Determining ecological interactions of key dinoflagellate species using an intensive metabarcoding approach in a semi-closed coastal ecosystem of South Korea.

Marine phytoplankton communities are pivotal in biogeochemical cycles and impact global climate change. However, the dynamics of the dinoflagellate community, its co-occurrence relationship with other eukaryotic plankton communities, and environmental factors remain poorly understood. In this study, we aimed to analyze the temporal changes in the eukaryotic plankton community using a 18S rDNA metabarcoding approach. We performed intensive monitoring for 439 days at intervals of three days during the period from November 2018 to June 2020 (n = 260) in Jangmok Bay Time-series Monitoring Site in South Korea. Among the 16,224 amplicon sequence variants (ASVs) obtained, dinoflagellates were the most abundant in the plankton community (38 % of total relative abundance). The dinoflagellate community was divided into 21 groups via cluster analysis, which showed an annually similar distribution of low-temperature periods. Additionally, we selected 11 taxa that had an occurrence mean exceeding 1 % of the total dinoflagellate abundance, accounting for 93 % of the total dinoflagellate community: namely Heterocapsa rotundata, Gymnodinium sp., Akashiwo sanguinea, Amoebophrya sp., Euduboscquella sp., Spiniferites ramosus, Dissodinium pseudolunula, Sinophysis sp., Karlodinium veneficum, and Katodinium glaucum. The key dinoflagellate species were well represented at temporally variable levels over an entire year. Heterocapsa rotundata was not significantly affected by water temperature, whereas its dynamics were largely influenced by strong predation pressure, competition, and/or the supplementation of food sources. The growth of A. sanguinea was associated with dissolved inorganic phosphorus concentrations, while Euduboscquella sp. showed a significant relationship with D. pseudolunula and K. glaucum, largely representing a positive association that implies possible parasitic mechanisms. This study demonstrated interactions between key dinoflagellate species and the environment, as well as parasites, predators, competitors, and feeders.

Convergent evolution revealed by paraphyly and polyphyly of many taxa of oribatid mites: A molecular approach.

A reliable phylogeny is crucial for understanding the evolution and radiation of animal taxa. Phylogenies based on morphological data may be misleading due to frequent convergent evolution of traits-a problem from which molecular phylogenies suffer less. This may be particularly relevant in oribatid mites, an ancient soil animal taxon with more than 11,000 species, where the classification of species into high-ranking taxa such as superfamilies is equivocal. Here, we present a molecular phylogeny of 317 oribatid, 4 astigmatid and 17 endeostigmatid mite species/taxa based on 18S rDNA sequences. We aimed at testing the validity of the 41 superfamilies of oribatid mites recognized by Norton and Behan-Pelletier (in Krantz and Walter, A manual of Acarology, 3rd ed., Texas Technical University Press, Lubbock, 2009). The results indicate that 17 of the 41 oribatid mite superfamilies are monophyletic but that 18 superfamilies are paraphyletic or polyphyletic (5 superfamilies were only included with one species and Microzetoidea were not included). Our findings point to the importance of convergent evolution in polyphyletic oribatid mite taxa. Convergent evolution and the old age of mites likely resulted in a mosaic-like distribution of morphological characters impeding phylogenetic reconstructions based on morphology, calling for molecular approaches to improve oribatid mite systematics.

Harmonized coexistence of intragenomic variations in diatom Skeletonema strains.

Metabarcoding analysis has been demonstrated to be an effective technology for monitoring diversity and dynamics of phytoplankton including Skeletonema species. Although molecular diversity uncovered in metabarcoding projects has generally been interpreted as sum of interspecies diversity and intraspecies diversity, accumulating evidence suggests that it also harbors unprecedentedly high levels of intra-genomic variations (IGVs). As up to thousands of amplicon sequence variants (ASVs) identified in a typical metabarcoding project can be annotated to be Skeletonema species, we hypothesize that substantial portions of these ASVs are contributed by IGVs. Here, the nature of IGVs in Skeletonema species was quantitatively analyzed by carrying out single-strain metabarcoding analysis of 18S rDNA V4 in 49 strains belonging to seven Skeletonema species. Results showed that each Skeletonema strain harbored a high level of IGVs as expected. While many Skeletonema strains each contained one dominant ASV and a substantial number of ASVs displaying much lower relative abundance, other Skeletonema strains each contained multiple ASVs with comparable or nearly equally abundances. Thus the co-existence of multiple dominant ASVs in a single cell indicated a tug-of-war of these variants in evolution, which may eventually result in harmonized coexistence of multiple dominant ASVs. A total of nine dominant ASVs and 652 non-dominant ASVs were found in 49 strains of seven Skeletonema species, indicating rich interspecies and intraspecies variations, and complex evolution of IGVs in genus of Skeletonema. The results confirmed that the extensive degree of IGVs was the main contributor to the high molecular diversity revealed by metabarcoding analysis. This study highlights the importance of quantitative characterization of IGVs in Skeletonema species for accurate interpretation of species diversity in metabarcoding analysis.

High-Throughput Sequencing Analysis Revealed a Preference for Animal-Based Food in Purple Sea Urchins.

Sea urchins play an important role in marine ecosystems. Owing to limitations in previous research methods, there has been insufficient understanding of the food sources and ecological functional value of purple sea urchins, leading to considerable controversy regarding their functional positioning. We focused on Daya Bay as the research area, utilizing stable isotope technology and high-throughput sequencing of 16S rDNA and 18S rDNA to analyze sea urchins and their potential food sources in stone and algae areas. The results showed that the δ13C range of purple sea urchins in the stone area is -11.42~-8.17‱, and the δ15N range is 9.15~10.31‱. However, in the algal area, the δ13C range is -13.97~-12.44‱, and the δ15N range is 8.75~10.14‱. There was a significant difference in δ13C between the two areas (p < 0.05), but there was no significant difference in δ15N (p > 0.05). The main food source for purple sea urchins in both areas is sediment. The sequencing results of 18S rDNA revealed that, in the algal area, the highest proportion in the sea urchin gut was Molluska (57.37%). In the stone area, the highest proportion was Arthropoda (76.71%). The sequencing results of 16S rDNA revealed that, in the algal area, Bacteroidetes was the dominant group in the sea urchin gut (28.87%), whereas, in the stone area, Proteobacteria was the dominant group (37.83%). Diversity detection revealed a significant difference in the number of gut microbes and eukaryotes between the stone and algal areas (p < 0.05). The results revealed that the main food source of purple sea urchins in both areas is sediment, but the organic nutritional value is greater in the algal area, and the richness of microbiota and eukaryotes in the gut of purple sea urchins in the stone area is greater. These results indicated that purple sea urchins are likely omnivores and that the area where they occur impacts their growth and development. The results of this study provide a theoretical basis for the restoration of wild purple sea urchin resources and the selection of areas for restocking and release.

18S and ITS2 rRNA gene sequence-structure phylogeny of the Phaeophyceae (SAR, Stramenopiles) with special reference to Laminariales.

The phylogeny of brown algae (Phaeophyceae) has undergone extensive changes in the recent past due to regular new scientific insights. We used nuclear 18S rDNA with an extensive dataset, aiming to increase the accuracy and robustness of the reconstructed phylogenetic trees using a simultaneous sequence-structure approach. Individual secondary structures were generated for all 18S rDNA sequences. The sequence-structure information was encoded and used for an automated simultaneous sequence-structure alignment. Neighbor-joining and profile neighbor-joining trees were calculated based on 186 phaeophycean sequence-structure pairs. Additionally, sequence-structure neighbor-joining, maximum parsimony and maximum likelihood trees were reconstructed on a representative subset. Using a similar approach, ITS2 rDNA sequence-structure information was used to reconstruct a neighbor-joining tree including 604 sequence-structure pairs of the Laminariales. Our study results are in significant agreement with previous single marker 18S and ITS2 rDNA analyses. Moreover, the 18S results are in wide agreement with recent multi-marker analyses. The bootstrap support was significantly higher for our sequence-structure analysis in comparison to sequence-only analyses in this study and the available literature. This study supports the simultaneous inclusion of sequence-structure data at least for 18S to obtain more accurate and robust phylogenetic trees compared to sequence-only analyses.

Description, life cycle, and development of the myxozoan Myxobolus rasmusseni n. sp. in fathead minnows, Pimephales promelas: A possible emerging pathogen in southern Alberta, Canada.

Morphological, gene sequence, host tissue tropism, and life cycle characteristics were utilized to describe the myxozoan, Myxobolus rasmusseni n. sp. from fathead minnow, Pimephales promelas, collected from reservoirs in southern Alberta. Results from serial histological sections of whole heads showed that myxospores were contained within irregular-shaped and sized coelozoic capsules (=plasmodia). Clusters of membrane-bound, myxospore-filled plasmodia filled the head cavities of juvenile fathead minnows, leading to the development of large, white, disfiguring lesions in mid to late summer. Bilateral exopthalmia (pop-eye disease) was a common outcome of M. rasmusseni n. sp. development. BLASTn search of a 1974 bp sequence of the 18S rDNA gene isolated from myxospores indicated that M. rasmusseni n. sp. was distinct from other coelozoic and histozoic Myxobolus spp. cataloged in GenBank. 18S rDNA gene sequences from triactinomyxon spores released from the oligochaete Tubifex were 100% identical to sequences from myxospores collected from syntopic fathead minnows. Results from a longitudinal survey of the 2020 cohort of fathead minnows showed that young-of-the-year are exposed at 1-5 mo and that 60-90% of these had developed myxospore-filled lesions approximately one year later. Data regarding potential sources and timing of M. rasmusseni n. sp. emergence in fathead minnow populations are needed.

Integrative taxonomic study of mononchid nematodes from riparian habitats in Bulgaria. I. Genera Mononchus Bastian, 1865 and Coomansus Jairajpuri & Khan, 1977 with the description of Mononchuspseudoaquaticus sp. nov. and a key to the species of Mononchus.

The species diversity of the genera Mononchus Bastian, 1865 and Coomansus Jairajpuri & Khan, 1977 was assessed in a study of the mononchid nematodes from a wide range of riparian habitats in Bulgaria. Four species were identified based on morphological and morphometric data: Coomansusparvus (de Man, 1880), Mononchustruncatus Bastian, 1865, Mononchuspseudoaquaticus sp. nov., and Mononchus sp. The first three species were characterised both morphologically and molecularly (18S and 28S rRNA gene sequences) and the integration of these data and phylogenetic analyses provided support for their distinct species status. This paper provides detailed descriptions, morphometric data for multiple species populations, drawings and photomicrographs, and the first taxonomically verified sequences for C.parvus (n = 6), M.truncatus (sensu stricto) (n = 4) and M.pseudoaquaticus sp. nov. (n = 3). Comparative sequence and phylogenetic analyses suggested that the utility of the 18S rRNA gene for species delimitation is rather limited at least for some species complexes within the genus Mononchus. At the generic and suprageneric level, the 18S and 28S rDNA phylogenies both recovered the three genera represented by two or more species (Mononchus, Mylonchulus, and Parkellus) as monophyletic with strong support, the Mononchidae as paraphyletic, the Anatonchidae as monophyletic, and there was no support for a sister-group relationship between Mylonchulus and Mononchus. A key to the species of Mononchus is provided to facilitate the identification of the currently recognised 31 species.

Taxonomy and phylogeny of three species in Perichaena sensu lato (Myxomycetes = Myxogastria) from China.

After Gulielmina was erected and Ophiotheca was resurrected based on some species originally included in Perichaena (Trichiaceae, Trichiales, Myxomyxetes), some specimens from the Herbarium of Fungi of Nanjing Normal University previously identified as Perichaena species were reexamined from morphological and two-gene (nuclear 18S rDNA and elongation factor-1 alpha) phylogenetic perspectives. In this study, two new myxomycete species, Gulielmina subreticulospora and Ophiotheca dictyospora, are described. Gulielmina subreticulospora shows the following character combination: branched plasmodiocarps, single peridium with circular protrusions in the inner surface, capillitium (2.4-)2.8-3.0(-3.4) µm in diameter, spores (7.4-)8.0-8.5(-9.0) µm in diameter and sub-reticulated. Ophiotheca dictyospora shows the following character combination: sessile sporocarps to short plasmodiocarps, single peridium with a densely irregular network and protrusions in the inner surface, capillitium (2.7-)3.5-5.0(-7.1) µm in diameter, uneven, decorated with spines of uneven size, spores (7.7-)8.2-8.6(-9.4) µm in diameter including obviously complete cristate reticulation with serrated edges, with deep and clear grids. Both new taxa were compared with related species and their genetic isolation was statistically tested. Moreover, a comprehensive morphological description and a detailed figure plate are provided for Perichaena verrucifera, and its phylogenetic position is determined.

Saline mine water influences eukaryote life in shallow groundwater of a tropical sandy stream.

Eukaryotic communities in groundwater may be particularly sensitive to disturbance because they are adapted to stable environmental conditions and often have narrow spatial distributions. Traditional methods for characterising these communities, focussing on groundwater-inhabiting macro- and meiofauna (stygofauna), are challenging because of limited taxonomic knowledge and expertise (particularly in less-explored regions), and the time and expense of morphological identification. The primary objective of this study was to evaluate the vulnerability of eukaryote communities in shallow groundwater to mine water discharge containing elevated concentrations of magnesium (Mg) and sulfate (SO4). The study was undertaken in a shallow sand bed aquifer within a wet-dry tropical setting. The aquifer, featuring a saline mine water gradient primarily composed of elevated Mg and SO4, was sampled from piezometers in the creek channel upstream and downstream of the mine water influence during the dry season when only subsurface water flow was present. Groundwater communities were characterised using both morphological assessments of stygofauna from net samples and environmental DNA (eDNA) targeting the 18S rDNA and COI mtDNA genes. eDNA data revealed significant shifts in community composition in response to mine waters, contrasting with findings from traditional morphological composition data. Changes in communities determined using eDNA data were notably associated with concentrations of SO42-, Mg2+ and Na+, and water levels in the piezometers. This underscores the importance of incorporating molecular approaches in impact assessments, as relying solely on traditional stygofauna sampling methods in similar environments may lead to inaccurate conclusions about the responses of the assemblage to studied impacts.

18S rDNA sequence-structure phylogeny of the eukaryotes simultaneously inferred from sequences and their individual secondary structures.

OBJECTIVE: The eukaryotic tree of life has been subject of numerous studies ever since the nineteenth century, with more supergroups and their sister relations being decoded in the last years. In this study, we reconstructed the phylogeny of eukaryotes using complete 18S rDNA sequences and their individual secondary structures simultaneously. After the sequence-structure data was encoded, it was automatically aligned and analyzed using sequence-only as well as sequence-structure approaches. We present overall neighbor-joining trees of 211 eukaryotes as well as the respective profile neighbor-joining trees, which helped to resolve the basal branching pattern. A manually chosen subset was further inspected using neighbor-joining, maximum parsimony, and maximum likelihood analyses. Additionally, the 75 and 100 percent consensus structures of the subset were predicted. RESULTS: All sequence-structure approaches show improvements compared to the respective sequence-only approaches: the average bootstrap support per node of the sequence-structure profile neighbor-joining analyses with 90.3, was higher than the average bootstrap support of the sequence-only profile neighbor-joining analysis with 73.9. Also, the subset analyses using sequence-structure data were better supported. Furthermore, more subgroups of the supergroups were recovered as monophyletic and sister group relations were much more comparable to results as obtained by multi-marker analyses.

Metabarcoding of protozoa and helminth in black-necked cranes: a high prevalence of parasites and free-living amoebae.

Parasites and free-living amoebae (FLA) are common pathogens that pose threats to wildlife and humans. The black-necked crane (Grus nigricollis) is a near-threatened species and there is a shortage of research on its parasite diversity. Our study aimed to use noninvasive methods to detect intestinal parasites and pathogenic FLA in G. nigricollis using high-throughput sequencing (HTS) based on the 18S rDNA V9 region. A total of 38 fresh fecal samples were collected in Dashanbao, China, during the overwintering period (early-, middle I-, middle II-, and late-winter). Based on the 18S data, eight genera of parasites were identified, including three protozoan parasites: Eimeria sp. (92.1%) was the dominant parasite, followed by Tetratrichomonas sp. (36.8%) and Theileria sp. (2.6%). Five genera of helminths were found: Echinostoma sp. (100%), Posthodiplostomum sp. (50.0%), Euryhelmis sp. (26.3%), Eucoleus sp. (50.0%), and Halomonhystera sp. (2.6%). Additionally, eight genera of FLA were detected, including the known pathogens Acanthamoeba spp. (n = 13) and Allovahlkampfia spp. (n = 3). Specific PCRs were used to further identify the species of some parasites and FLA. Furthermore, the 18S data indicated significant changes in the relative abundance and genus diversity of the protozoan parasites and FLA among the four periods. These results underscore the importance of long-term monitoring of pathogens in black-necked cranes to protect this near-endangered species.

Title: Métabarcoding des protozoaires et des helminthes chez les grues à cou noir : forte prévalence de parasites et d'amibes libres. Abstract: Les parasites et les amibes libres sont des agents pathogènes courants qui constituent une menace pour la faune et les humains. La grue à cou noir (Grus nigricollis) est une espèce quasi menacée et les recherches sur sa diversité parasitaire sont insuffisantes. Notre étude visait à utiliser des méthodes non invasives pour détecter les parasites intestinaux et les amibes libres pathogènes chez G. nigricollis en utilisant le séquençage à haut débit basé sur la région V9 de l'ADNr 18S. Au total, 38 échantillons de matières fécales fraîches ont été collectés à Dashanbao, en Chine, au cours de la période d'hivernage (début, milieu I, milieu II et fin de l'hiver). Sur la base des données 18S, huit genres de parasites ont été identifiés, dont trois parasites protozoaires : Eimeria sp. (92,1 %) était le parasite dominant, suivi de Tetratrichomonas sp. (36,8 %) et Theileria sp. (2,6 %). Cinq genres d'helminthes ont été trouvés : Echinostoma sp. (100 %), Posthodiplostomum sp. (50,0 %), Euryhelmis sp. (26,3 %), Eucoleus sp. (50,0 %) et Halomonhystera sp. (2,6 %). De plus, huit genres d'amibes libres ont été détectés, y compris les agents pathogènes connus Acanthamoeba spp. (n = 13) et Allovahlkampfia spp. (n = 3). Des PCR spécifiques ont été utilisées pour identifier davantage les espèces de certains parasites et amibes libres. En outre, les données 18S ont indiqué des changements significatifs dans l'abondance relative et la diversité des genres des parasites protozoaires et des amibes au cours des quatre périodes. Ces résultats soulignent l'importance de la surveillance à long terme des agents pathogènes chez les grues à cou noir pour protéger cette espèce quasi menacée.

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's 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, an order demanding thorough revisions, notably with 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.

Ubiquitous arbuscular mycorrhizal fungi in the roots of herbaceous understory plants with hyphal degeneration in Colchicaceae and Gentianaceae.

Due to the loss of photosynthetic ability during evolution, some plant species rely on mycorrhizal fungi for their carbon source, and this nutritional strategy is known as mycoheterotrophy. Mycoheterotrophic plants forming Paris-type arbuscular mycorrhizas (AM) exhibit two distinctive mycorrhizal features: degeneration of fungal materials and specialization towards particular fungal lineages. To explore the possibility that some understory AM plants show partial mycoheterotrophy, i.e., both photosynthetic and mycoheterotrophic nutritional strategies, we investigated 13 green herbaceous plant species collected from five Japanese temperate forests. Following microscopic observation, degenerated hyphal coils were observed in four species: two Colchicaceae species, Disporum sessile and Disporum smilacinum, and two Gentianaceae species, Gentiana scabra and Swertia japonica. Through amplicon sequencing, however, we found that all examined plant species exhibited no specificity toward AM fungi. Several AM fungi were consistently found across most sites and all plant species studied. Because previous studies reported the detection of these AM fungi from various tree species in Japanese temperate forests, our findings suggest the presence of ubiquitous AM fungi in forest ecosystems. If the understory plants showing fungal degeneration exhibit partial mycoheterotrophy, they may obtain carbon compounds indirectly from a wide range of surrounding plants utilizing such ubiquitous AM fungi.

High-throughput sequencing and fatty acid profile analyses of the Black Amur bream (Megalobrama terminalis) reveal variation in dietary niche associated with geographic segregation.

Fish dietary niche is a core focus, and it reflects the diversity of resources, habitats, or environments occupied by a species. However, whether geographic segregation among different populations triggers dietary diversification and concomitant fish niche shift remains unknown. In the present study, we selected the Black Amur bream (Megalobrama terminalis) is a migratory fish species that plays an important role in the material transfer and energy cycling of river ecosystems, inhabiting southern China drainage with multiple geographic populations. Here, we utilized the combined analyses of 18S rDNA high-throughput sequencing in fish gut contents and fatty acid (FA) in muscle tissues to evaluate potential spatial patterns of habitat and resource use for M. terminalis in three rivers of southern China. Our results showed that prey items of the Xijiang (XR) population (Pearl River) exhibited the highest species diversity and richness among the three geographic populations. Moreover, diet composition of M. terminalis was affected by spatial differences associated with geographic segregation. Analyses of FA biomarkers indicated that the highest levels of C16:0, C18:3n-3, and C18:2n-6c were found in Wanquan (WS) population (Wanquan River). The XR population exhibited a distinct FA profile characterized by higher amounts of arachidonic acid (ARA) and docosahexaenoic acid (DHA). The Moyang (MY) population (Moyang River) acted as the linkage between WS and XR populations and consisted of middle levels of saturated FAs (SFAs) and polyunsaturated FAs (PUFAs). The XR population displayed a greater FA niche width compared with WS population. Furthermore, we observed a close positive relationship between the niche width and α-diversity indices of dietary resources for FA proflies. Our study provides valued information to develop different conservation strategies among different populations and improve fisheries management for M. terminalis and other endemic species in local rivers.

Description of an intramonocytic haemoparasite, Hepatozoon lainsoni sp. nov. (Apicomplexa: Adeleorina: Hepatozoidae), infecting Ameiva ameiva lizard (Reptilia: Squamata: Teiidae) in northern Brazil.

Haemogregarine (Apicomplexa: Adeleorina) parasites are considered to be the most common and widespread haemoparasites in reptiles. The genus Hepatozoon (Apicomplexa: Adeleorina: Hepatozoidae) can be found parasitizing a broad range of species and, in reptiles, they infect mainly peripheral blood erythrocytes. The present study detected and characterized a haemogregarine isolated from the lizard species, Ameiva ameiva, collected from the municipality of Capanema, Pará state, north Brazil. Blood smears and imprints from lungs, brain, heart, kidney, liver, bone marrow and spleen were observed using light microscopy and the parasite was genetically identified by molecular analysis. Morphological, morphometric and molecular data were obtained. Parasite gamonts were found in 49.5% (55/111) of the blood smears from A. ameiva, and were characterized as oval, averaging 12.0 ± 0.8 × 5.9 ± 0.6 µm2 in size, which displaced the nuclei of parasitized monocytes laterally. Parasite forms resembling immature gamonts were observed in the spleen and bone marrow of the lizards. Furthermore, phylogenetic analyses of 18S rRNA sequences did not reveal gene similarity with other Hepatozoon spp. sequences from reptiles. Thus, morphological and molecular analyses have identified a new species of Hepatozoon parasite, Hepatozoon lainsoni sp. nov., which infects monocytes of the A. ameiva lizard.

New molecular evidence on the members of the genus Ortholinea (Cnidaria, Myxozoa) and the description of Ortholinea hamsiensis n. sp. infecting the urinary bladder of European anchovy Engraulis engrasicolus in the Black Sea.

Members of the genus Ortholinea are among the worldwide distributed myxozoan parasites that mainly infect marine fish. In this study, a new myxosporean species, Ortholinea hamsiensis n. sp., was isolated from the urinary bladder of European anchovy Engraulis engrasicolus collected from the Sinop coasts of the Black Sea. The prevalence and density values of infection were 1.4% and 1­5 individuals in the field of view (1 + ), respectively. Mature myxospores are subspherical with slight tapering down to the less pronounced tip in the frontal view and subspherical in the sutural view. Myxospores measured 9.1 ± 0.25 (8.8­9.9) µm in length, 9.2 ± 0.11 (8.9­9.4) µm in thickness, and 8.4 ± 0.33 (8.2-9.1) µm in width. Two polar capsules equal in size measured 3.1 ± 0.11 (3.0­3.3) µm in length and 2.7 ± 0.11 (2.6­2.9) µm in width. The polar tubule had 3­4 coils. Along with morphological peculiarities, the results of the 18S rDNA also revealed it to be a new species for science compared to the other species of the genus. In this study, another myxosporean species O. gobiusi was also detected in round goby Neogobius melanostomus with a prevalence of infection value of 4.8% and a density of 1­5 individuals in the field of view (1 + ). The present study also provided the first data of 18S rDNA of O. gobiusi from N. melanostomus and type species of the genus O. divergens from Gobius niger and the phylogenetic relationships of these species with other Ortholinea species have been revealed.

Biodiversity of autotrophic euglenids based on the group specific DNA metabarcoding approach.

This study reports a comprehensive analysis of photoautotrophic euglenids' distribution and biodiversity in 16 small water bodies of various types (including fish ponds, field ponds, rural ponds and park ponds) located in three regions of Poland: Masovia, Masuria and Pomerania during a period of three years. By employing a euglenid specific barcode marker and a curated database of V2 18S rDNA sequences it was possible to identify 97.7 % of euglenid reads at species level. A total of 152 species classified in 13 genera were identified. The number of euglenid species found in one pond varied from 40 to 102. The most common species were Euglena agilis and Euglenaria caudata, found in every analysed waterbody. The highest number of observed species belonged to Trachelomonas and Phacus. Certain species exhibited a tendency to coexist, suggesting the presence of distinct species assemblages. Among them, the most distinctive cluster was associated with water bodies located in the Masuria region, characterized also by the greatest species richness, including many very rare species: Euglenaformis chlorophoenicea, Lepocinclis autumnalis, L. marssonii, Trachelomonas eurystoma, T. manschurica, T. mucosa, T. zuberi, T. zuberi var. nepos.

Use of PCR-DGGE-Based Molecular Methods to Analyze Nematode Community Diversity.

DGGE (denaturing gradient gel electrophoresis) is a nucleic acid separation technique applied to the evaluation of microbial biodiversity. This technique is quite rapid and cheap compared to other types of analysis. Here we describe the comparison of nematode communities inhabiting different ecosystems. After an ecologically representative sampling collection and the nematode extraction from soil, nematodes are centrifuged in Eppendorf tubes to facilitate DNA extraction. DNA from the whole community of each type of soil is extracted, amplified with primers for 18 S rDNA and used in DGGE analysis. The profiles of DGGE can be analyzed with appropriate software, and biodiversity indices can be estimated.

Network of Soil Fungi and the Microfauna Community under Diverse Anthropic Disturbances under Chrysopogon zizanioides Planting in the Reservoir.

The reservoir coastal zone is the transitional zone between the terrestrial ecosystem and the aquatic ecosystem. Soil is an essential part of the terrestrial ecosystem and vital for life on Earth. To understand the composition and diversity of the soil eukaryotic microbial community under the background of artificial planting of Chrysopogon zizanioides in various habitats after reservoir construction, including the original habitat (OH), the hydro-fluctuation belt (HB), and the road slope (RS), and to analyze the interaction between the main groups of eukaryotic microorganisms, this study conducted 18S rDNA amplification high-throughput sequencing of the soil eukaryotic microbial community. The study found that the dominant phylum of eukaryotic microorganisms in the three habitats was consistent, but there were significant differences in the community and diversity of eukaryotic microorganisms in the three habitats. The differences in fungal communities between sample sites were greater than those of soil microfauna. Correlation analysis showed that nitrogen, phosphorus, and organic matter were significantly correlated with eukaryotic microbial diversity, with alkaline-hydrolyzed nitrogen and total phosphorus significantly correlated with fungal communities and pH and water content correlated with soil microfauna. Co-occurrence network analysis found that the interactions between fungi and the correlation between fungi and soil microfauna dominated the eukaryotic microbial community, and the interactions between eukaryotic microbes in different habitats were dominated by positive correlations. After the construction of the reservoir, the newly formed hydro-fluctuation belt reduced the types of interrelationships between fungi and microfauna compared to the original habitat. The road slope provided protection of the supporting project for the reservoir construction, although there was also planted vegetation. Eukaryotic microbes declined significantly due to the damage to and loss of the organic layer, and the decline in microfauna was the most significant, resulting in a simple structure of the soil food web, which affects the function and stability of the soil ecosystem.

New insights into the chromosomes of stoneflies: I. Karyotype, C-banding and localization of ribosomal and telomeric DNA markers in Skwalacompacta (McLachlan, 1872) (Polyneoptera, Plecoptera, Perlodidae) from Siberia.

This study provides data on chromosome number (2n♂♀=26), sex determination mechanism (XY♂/XX♀), C-banding pattern, distribution of clusters of telomeric TTAGG repeats and 18S ribosomal DNA in the karyotype of the stonefly Skwalacompacta (McLachlan, 1872). For the first time in the history of stoneflies cytogenetics, we provide photos of the chromosomes of the Plecoptera insects. The karyotype of males and females of S.compacta consists of 12 pairs of autosomes. Three pairs of large autosomes and four pairs of medium-sized autosomes are subacrocentric. The remaining pairs of autosomes are small, with unclear morphology. Pericentromeric C-bands were revealed in all autosomes. The sex chromosomes are also subacrocentric. The short arms of X and Y chromosomes are entirely heterochromatic and are rich in ribosomal DNA sequences. In the X chromosome this arm is larger than in the Y chromosome. It is likely that this arm associated with the nucleolar organizer (NOR). Telomeric DNA (TTAGG)n repeats were detected in the terminal regions of all chromosomes.