Nuclear rRNA Research Articles

Description of Alvaniawangi Xu, Qi & Kong, sp. nov. (Mollusca, Gastropoda, Littorinimorpha, Rissoidae) from the East China Sea.

Alvaniawangi Xu, Qi & Kong, sp. nov. (Mollusca, Gastropoda, Littorinimorpha, Rissoidae) was discovered within the intertidal zone in the Nanji Islands and Zhoushan Islands, Zhejiang Province, China. It has a radula characteristic of Alvania Risso, 1826, a protoconch sculptured with micro pits and lamellae between spiral lirae, and a teleoconch with growth lines and subobsolete cords. Specimens were examined using an integrative taxonomic approach incorporating morphological observations and phylogenetic analyses of concatenated mitochondrial 16S rRNA and nuclear 28S rRNA gene sequences. The findings suggest that the new species is sister to Alvaniacircinata A. Adams, 1861 and is probably endemic to the shallow waters of the East China Sea.

Seven Unrecorded Indigenous Fungi from Mudeungsan National Park in Korea

Fungi act as important decomposers in the forest environment. They recycle essential nutrients, promote plant growth through mycorrhizal relationships, and act as food for small animals. Samples of 265 indigenous fungal species were collected from Mudeungsan National Park in 2020. These species were identified based on morphological, molecular, and phylogenetic analyses using the internal transcribed spacer (ITS), nuclear large subunit rRNA (LSU), and RNA polymerase II second largest subunit (rpb2) regions. Subsequently, seven species were identified as unrecorded species in Korea: Cordyceps cicadae, Dentocorticium bicolor, Hymenochaete nanospora, Physisporinus crataegi, Rigidoporus piceicola, Russula raoultii, and Scutellinia crinita. This study reveals their detailed macro- and microscopic morphological characteristics with phylogenetic trees to report them as unrecorded species in Korea.

Integrative Taxonomy Reveals Molicola uncinatus and Gymnorhynchus gigas (Cestoda: Trypanorhyncha) Coinfection in the Atlantic Pomfret Brama brama From the Mediterranean Sea, With Notes on the Phylogenetic Position of G. gigas Within the Family Gymnorhynchidae.

The cestode family Gymnorhynchidae Dollfus, 1935 (Trypanorhyncha) comprises three genera and six valid species that are typically intestinal parasites of large pelagic sharks. Members of Gymnorhynchidae show a wide geographic distribution and represent a global sanitary concern because as larvae they infect the edible flesh of several commercially important fishes with some species having allergenic potential. Larval Gymnorhynchidae collected from the muscles of the Atlantic pomfret Brama brama from various localities in the Mediterranean Sea were identified and characterized by combining traditional morphology, scanning electronic microscopy, and molecular analyses using newly generated nuclear 18S and 28S rRNA sequences. Overall, 98 larvae were collected from 20 (100%) Atlantic pomfrets (intensity of infection: 4.9; range: 1–12). High-quality sequences were obtained for 54 larvae. Of these, 11 and 43 larvae were identified as Molicola uncinatus and Gymnorhynchus gigas, respectively. The phylogenetic analysis showed the existence of three main clades within Gymnorhynchidae. The first included species of G. gigas and M. uncinatus from the Mediterranean and Atlantic; the second and third major clades included an unidentified species of Molicola from the Indian Ocean and specimens of Gymnorhynchus isuri from the Mediterranean and Atlantic, respectively. Finally, Chimaerarhynchus rougetae was the basal and most diverging taxon. The phylogenetic analysis suggested that G. gigas is more closely related to the members of Molicola. We demonstrated the coinfection of M. uncinatus and G. gigas from all localities studied and extended the intermediate hosts and geographical range of M. uncinatus by including the Atlantic pomfret and the Tyrrhenian and Ionian Seas, respectively. The present results supported the previous proposal that G. gigas and Molicola species should be included in the same genus. Our study demonstrated the usefulness of the integrative taxonomy for the unequivocal recognition of larval trypanorhynch species, resolving the current difficulties in the taxonomy, and elucidating the poorly known ecological and biological aspects of members of Gymnorhynchidae.

Molecular data resolving the systematics of the related Blattellidae genera Symploce, Episymploce, and Blattella (Blattodea: Blaberoidea)

Members of the morphologically and ecologically diverse Blattellidae provide a dilemma: their systematic assignment, whether morphologically similar or different, is uncertain. We pay special attention to several taxa: the morphologically similarEpisymploceBey-Bienko, 1950 andSymploceHebard, 1916, which were strongly disputed because of their extremely similar generic diagnosis in the past century, and one brachypterous species ofBlattellaCaudell, 1903, which can be easily distinguished from other macropterous members, but is at risk of being misassigned to other genera on the basis of morphological characters. We address the phylogeny of Blattellidae using DNA sequences (mitochondrial12S rRNA,16S rRNA,COII, nuclear28S rRNA, histoneH3) from a broad sample of taxa. A new genus (Centrocolumnagen. nov.) and four new species (Centrocolumna ericeasp. nov.,Symploce nigrasp. nov.,Symploce tubercularissp. nov.,Blattella foliolatasp. nov.) are established on the basis of morphological characters combined with the molecular data. The phylogenetic results indicate the relationships ((Episymploce+Blattella) +Centrocolumnagen. nov.) +Symploce. Furthermore, we delimited the taxonomic status of 12 new combinations, which involveCentrocolumnagen. nov.,Episymploce,Symploce, andBlattella.

Expanding the temporal and spatial scales of environmental DNA research with autonomous sampling

AbstractEnvironmental DNA (eDNA) is an emerging and powerful method for use in marine research, conservation, and management, yet time‐ and resource‐intensive protocols limit the scale of implementation. Long‐range autonomous underwater vehicles equipped with autonomous environmental sample processors (LRAUV‐ESPs) provide a new means for scaling up marine eDNA sample collection and processing. Here, we used eDNA metabarcoding of four marker genes (mitochondrial 12S rRNA, bacterial and archaeal 16S rRNA, nuclear 18S rRNA, and mitochondrial COI), which encompass the diversity of marine species from microbes to vertebrates, to demonstrate the efficacy of an LRAUV‐ESP in sampling eDNA and assessing community structure in the Monterey Bay National Marine Sanctuary. The sequencing results from samples that were autonomously collected were comparable with those collected from a ship at similar locations, times, and depths, supporting previous results that found no significant differences using targeted qPCR. This study demonstrates the potential of equipping autonomous underwater vehicles with ESPs to greatly expand the scale of eDNA sample collection and processing and provide much needed information regarding the changing spatial and temporal patterns of marine biodiversity, especially in many data‐poor regions of the world's oceans.

Linguatula serrata in an imported dog in Germany: Single-case or emerging disease?

Linguatula serrata is a worm-like parasite with zoonotic potential that inhabits the nasal cavities of canids. Although most cases of linguatulosis are associated with unspecific and rather mild respiratory symptoms, cases of unusual infestations and severe courses in both animals and humans have been reported. In central and northern Europe, the pathogen used to appear only sporadically, however, within the last few years the number of detections has increased noticeably. In July 2020 an approximately nine-month-old dog, imported from Romania, was presented in a veterinary practice in Gotha, central Germany, due to persistent worsening cough. Despite antibiotic treatment the tussis became more severe until the dog expectorated multiple worm-like structures. Three of these specimens were sent to the Institute of Parasitology (Faculty of Veterinary Medicine, University of Leipzig, Leipzig) for morphological and genetic species identification. The latter was based on a 1000-bp fragment of the mitochondrial cytochrome c oxidase subunit I gene (cox1) and the complete nuclear 18S rRNA gene. The dog presented in this study suffered from a severe respiratory impairment caused by worm-like parasites inhabiting its upper respiratory tract. The detected parasites were morphologically identified as female specimens of the so-called tongue-worm L. serrata, which was confirmed by pairwise alignment and phylogenetic analysis of the produced sequences. We report an unusually severe case of L. serrata infection in an imported dog and discuss the spread of this potentially dangerous parasite in central and northern Europe.

Integrative Redescription of the Minibiotus intermedius (Plate, 1888)—The Type Species of the Genus Minibiotus R.O. Schuster, 1980

In the present study, we used the integrative taxonomy approach to redescribe Minibiotus intermedius based on the newly found topotypic population in Marburg (Germany). As the original type material is not available, we designate a neotype to stabilize the taxonomy of the genus Minibiotus. Obtained mitochondrial COI barcode sequence and nuclear markers, i.e., 18S rRNA and 28S rRNA of M. intermedius from the neotype locality, were unique and distinct from those deposited in GenBank. In the first redescription of M. intermedius, only four specimens and no eggs from the neotype locality were analyzed. Moreover, genetic analyses were not conducted and barcodes were not available. Therefore, the present study, by establishing the neotype and providing integrative data on the neotype population, helps to better define the Minibiotus taxonomy and prevents further misunderstandings in the future.

Phylogeny, biogeography and classification of Teletisoptera (Blattaria: Isoptera)

AbstractTermites are social cockroaches distributed throughout warm temperate and tropical ecosystems. The ancestor of modern termites roamed the earth during the early Cretaceous, suggesting that both vicariance and overseas dispersal may have shaped the distribution of early diverging termites. We investigate the historical biogeography of three early diverging termite families –Stolotermitidae, Hodotermitidae and Archotermopsidae (clade Teletisoptera) – using the nuclear rRNA genes and mitochondrial genomes of 27 samples. Our analyses confirm the monophyly of Teletisoptera, with Stolotermitidae diverging from Hodotermitidae + Archotermopsidae approximately 100 Ma. Although Hodotermitidae are monophyletic, our results demonstrate the paraphyly of Archotermopsidae. Phylogenetic analyses indicate that the timing of divergence among the main lineages of Hodotermitidae + Archotermopsidae are compatible with vicariance. In the Stolotermitidae, however, the common ancestors of modern Porotermes Hagen and Stolotermes Hagen are roughly as old as 20 and 35 Ma, respectively, indicating that the presence of these genera in South America, Africa and Australia involved over‐water dispersals. Overall, our results suggest that early diverging termite lineages acquired their current distribution through a combination of over‐water dispersals and dispersal via land bridges. We clarify the classification by resolving the paraphyly of Archotermopsidae, restricting the family to Archotermopsis Desneux and Zootermopsis Emerson and elevating Hodotermopsinae (Hodotermopsis Holmgren) as Hodotermopsidae (status novum).

Nuclear and Mitochondrial SSU rRNA Genes Reveal Hidden Diversity of Haptophrya Endosymbionts in Freshwater Planarians and Challenge Their Traditional Classification in Astomatia.

Like many other aquatic animals, freshwater planarians have also become partners of symbiotic ciliates from the class Oligohymenophorea. In the present study, we explored the hidden diversity and addressed the questionable systematic position of mouthless obligatory gut endosymbionts of freshwater planarians, using the nuclear and mitochondrial SSU rRNA genes. Although all isolated ciliates morphologically corresponded to a single species, molecular analyses suggested the existence of three genetically distinct entities: Haptophrya planariarum, Haptophrya dugesiarum nov. spec., and Haptophrya schmidtearum nov. spec. The two former species share the same planarian host, which indicates a speciation model involving one duplication event without host switching. Such a diversification pattern was recognized also in astome ciliates inhabiting megascolecid and glossoscolecid earthworms. The present multi-gene phylogenies along with the secondary structure of the mitochondrial 16S rRNA molecule, however, challenge the traditional classification of Haptophrya within the subclass Astomatia. Haptophrya very likely evolved from an orphan scuticociliate lineage by the loss of oral apparatus and by the transformation of the thigmotactic field into an adhesive sucker. Since astomy evolved multiple times independently within the Oligohymenophorea, the loss of cell mouth cannot be used as a sole argument for the assignment of Haptophrya to the Astomatia anymore.

Molecular insights into the population structure and haplotype network of Theileria annulata based on the small-subunit ribosomal RNA (18S rRNA) gene.

The present study was conducted to elucidate the population genetic diversity and haplotype network of Theileria annulata based on all available nearly complete 18S rRNA gene sequences in the GenBank™. In total, 52 sequences of the nuclear 18S rRNA gene used to assess the relationship of T. annulata with their country of origin identified 34 haplotypes. Haplotype 4 was widespread, occurring in India, China, Turkey and Iran, while the remaining haplotypes were singleton and unique to one country. Haplotype 4 displayed numerous single haplotypes around it and the stellate shape of the network suggested a rapid population expansion. India exhibited the largest number of haplotypes (h=25) followed by Turkey (h=6), China (h=4), and Iran and Italy (h=1). No geographical clustering of haplotypes was recorded. Nucleotide diversity was the highest in the Turkish followed by the Indian and Chinese populations. Similarly, haplotype diversity was the highest in China followed by Turkey, and the lowest in India. The overall dataset exhibited a low nucleotide diversity (0.00253±0.00035), but high haplotype diversity (0.917±0.034). It suggested the presence of only minor differences (01-11 nucleotide) between haplotypes which was also evident from the haplotype network. A high level of genetic diversity was documented within the Indian, Chinese and Turkish populations of T. annulata, whereas little genetic differentiation was noticed among these populations with a very high level of gene flow. Analysis of molecular variance (AMOVA) of T. annulata sequences revealed higher genetic variation within countries (83.58%) as compared to the variation among countries (16.42%). Neutrality indices, viz., Tajima's D, Fu and Li's F, Fu's Fs, and R2, along with the unimodal mismatch distributions demonstrated a recent population expansion of T. annulata in India and the overall dataset. However, the non-significant values of Tajima's D, Fu and Li's F, and Fu's Fs for the Chinese population along with a bimodal mismatch distribution signified a constant population size. For the Turkish population, the neutrality and mismatch distribution tests either indicated a constant or a slight increase in population size. The present study provides novel insights into the population genetics and haplotype network of T. annulata based on the 18S rRNA gene for the first time.

Diversification of the phytophagous lineages of true bugs (Insecta: Hemiptera: Heteroptera) shortly after that of the flowering plants.

More than 95% of phytophagous true bug (Hemiptera: Heteroptera) species belong to four superfamilies: Miroidea (Cimicomorpha), Pentatomoidea, Coreoidea, and Lygaeoidea (all Pentatomomorpha). These iconic groups of highly diverse, overwhelmingly phytophagous insects include several economically prominent agricultural and silvicultural pest species, though their evolutionary history has not yet been well resolved. In particular, superfamily- and family-level phylogenetic relationships of these four lineages have remained controversial, and the divergence times of some crucial nodes for phytophagous true bugs have hitherto been little known, which hampers a better understanding of the evolutionary processes and patterns of phytophagous insects. In the present study, we used 150 species and concatenated nuclear and mitochondrial protein-coding genes and rRNA genes to infer the phylogenetic relationships within the Terheteroptera (Cimicomorpha + Pentatomomorpha) and estimated their divergence times. Our results support the monophyly of Cimicomorpha, Pentatomomorpha, Miroidea, Pentatomoidea, Pyrrhocoroidea, Coreoidea, and Lygaeoidea. The phylogenetic relationships across phytophagous lineages are largely congruent at deep nodes across the analyses based on different datasets and tree-reconstructing methods with just a few exceptions. Estimated divergence times and ancestral state reconstructions for feeding habit indicate that phytophagous true bugs explosively radiated in the Early Cretaceous-shortly after the angiosperm radiation-with the subsequent diversification of the most speciose clades (Mirinae, Pentatomidae, Coreinae, and Rhyparochromidae) in the Late Cretaceous.

Molecular analysis of five controversial Balkanic species of Allolobophora (sensu lato) Eisen, 1873 (Lumbricidae, Clitellata) with emendation of the genus Cernosvitovia Omodeo, 1956.

Allolobophora (sensu lato) is one of the most controversial genera in the taxonomy of Lumbricidae. Due to its poor definition, this genus is plagued by extensive taxonomic confusion, and its generic composition and internal relationships have remained uncertain, especially in species of the Balkan Peninsula. In this study, we have combined the study of morphological data and molecular phylogenetics based on five genetic markers, regions of the nuclear 28S rRNA and mitochondrial 16S rRNA, 12S rRNA, NADH dehydrogenase (ND1) and cytochrome oxidase C subunit 1 (COI), to delimit the taxonomic status of five controversial Balkanic endemic species, Allolobophora (s.l.) dofleini, Allolobophora (s.l.) serbica, Allolobophora (s.l.) strumicae, Allolobophora (s.l.) paratuleskovi and Allolobophora (s.l.) treskavicensis, sampled in the Kopaonik Mountain. Phylogenetic analyses based on our sampling of these five species recovered a well-supported clade containing the species Allolobophora (s.l.) robusta, Allolobophora (s.l.) mehadiensis mehadiensis, Allolobophora (s.l.) sturanyi dacica, Cernosvitovia rebeli and Cernosvitovia dudichi. Based on these results and previous evidence, the aforementioned Balkanic species are transferred to a redefined Cernosvitovia. We further present a revised list of all species currently included in Cernosvitovia., which includes now 21 species and subspecies taxa, 13 of them newly combined here. Serbiona Mri apkarev, 1988 is considered a junior synonym of Cernosvitovia Omodeo, 1956.

Cyphoderia ampulla (Cyphoderiidae: Rhizaria), a tale of freshwater sailors: The causes and consequences of ecological transitions through the salinity barrier in a family of benthic protists.

The salinity barrier that separates marine and freshwater biomes is probably the most important division in biodiversity on Earth. Those organisms that successfully performed this transition had access to new ecosystems while undergoing changes in selective pressure, which often led to major shifts in diversification rates. While these transitions have been extensively investigated in animals, the tempo, mode, and outcome of crossing the salinity barrier have been scarcely studied in other eukaryotes. Here, we reconstructed the evolutionary history of the species complex Cyphoderia ampulla (Euglyphida: Cercozoa: Rhizaria) based on DNA sequences from the nuclear SSU rRNA gene and the mitochondrial cytochrome oxidase subunit I gene, obtained from publicly available environmental DNA data (GeneBank, EukBank) and isolated organisms. A tree calibrated with euglyphid fossils showed that four independent transitions towards freshwater systems occurred from the mid‐Miocene onwards, coincident with important fluctuations in sea level. Ancestral trait reconstructions indicated that the whole family Cyphoderiidae had a marine origin and suggest that ancestors of the freshwater forms were euryhaline and lived in environments with fluctuating salinity. Diversification rates did not show any obvious increase concomitant with ecological transitions, but morphometric analyses indicated that species increased in size and homogenized their morphology after colonizing the new environments. This suggests adaptation to changes in selective pressure exerted by life in freshwater sediments.

First Report of Leaf Spot Caused by Didymella americana on Cassia nomame in China.

Cassia nomame (Sieb.) Kitagawa is an annual plant in the Leguminousae family. The aerial parts of C. nomame have been used as tonic and diuretic in Korea and Japan (Syed et al. 2019). A leaf spot was observed on the leaves of a 1-year-old C. nomame landrace in Changli County (39.42°N, 119.10°E), Qinhuangdao City, Hebei Province during August to October in 2018. In many fields (n≥3), the disease incidence over 80% in the middle and late stage of plant growth. Symptoms on leaves in one field began with many small, dark necrotic spot lesions. Later, the lesions spread to round-to-oval, slightly sunken in the center, and large necrotic patches with indefinite margins. Finally, lesions coalesced and resulted in defoliation. Lesions were occasionally observed on the pods. Symptoms on the pods were initially small, dark spots and then expanded to large necrotic patches with irregular edges. Symptomatic tissues (n=32) from pods and leaves were cut into 3 to 8 mm2 squares, surface disinfested with 75% ethanol for 10 s, rinsed with sterile distilled water, then placed on potato dextrose agar (PDA) at 28℃. After 3 days, ten isolates with consistent characteristics were obtained with a frequency 52.6%. The isolates on PDA were round, initially pale and had little aerial mycelium, gradually turned olive green and had dense wool-like dense aerial mycelia after 3 days. Conidia were hyaline, smooth, solitary, and elliptical. The conidia measured 5.4 to 8.2 μm × 2.5 to 3.8 μm (n=50), and has two oil bodies positioning at opposite poles. Pigmented chlamydospores were spherical or nearly pear-shaped, and solitary. Black fructifications (pycnidia) were produced profusely on PDA after subculture for 3 days. All the isolates were similar to Didymella sp. in morphology (Aveskamp etal.2009). Choice three isolates YSGUO8 YSGGUO8-a and YSGGUO8-b to be further characterized by sequencing of the internal transcribed spacer (ITS), actin gene, and 28S large subunit of the nuclear rRNA gene (LSU) (Zhang et al. 2017). The sequences of three strains (MK836417 MZ484072 and MZ484073 for ITS, MK837604 MZ593675 and MZ593676 for actin, MK843781 MZ836208 and MZ836207 for LSU, respectively) showed 99% to 100% similarity with Didymella americana K-004 (KY070279 for ITS,KY070285 for LSU), Phoma americana CBS 256.65 (FJ426973 for ITS, FJ426871 for actin, MH870196 for LSU) and P. americana CBS 185.85 (FJ426972 for ITS, FJ426870 for actin, GU237990 for LSU) in GenBank. The fungi were identified as D. americana (formerly P. americana or Peyronellaea americana) on the basis of morphological characteristics and sequence analysis. A pathogenicity test was conducted with three times on 1-year-old C. nomame strain at the 4 to 6 compound leaf stage. Conidia were obtained from 7-day-old PDA cultures grown at 28℃ with a 12-h photoperiod. Koch's postulates were fulfilled by spray inoculating ten healthy young plants with 106conidia per milliliter of D. americana strain YSGUO8, and sterile water as the control. After inoculation, the plants were managed at 28℃, 60% relative humidity and a 12-h photoperiod. After 5 to 8 days, the inoculated leaves developed small and dark spots lesions similar to those observed on the leaves with initial symptoms in the field. The control leaves remained symptomless. The same fungi were re-isolated from infected leaves by morphology observation and sequence analysis, confirming Koch's postulates. D. americana has caused leaves spot on Table Beet in New York (Vaghefi et al. 2016). To our knowledge, this is the first report of D. americana causing leaf spot of C. nomame in China.

The Clam Cyclina sinensis (Gmelin) Phylogeography Study with 28S rRNA Gene and Potential of Nuclear rRNA Genes in Genetic Assessments of Molluscs

The Clam Cyclina sinensis (Gmelin) Phylogeography Study with 28S rRNA Gene and Potential of Nuclear rRNA Genes in Genetic Assessments of Molluscs

A robust approach to estimate relative phytoplankton cell abundances from metagenomes.

Phytoplankton account for >45% of global primary production, and have an enormous impact on aquatic food webs and on the entire Earth System. Their members are found among prokaryotes (cyanobacteria) and multiple eukaryotic lineages containing chloroplasts. Genetic surveys of phytoplankton communities generally consist of PCR amplification of bacterial (16S), nuclear (18S) and/or chloroplastic (16S) rRNA marker genes from DNA extracted from environmental samples. However, our appreciation of phytoplankton abundance or biomass is limited by PCR-amplification biases, rRNA gene copy number variations across taxa, and the fact that rRNA genes do not provide insights into metabolic traits such as photosynthesis. Here, we targeted the photosynthetic gene psbO from metagenomes to circumvent these limitations: the method is PCR-free, and the gene is universally and exclusively present in photosynthetic prokaryotes and eukaryotes, mainly in one copy per genome. We applied and validated this new strategy with the size-fractionated marine samples collected by Tara Oceans, and showed improved correlations with flow cytometry and microscopy than when based on rRNA genes. Furthermore, we revealed unexpected features of the ecology of these ecosystems, such as the high abundance of picocyanobacterial aggregates and symbionts in the ocean, and the decrease in relative abundance of phototrophs towards the larger size classes of marine dinoflagellates. To facilitate the incorporation of psbO in molecular-based surveys, we compiled a curated database of >18,000 unique sequences. Overall, psbO appears to be a promising new gene marker for molecular-based evaluations of entire phytoplankton communities.

The Morphology, Mitogenome, Phylogenetic Position, and Symbiotic Bacteria of a New Species of Sclerolinum (Annelida: Siboglinidae) in the South China Sea

Sclerolinum annulatus n. sp. (Annelida: Siboglinidae) is described based on specimens collected from soft sediment of the Haima cold seep in the South China Sea. Morphologically, S. annulatus n. sp. is distinct in having a tube with transverse rings and a forepart (i.e., anterior region) containing one arched row of elongated plaques on both sides of the dorsal furrow. Genome skimming, assembly, and annotation produced a nearly complete mitogenome of S. annulatus n. sp. with 15,553 bp nucleotides that encodes 13 protein-coding genes, two rRNA, and 22 tRNA. Phylogenetic analyses based on the mitochondrial cytochrome c oxidase I (cox1) gene and a concatenated dataset comprising the mitochondrial cox1 and 16S rRNA genes along with the nuclear 18S rRNA gene both strongly support the placement of S. annulatus n. sp. in the genus SclerolinumSouthward, 1961. Based on cox1, S. annulatus n. sp. is most closely related to an undescribed siboglinid from off Kushiro in Japan (“Pogonophora” sp. Kushiro-SK-2003). Transmission electron microscopy, microbial 16S rRNA amplicon sequencing, phylogenetic reconstruction, and stable isotope analyses together indicate that S. annulatus n. sp. hosts a single phylotype of sulfur-oxidizing endosymbionts.

A description of Dendronotus shpataki sp. nov. (Gastropoda: Nudibranchia) from the Sea of Japan: a contribution of citizen science to marine zoology

The nudibranch genus Dendronotus Alder et Hancock, 1845 is a common component of boreal and arctic ecosystems, which has recently received a considerable attention due to its high cryptic diversity. Here we describe a new species Dendronotus shpataki sp. nov. from the northwestern Sea of Japan, using the material and observations provided by Andrey Shpatak, a local citizen, diver and underwater photographer. We studied morphological features of the new species, including external morphology, coloration, jaw and radular morphology, and configuration of the reproductive system, as well as its ecological traits including possible diet preferences. We obtained DNA sequences and reconstructed the phylogeny by Bayesian Inference and Maximum Likelihood approaches using four molecular markers (mitochondrial COI and 16S rRNA, and nuclear histone H3 and 28S rRNA), and tested the boundaries between the species by calculating the uncorrected p-distances and automatic species delimitation methods ABGD and GMYC. Our results show that D. shpataki sp. nov. differs both morphologically and genetically from all other Dendronotus species. The new species possibly represents a unique example of local endemism, being found in a single locality, while other local Dendronotus species demonstrate wide distribution in the North-West Pacific. We also report on a considerable wearing of the radular teeth during feeding, which is a remarkable case for the Dendronotus.

A description of Dendronotus shpataki sp. nov. (Gastropoda: Nudibranchia) from the Sea of Japan: a contribution of citizen science to marine zoology

The nudibranch genus Dendronotus Alder et Hancock, 1845 is a common component of boreal and arctic ecosystems, which has recently received a considerable attention due to its high cryptic diversity. Here we describe a new species Dendronotus shpataki sp. nov. from the northwestern Sea of Japan, using the material and observations provided by Andrey Shpatak, a local citizen, diver and underwater photographer. We studied morphological features of the new species, including external morphology, coloration, jaw and radular morphology, and configuration of the reproductive system, as well as its ecological traits including possible diet preferences. We obtained DNA sequences and reconstructed the phylogeny by Bayesian Inference and Maximum Likelihood approaches using four molecular markers (mitochondrial COI and 16S rRNA, and nuclear histone H3 and 28S rRNA), and tested the boundaries between the species by calculating the uncorrected p-distances and automatic species delimitation methods ABGD and GMYC. Our results show that D. shpataki sp. nov. differs both morphologically and genetically from all other Dendronotus species. The new species possibly represents a unique example of local endemism, being found in a single locality, while other local Dendronotus species demonstrate wide distribution in the North-West Pacific. We also report on a considerable wearing of the radular teeth during feeding, which is a remarkable case for the Dendronotus.

Review of the genus Palmicultor Williams, 1963 (Hemiptera: Coccomorpha: Pseudococcidae), with evidence of a cryptic species

In this study, molecular and morphological analysis of Palmicultor Williams, 1963 (Hemiptera: Coccomorpha: Pseudococcidae) mealybugs, intercepted on plant material entering California and collected in Florida, provides evidence for the existence of a cryptic species under the taxon currently known as P. palmarum (Ehrhorn, 1916). A characterization and analysis based on three molecular markers (mitochondrial COI 5′ end and COI 3′ end regions and nuclear rRNA 18S) for all four described species and the putative cryptic species is presented. Morphological characters used to diagnose species of Palmicultor are evaluated, and an updated identification key to adult females is presented. The history of interceptions of invasive species of Palmicultor in California is addressed, and new host plant records are reported. Considering the high intraspecific morphological variability within the genus, the molecular markers sequenced here provide a useful tool to confirm species identity during high-risk interceptions of these mealybugs.