scholarly journals Morphological variation and phylogeny of Karenia selliformis (Gymnodiniales, Dinophyceae) in an intensive cold-water algal bloom in eastern Hokkaido, Japan in September–November 2021

2021 ◽  
Author(s):  
Mitsunori Iwataki ◽  
Wai Mun Lum ◽  
Koyo Kuwata ◽  
Kazuya Takahashi ◽  
Daichi Arima ◽  
...  
Keyword(s):  
Molecular Phylogeny ◽  
Morphological Variation ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Cold Water ◽  
Morphological Observation ◽  
Water Bloom ◽  
Lsu Rdna ◽  
Rdna Sequences ◽  
Typical Cell

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.

scholarly journals Mapping the Distribution of Cysts from the Toxic Dinoflagellate Cochlodinium polykrikoides in Bloom-Prone Estuaries by a Novel FluorescenceIn SituHybridization Assay

2015 ◽  
Vol 82 (4) ◽  
pp. 1114-1125 ◽  
Author(s):  
Theresa K. Hattenrath-Lehmann ◽  
Yu Zhen ◽  
Ryan B. Wallace ◽  
Ying-Zhong Tang ◽  
Christopher J. Gobler
Keyword(s):  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Large Subunit ◽  
Cross Reactivity ◽  
Epifluorescence Microscopy ◽  
Lsu Rdna ◽  
Cochlodinium Polykrikoides ◽  
Content Type ◽  
Ecosystem Studies ◽  
Resting Cysts

ABSTRACTCochlodinium polykrikoidesis a cosmopolitan dinoflagellate that is notorious for causing fish-killing harmful algal blooms (HABs) across North America and Asia. While recent laboratory and ecosystem studies have definitively demonstrated thatCochlodiniumforms resting cysts that may play a key role in the dynamics of its HABs, uncertainties regarding cyst morphology and detection have prohibited even a rudimentary understanding of the distribution ofC. polykrikoidescysts in coastal ecosystems. Here, we report on the development of a fluorescencein situhybridization (FISH) assay using oligonucleotide probes specific for the large subunit (LSU) ribosomal DNA (rDNA) ofC. polykrikoides. The LSU rDNA-targeted FISH assay was used with epifluorescence microscopy and was iteratively refined to maximize the fluorescent reaction withC. polykrikoidesand minimize cross-reactivity. The final LSU rDNA-targeted FISH assay was found to quantitatively recover cysts made by North American isolates ofC. polykrikoidesbut not cysts formed by other common cyst-forming dinoflagellates. The method was then applied to identify and mapC. polykrikoidescysts across bloom-prone estuaries. Annual cyst and vegetative cell surveys revealed that elevated densities ofC. polykrikoidescysts (>100 cm−3) during the spring of a given year were spatially consistent with regions of dense blooms the prior summer. The identity of cysts in sediments was confirmed via independent amplification ofC. polykrikoidesrDNA. This study mappedC. polykrikoidescysts in a natural marine setting and indicates that the excystment of cysts formed by this harmful alga may play a key role in the development of HABs of this species.

Molecular phylogeny of monogeneans parasitizing African freshwater Cichlidae inferred from LSU rDNA sequences

2010 ◽  
Vol 107 (6) ◽  
pp. 1405-1413 ◽  
Author(s):  
Monika Mendlová ◽  
Antoine Pariselle ◽  
Martina Vyskočilová ◽  
Andrea Šimková
Keyword(s):  
Molecular Phylogeny ◽  
Lsu Rdna ◽  
Rdna Sequences

scholarly journals Molecular Identification and Toxin Analysis of Alexandrium spp. in the Beibu Gulf: First Report of Toxic A. tamiyavanichii in Chinese Coastal Waters

Toxins ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 161
Author(s):  
Yixiao Xu ◽  
Xilin He ◽  
Huiling Li ◽  
Teng Zhang ◽  
Fu Lei ◽  
...  
Keyword(s):  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Phylogenetic Analyses ◽  
Large Subunit ◽  
Small Subunit ◽  
Genetic Distances ◽  
Lsu Rdna ◽  
Beibu Gulf ◽  
Gulf Region ◽  
Paralytic Shellfish Toxins

The frequency of harmful algal blooms (HABs) has increased in China in recent years. Information about harmful dinoflagellates and paralytic shellfish toxins (PSTs) is still limited in China, especially in the Beibu Gulf, where PSTs in shellfish have exceeded food safety guidelines on multiple occasions. To explore the nature of the threat from PSTs in the region, eight Alexandrium strains were isolated from waters of the Beibu Gulf and examined using phylogenetic analyses of large subunit (LSU) rDNA, small subunit (SSU) rDNA, and internal transcribed spacer (ITS) sequences. Their toxin composition profiles were also determined using liquid chromatography-tandem mass spectrometry (LC-MS/MS). All eight strains clustered in the phylogenetic tree with A. pseudogonyaulax, A. affine, and A. tamiyavanichii from other locations, forming three well-resolved groups. The intraspecific genetic distances of the three Alexandrium species were significantly smaller than interspecific genetic distances for Alexandrium species. Beibu Gulf isolates were therefore classified as A. pseudogonyaulax, A. affine, and A. tamiyavanichii. No PSTs were identified in A. pseudogonyaulax, but low levels of gonyautoxins (GTXs) 1 to 5, and saxitoxin (STX) were detected in A. tamiyavanichii (a total of 4.60 fmol/cell). The extremely low level of toxicity is inconsistent with PST detection above regulatory levels on multiple occasions within the Beibu Gulf, suggesting that higher toxicity strains may occur in those waters, but were unsampled. Other explanations including biotransformation of PSTs in shellfish and the presence of other PST-producing algae are also suggested. Understanding the toxicity and phylogeny of Alexandrium species provides foundational data for the protection of public health in the Beibu Gulf region and the mitigation of HAB events.

A molecular phylogeny of the Rhigonematomorpha De Ley & Blaxter, 2002 as inferred from SSU and LSU rDNA sequences

Nematology ◽  
2018 ◽  
Vol 20 (6) ◽  
pp. 547-565
Author(s):  
Hugo H. Mejia-Madrid
Keyword(s):  
Maximum Likelihood ◽  
Molecular Phylogeny ◽  
Bootstrap Support ◽  
Lsu Rdna ◽  
Posterior Probabilities ◽  
Monophyletic Clade ◽  
Bayesian Analyses ◽  
Rdna Sequences ◽  
The Future ◽  
Combined Matrix

Summary A molecular hypothesis of the Infraorder Rhigonematomorpha is presented. The phylogeny recovered using combined SSU and LSU markers suggests that the Rhigonematomorpha is nested within a larger clade that includes Ascaridomorpha, Spiruromorpha and Oxyuridomorpha and is strongly supported by maximum likelihood (ML) bootstrap support values (BS) and Bayesian posterior probabilities (BPP). SSU and LSU ML and Bayesian analyses recovered Rhigonematomorpha as a paraphyletic clade. In the ML and Bayesian analyses of a combined matrix of complete to partial sequences of SSU and LSU, respectively, Rhigonematomorpha is recovered as a monophyletic clade with moderate BPP but low BS. Highly supported BS and BPP of a combined SSU and LSU matrix support a hypothesis of a monophyletic Superfamily Ransomnematoidea that includes the families Carnoyidae, Hethidae, Ransomnematidae plus a Brumptaemilius, Cattiena, Insulanema clade, and a monophyletic Superfamily Rhigonematoidea that probably includes the paraphyletic families Rhigonematidae and Ichthyocephalidae. It is suggested that the future inclusion of more families and genera might help resolve the monophyly of the Infraorder Rhigonematomorpha as advanced here.

scholarly journals Molecular phylogeny of ocelloid-bearing dinoflagellates (Warnowiaceae) as inferred from SSU and LSU rDNA sequences

2009 ◽  
Vol 9 (1) ◽  
pp. 116 ◽  
Author(s):  
Mona Hoppenrath ◽  
Tsvetan R Bachvaroff ◽  
Sara M Handy ◽  
Charles F Delwiche ◽  
Brian S Leander
Keyword(s):  
Molecular Phylogeny ◽  
Lsu Rdna ◽  
Rdna Sequences

National coastal management challenges and needs

Shore & Beach ◽  
2020 ◽  
pp. 34-43
Author(s):  
Nicole Elko ◽  
Tiffany Roberts Briggs
Keyword(s):  
Coastal Management ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Local Community ◽  
Extreme Event ◽  
Technical Information ◽  
Interdisciplinary Approach ◽  
Beach Erosion ◽  
The U.S

In partnership with the U.S. Geological Survey Coastal and Marine Hazards and Resources Program (USGS CMHRP) and the U.S. Coastal Research Program (USCRP), the American Shore and Beach Preservation Association (ASBPA) has identified coastal stakeholders’ top coastal management challenges. Informed by two annual surveys, a multiple-choice online poll was conducted in 2019 to evaluate stakeholders’ most pressing problems and needs, including those they felt most ill-equipped to deal with in their day-to-day duties and which tools they most need to address these challenges. The survey also explored where users find technical information and what is missing. From these results, USGS CMHRP, USCRP, ASBPA, and other partners aim to identify research needs that will inform appropriate investments in useful science, tools, and resources to address today’s most pressing coastal challenges. The 15-question survey yielded 134 complete responses with an 80% completion rate from coastal stakeholders such as local community representatives and their industry consultants, state and federal agency representatives, and academics. Respondents from the East, Gulf, West, and Great Lakes coasts, as well as Alaska and Hawaii, were represented. Overall, the prioritized coastal management challenges identified by the survey were: Deteriorating ecosystems leading to reduced (environmental, recreational, economic, storm buffer) functionality, Increasing storminess due to climate change (i.e. more frequent and intense impacts), Coastal flooding, both Sea level rise and associated flooding (e.g. nuisance flooding, king tides), and Combined effects of rainfall and surge on urban flooding (i.e. episodic, short-term), Chronic beach erosion (i.e. high/increasing long-term erosion rates), and Coastal water quality, including harmful algal blooms (e.g. red tide, sargassum). A careful, systematic, and interdisciplinary approach should direct efforts to identify specific research needed to tackle these challenges. A notable shift in priorities from erosion to water-related challenges was recorded from respondents with organizations initially formed for beachfront management. In addition, affiliation-specific and regional responses varied, such as Floridians concern more with harmful algal blooms than any other human and ecosystem health related challenge. The most common need for additional coastal management tools and strategies related to adaptive coastal management to maintain community resilience and continuous storm barriers (dunes, structures), as the top long-term and extreme event needs, respectively. In response to questions about missing information that agencies can provide, respondents frequently mentioned up-to-date data on coastal systems and solutions to challenges as more important than additional tools.

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