlap, and one of very few studies to have discovered genetically unique populations within a marine biogeographical transition zone. The Wild Coast may harbour additional unique biodiversity that remains to be discovered, including rare species that require protection. More research is required to understand how this environmentally dynamic marine biogeographical transition zone differs from the adjacent biogeographical provinces.

Molecular Detection for Two Abalone Shell-boring Species Polydora haswelli and P. hoplura (Polychaeta, Spionidae) from Korea using 18S rDNA and cox1 Markers

Polydora species (Polychaeta: Spionidae) are morphologically similar and have shell-boring abilities that are harmful to commercially important mollusks; genetic analysis is therefore important for their identification. Here, molecular evidence for Polydora species in Korean cultured abalone (Haliotis discus hannai) is first reported. DNA barcode markers (Nuclear 18S rDNA and mitochondrial cox1 regions) identified Polydora haswelli and P. hoplura in infested abalone shells. The cox1 marker was efficient in detecting Polydora species even in samples contaminated with shell debris. The findings provide useful information for the accurate identification of Polydora species and for monitoring harmful spionids in mollusk aquaculture farms.