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Author(s):  
Lixia Shang ◽  
Xinyu Zhai ◽  
Wen Tian ◽  
Yuyang Liu ◽  
Yangchun Han ◽  
...  

Over the past several decades, much attention has been focused on the dispersal of aquatic nonindigenous species via ballast tanks of shipping vessels worldwide. The recently reclassified dinoflagellate Pseudocochlodinium profundisulcus (previously identified as Cochlodinium sp., Cochlodinium geminatum, or Polykrikos geminatus) was not reported in China until 2006. However, algal blooming events caused by this organism have been reported almost every year since then in the Pearl River Estuary and its adjacent areas in China. Whether P. profundisulcus is an indigenous or an invasive species has thus become an ecological question of great scientific and practical significance. In this study, we collected the sediments from ballast tanks of ships arriving in the ports of China and North America and characterized dinoflagellate resting cysts via a combined approach. We germinated two dark brownish cysts from the tank of an international ship (Vessel A) arriving at the Jiangyin Port (China) into vegetative cells and identified them as P. profundisulcus by light and scanning electron microscopy and phylogenetic analyses for partial LSU rDNA sequences. We also identified P. profundisulcus cyst from the ballast tank sediment of a ship (Vessel B) arriving in the port of North America via single-cyst PCR and cloning sequencing, which indicated that this species could be transported as resting cyst via ship. Since phylogenetic analyses based on partial LSU rDNA sequences could not differentiate all sequences among our cysts from those deposited in the NCBI database into sub-groups, all populations from China, Australia, Japan, and the original sources from which the cysts in the two vessels arrived in China and North America were carried over appeared to share a very recent common ancestor, and the species may have experienced a worldwide expansion recently. These results indicate that P. profundisulcus cysts may have been extensively transferred to many regions of the world via ships’ ballast tank sediments. While our work provides an exemplary case for both the feasibility and complexity (in tracking the source) of the bio-invasion risk via the transport of live resting cysts by ship’s ballast tanks, it also points out an orientation for future investigation.


2021 ◽  
Vol 12 ◽  
Author(s):  
Patricia Moya ◽  
Arantzazu Molins ◽  
Pavel Škaloud ◽  
Pradeep K. Divakar ◽  
Salvador Chiva ◽  
...  

The worldwide, ecologically relevant lichen-forming genus Parmelia currently includes 41 accepted species, of which the Parmelia sulcata group (PSULgp) and the Parmelia saxatilis group (PSAXgp) have received considerable attention over recent decades; however, phycobiont diversity is poorly known in Parmelia s. lat. Here, we studied the diversity of Trebouxia microalgae associated with 159 thalli collected from 30 locations, including nine Parmelia spp.: P. barrenoae, P. encryptata, P. ernstiae, P. mayi, P. omphalodes, P. saxatilis, P. serrana, P. submontana, and P. sulcata. The mycobionts were studied by carrying out phylogenetic analyses of the nrITS. Microalgae genetic diversity was examined by using both nrITS and LSU rDNA markers. To evaluate putative species boundaries, three DNA species delimitation analyses were performed on Trebouxia and Parmelia. All analyses clustered the mycobionts into two main groups: PSULgp and PSAXgp. Species delimitation identified 13 fungal and 15 algal species-level lineages. To identify patterns in specificity and selectivity, the diversity and abundance of the phycobionts were identified for each Parmelia species. High specificity of each Parmelia group for a given Trebouxia clade was observed; PSULgp associated only with clade I and PSAXgp with clade S. However, the degree of specificity is different within each group, since the PSAXgp mycobionts were less specific and associated with 12 Trebouxia spp., meanwhile those of PSULgp interacted only with three Trebouxia spp. Variation-partitioning analyses were conducted to detect the relative contributions of climate, geography, and symbiotic partner to phycobiont and mycobiont distribution patterns. Both analyses explained unexpectedly high portions of variability (99 and 98%) and revealed strong correlations between the fungal and algal diversity. Network analysis discriminated seven ecological clusters. Even though climatic conditions explained the largest proportion of the variation among these clusters, they seemed to show indifference relative to climatic parameters. However, the cluster formed by P. saxatilis A/P. saxatilis B/Trebouxia sp. 2/Trebouxia sp. S02/Trebouxia sp. 3A was identified to prefer cold-temperate as well as humid summer environments.


2021 ◽  
Author(s):  
Mitsunori Iwataki ◽  
Wai Mun Lum ◽  
Koyo Kuwata ◽  
Kazuya Takahashi ◽  
Daichi Arima ◽  
...  

Harmful algal blooms responsible for mass mortalities of marine organisms have so far been rare in Hokkaido, northern Japan, although fish killing blooms have been frequently reported from western Japanese coasts. In September–November 2021, a huge and prolonged cold-water bloom occurred along the Pacific coast of eastern Hokkaido, Japan, and was associated with intensive mortalities of sea urchin, fish, octopus, shellfish, etc. In this study, morphology and phylogeny of the dominant and co-occurred unarmored dinoflagellates of the Kareniaceae in the bloom were examined by using light microscopy, scanning electron microscopy and molecular phylogeny inferred from ITS and LSU rDNA (D1–D3) sequences. Morphological observation and molecular phylogeny showed that the dominant species was Karenia selliformis, with co-occurrences of other kareniacean dinoflagellates, Kr. longicanalis, Kr. mikimotoi, Karlodinium sp., Takayama cf. acrotrocha, Takayama tuberculata and Takayama sp. The typical cell forms of K. selliformis in the bloom were discoid, dorsoventrally flattened, and larger than the cell sizes in previous reports, 35.3–43.6 (39.4±2.1) µm in length. Transparent cells of Kr. selliformis lacking or having several shrunken chloroplasts and oil droplets were also found. Cells of Kr. selliformis had morphological variation, but the species could be distinguished from other co-occurred Karenia species by its numerous (46–105) and small granular (2.9–4.6 µm in diameter) chloroplasts and the nucleus positioned in the hypocone. Cell density of Kr. selliformis exceeding 100 cells/mL was recorded in the range of temperature 9.8–17.6°C. The rDNA sequences determined from Kr. selliformis in the blooms of Hokkaido, Japan in 2021 were identical to those from another bloom in Kamchatka, Russia in 2020.


ALGAE ◽  
2021 ◽  
Vol 36 (4) ◽  
pp. 299-314
Author(s):  
Sang Ah Park ◽  
Hae Jin Jeong ◽  
Jin Hee Ok ◽  
Hee Chang Kang ◽  
Ji Hyun You ◽  
...  

Some species in the dinoflagellate genus Alexandrium are bioluminescent. Of the 33 formally described Alexandrium species, the bioluminescence capability of only nine species have been tested, and eight have been reported to be bioluminescent. The present study investigated the bioluminescence capability of seven Alexandrium species that had not been tested. Alexandrium mediterraneum, A. pohangense, and A. tamutum were bioluminescent, but A. andersonii, A. hiranoi, A. insuetum, and A. pseudogonyaulax were not. We also measured the bioluminescent intensity of A. affine, A. fraterculus, A. mediterraneum, A. ostenfeldii, A. pacificum, A. pohangense, A. tamarense, and A. tamutum. The mean 200-second-integrated bioluminescence intensity per cell ranged from 0.02 to 32.2 × 104 relative luminescence unit per cell (RLU cell-1), and the mean maximum bioluminescence intensity per cell per second (BLMax) ranged from 0.01 to 10.3 × 104 RLU cell-1 s-1-1. BLMax was significantly correlated with the maximum growth rates of Alexandrium species, except for A. tamarense. A phylogenetic tree based on large subunit ribosomal DNA (LSU rDNA) showed that the bioluminescent species A. affine, A. catenella, A. fraterculus, A. mediterraneum, A. pacificum, and A. tamarense formed a large clade. However, the toxicity or mixotrophic capability of these species was split. Thus, their bioluminescence capability in this clade was more consistent than their toxicity or mixotrophic capability. Phylogenetic trees based on LSU rDNA and the luciferase gene of Alexandrium were consistent except for A. pohangense. The results of the present study can provide a basis for understanding the interspecific diversity in bioluminescence of Alexandrium.


2021 ◽  
Vol 12 ◽  
Author(s):  
Minseok Jeong ◽  
Jong Im Kim ◽  
Seung Won Nam ◽  
Woongghi Shin

The genus Spumella, established by Cienkowsky in 1870, is characterized by omnivory, two (rarely three) flagella, a short stick-like structure beneath the flagella, a threadlike stalk, cell division via constriction and cyst formation. Since the first phylogenetic study of Spumella-like flagellates, their paraphyly has consistently been shown, with separation into several genera. More recently, Spumella was carefully investigated using molecular and morphological data to propose seven new species. Classification of this genus and knowledge of its species diversity remain limited because Spumella-like flagellates are extremely difficult to identify based on limited morphological characters. To understand the phylogeny and taxonomy of Spumella, we analyzed molecular and morphological data from 47 strains, including 18 strains isolated from Korean ponds or swamps. Nuclear SSU, ITS and LSU rDNA data were used for maximum likelihood and Bayesian analyses. The molecular data divided the strains into 15 clades, including seven new lineages, each with unique molecular signatures for nuclear SSU rRNA from the E23-2 to E23-5 domains, the spacer between the E23-8 and E23-9 domains of the V4 region and domain 29 of the V5 region. Our results revealed increased species diversity in Spumella. In contrast to the molecular phylogeny results, the taxa showed very similar cell morphologies, suggesting morphological convergence into simple nanoflagellates to enable heterotrophy. Three new species produced stomatocysts in culture. Aspects of stomatocyst morphology, including collar structure, surface ornamentation, and cyst shape, were very useful in differentiating the three species. The general ultrastructure of Spumella bureschii strain Baekdongje012018B8 and S. benthica strain Hwarim032418A5 showed the typical chrysophyte form for the leucoplast, a vestigial chloroplast surrounded by four envelope membranes, supporting the hypothesis that Spumella evolved from a phototroph to a heterotroph via the loss of its photosynthetic ability. Seven new species are proposed: S. benthica, S. communis, S. longicolla, S. oblata, S. rotundata, S. similis, and S. sinechrysos.


2021 ◽  
Vol 20 (10) ◽  
pp. 1275-1296
Author(s):  
Viacheslav Spirin ◽  
Vera Malysheva ◽  
Nathan Schoutteten ◽  
Ilya Viner ◽  
Otto Miettinen ◽  
...  

AbstractTaxonomy of Basidiodendron caesiocinereum complex is revised based on morphological and molecular methods (with the use of nc LSU rDNA, ITS and TEF1 regions). The basidiospore ornamentation is justified as a key morphological character for the species recognition in the group. As redefined here, B. caesiocinereum is an angiosperm-dwelling species with smooth basidiospores. Bourdotia cinerella and B. cinerella var. trachyspora are proved to represent separate species with warted basidiospores; they are reintroduced as Basidiodendron cinerellum and B. trachysporum. Additionally, eight new species related to B. caesiocinereum are described based on material from Eurasia, North America and Africa, and identity of B. spinosum from Oceania is discussed.


2021 ◽  
Author(s):  
Melissa Palacio ◽  
Mauro Westphalen ◽  
Yuan Yuan ◽  
Yingda Wu ◽  
Rosa Mara Borges Da Silveira

Abstract Mycobonia and Pseudofavolus (Polyporales, Basidiomycota) are polyporoid genera with tropical and subtropical distribution. Both genera are morphologically similar in presenting flabelliform to conchate subsessile basidiomata, with a dimitic hyphal system, consisting of clamped generative hyphae and skeleto-binding hyphae that produce large basidiospores with smooth, thin walls. However, while Pseudofavolus species present a poroid hymenophore, in Mycobonia it is stereoid with hyphal pegs that resemble thin teeth. Mycobonia and Pseudofavolus have a controversial taxonomy, and the phylogenetic relationships between their species have yet to be assessed. For this reason, we performed molecular phylogenetic analyses on specimens of Mycobonia and Pseudofavolus from both the Neotropics and Asia, using internal transcribed spacers (ITS), the large subunit of nuclear rDNA (nc LSU rDNA), and also the genes encoding the second largest subunit of RNA polymerase II (RPB2). Furthermore, in order to develop an evolutionary analysis of the hymenophore configuration, we performed stochastic character mapping of ancestral states for the hymenophore type presented in Polyporus s.l. Our study revealed that Pseudofavolus is an artificial group and its species actually nest in a clade within Mycobonia. Therefore, in order to establish a monophyletic group, based upon priority of publication, we re-circunscribed Mycobonia to encompass both stereoid and poroid hymenophore species. Two new combinations are presented from the Neotropics: Mycobonia cucullata and M. miquelii. A new species from tropical Asia, M. yuchengii, is also described. We presente a summary of stochastic mapping of ancestral states estimates of hymenophore type in Polyporus s.l. The ancestral state for Mycobonia clade is estimated to have angular pores.


2021 ◽  
Vol 7 (10) ◽  
pp. 817
Author(s):  
Daniela Isola ◽  
Alessandra Scano ◽  
Germano Orrù ◽  
Francesc Xavier Prenafeta-Boldú ◽  
Laura Zucconi

Human-made hydrocarbon-rich environments are important reservoirs of microorganisms with specific degrading abilities and pathogenic potential. In particular, black fungi are of great interest, but their presence in the environment is frequently underestimated because they are difficult to isolate. In the frame of a biodiversity study from fuel-contaminated sites involving 30 diesel car tanks and 112 fuel pump dispensers (52 diesel and 60 gasoline, respectively), a total of 181 black fungal strains were isolated. The long cold incubation (LCI) of water-suspended samples, followed by plating on Dichloran Rose Bengal Chloramphenicol Agar (DRBC), gave isolation yields up to six times (6.6) higher than those of direct plating on DRBC, and those of enrichment with a phenolic mix. The sequencing of ITS and LSU-rDNA confirmed the dominance of potentially pathogenic fungi from the family Herpotrichiellaceae and Exophiala xenobiotica. Moreover, other opportunistic species were found, including E. opportunistica, E. oligosperma, E. phaeomuriformis, and Rhinocladiella similis. The recurrent presence of E. crusticola, Knufia epidermidis, Aureobasidium melanogenum, Cladosporium spp., and Scolecobasidium spp. was also recorded. Interestingly, 12% of total isolates, corresponding to 50% of taxa found (16/32), represent new species. All the novel taxa in this study were isolated by LCI. These findings suggest that black fungal diversity in hydrocarbon-rich niches remains largely unexplored and that LCI can be an efficient tool for further investigations.


PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11912
Author(s):  
Gita G. Paskerova ◽  
Tatiana S. Miroliubova ◽  
Andrea Valigurová ◽  
Jan Janouškovec ◽  
Magdaléna Kováčiková ◽  
...  

Background Gregarines are a major group of apicomplexan parasites of invertebrates. The gregarine classification is largely incomplete because it relies primarily on light microscopy, while electron microscopy and molecular data in the group are fragmentary and often do not overlap. A key characteristic in gregarine taxonomy is the structure and function of their attachment organelles (AOs). AOs have been commonly classified as “mucrons” or “epimerites” based on their association with other cellular traits such as septation. An alternative proposal focused on the AOs structure, functional role, and developmental fate has recently restricted the terms “mucron” to archigregarines and “epimerite” to eugregarines. Methods Light microscopy and scanning and transmission electron microscopy, molecular phylogenetic analyses of ribosomal RNA genes. Results We obtained the first data on fine morphology of aseptate eugregarines Polyrhabdina pygospionis and Polyrhabdina cf. spionis, the type species. We demonstrate that their AOs differ from the mucron in archigregarines and represent an epimerite structurally resembling that in other eugregarines examined using electron microscopy. We then used the concatenated ribosomal operon DNA sequences (SSU, 5.8S, and LSU rDNA) of P. pygospionis to explore the phylogeny of eugregarines with a resolution superior to SSU rDNA alone. The obtained phylogenies show that the Polyrhabdina clade represents an independent, deep-branching family in the Ancoroidea clade within eugregarines. Combined, these results lend strong support to the hypothesis that the epimerite is a synapomorphic innovation of eugregarines. Based on these findings, we resurrect the family Polyrhabdinidae Kamm, 1922 and erect and diagnose the family Trollidiidae fam. n. within the superfamily Ancoroidea Simdyanov et al., 2017. Additionally, we re-describe the characteristics of P. pygospionis, emend the diagnoses of the genus Polyrhabdina, the family Polyrhabdinidae, and the superfamily Ancoroidea.


2021 ◽  
Author(s):  
Bruno W. Ferreira ◽  
Janaina L. Alves ◽  
Pedro W. Crous ◽  
Robert Barreto

Abstract Korunomyces is a genus including fungi that produce stipitate, profusely branched, multicellular asexual reproductive structures (propagules) on leaves and in culture. Three species have been described in the genus: Korunomyces terminaliae – the type species, K. prostratus and K. zapatensis. No molecular studies have ever been conducted to elucidate the phylogenetic placement of Korunomyces. Recently, DNA sequences were obtained from pure cultures of K. prostratus and K. terminaliae, enabling an elucidation of their taxonomic placement. Isolates of K. prostratus obtained from diseased tissues of Miconia calvescens were observed for the first time to form pycnidial conidiomata in culture. A multi-gene phylogeny, including the large subunit of the nrDNA (nc LSU rDNA), internal transcribed spacer (ITS) region, polymerase II second largest subunit (RPB2) and translation elongation factor 1-α (TEF1), placed K. prostratus and K. terminaliae within Coniella (Schizoparmaceae). As Korunomyces is younger than Coniella, it is reduced to synonymy, and a new name and a new combination are proposed for these two species, namely: Coniella ferreirense nom. nov. and Coniella prostrata comb. nov. An emended description of Coniella to include the occasional formation of distinct and elaborate asexual propagules is also provided.


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