Diatom Research最新文献

{"title":"The type species of the diatom genus Chaetoceros","authors":"W. Kooistra, Wolf-Henning Kusber, D. Hernández-Becerril, M. Montresor, D. Sarno","doi":"10.1080/0269249X.2022.2066182","DOIUrl":"https://doi.org/10.1080/0269249X.2022.2066182","url":null,"abstract":"Chaetoceros is one of the most abundant and diverse diatom genera in the phytoplankton of the world’s oceans. The genus was erected by Ehrenberg in 1844 for two species from the Southern Ocean: C. dichaeta and C. tetrachaeta. According to his description, the former possesses two setae per valve and the latter possesses four. Chaetoceros tetrachaeta, or any species with four setae per valve, has never been reported again. In spite of that, Boyer, in 1927, designated it as the lectotype of the genus. In order to comprehend what Ehrenberg meant with C. dichaeta and C. tetrachaeta we re-examined the type material preserved on mica slides and compared specimens therein with the original descriptions, the drawings published by Ehrenberg in 1872 and notes accompanying the slides. Since no types have ever been designated, we here lectotypify specimens for the two species, guided by Ehrenberg’s coding system explaining their location on the slides. Of the two species, C. dichaeta is well-studied and commonly reported. Its lectotype links unambiguously with those of specimens for which ultrastructural and molecular information has been published. Regarding C. tetrachaeta, our observations confirmed that each valve possesses just two setae, which are robust and thick, typical for the section Chaetoceros. A possible synonym, C. adelianus, occurs in the same region and exhibits the same overall morphology.","PeriodicalId":11199,"journal":{"name":"Diatom Research","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42703421","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Stauroneis terryi D.B. Ward ex T.C. Palmer: a forgotten diatom from northeastern North America","authors":"Marina G. Potapova, Caroline Gallen, Naomi Friedman","doi":"10.1080/0269249X.2022.2078884","DOIUrl":"https://doi.org/10.1080/0269249X.2022.2078884","url":null,"abstract":"Stauroneis terryi D.B. Ward ex T.C. Palmer is a diatom so far reported from only five locations in the states of Connecticut, Massachusetts and Maine, USA, where it was collected in 1890—1911. There were no records of this large and rather conspicuous species in any collections made after 1911 despite the considerable number of diatom surveys and paleolimnological studies conducted in the northeastern USA. We studied material from the type locality of this species to document its morphology with SEM, and screened diatom slides representing recent and subfossil samples collected from 169 lakes in northeastern North America from 1979 to 2017 for the presence of this species. Using both whole-slide scanning and traditional microscopy, we detected S. terryi in 15 lakes in the northeastern USA north of 41° N latitude and in five lakes of Labrador and adjacent Quebec, Canada. In the USA, S. terryi populations have declined since pre-industrial times, although the species is still present in a few lakes with relatively undisturbed watersheds. Our observations demonstrate the value of museum collections for generating data on diatom ecology and biogeography and the need for the development of high-throughput methods of extracting information from diatom slides and images.","PeriodicalId":11199,"journal":{"name":"Diatom Research","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46659347","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Morphology and molecular phylogeny of Amphora baotuensis sp. nov., a new freshwater benthic diatom from a karst spring in China","authors":"Yuhang Li, T. Nagumo, Kuidong Xu","doi":"10.1080/0269249X.2022.2063390","DOIUrl":"https://doi.org/10.1080/0269249X.2022.2063390","url":null,"abstract":"A new freshwater benthic diatom Amphora baotuensis is described from a karst spring in China, based on morphological and molecular phylogenetic data. Based on SSU rRNA and rbcL sequences the molecular phylogeny indicates that this species is closely related to A. copulata (Kützing) Schoeman & Archibald within the Amphora sensu stricto clade. Amphora baotuensis differs from congeners by a combination of morphological features including smaller cell size, a wide, rectangular to fan-shaped dorsal fascia, a well-developed raphe ledge on the ventral side and uniseriate ventral striae.","PeriodicalId":11199,"journal":{"name":"Diatom Research","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46834650","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Seasonal variations of diatoms in a low-latitude mountain lake: a case study from Douhu lake-Southeast China","authors":"Jingkang Wang, Jie Li, Qi Cao, P. Rioual, G. Lei, B. Cai, Y. Zou, Hai Luo, Quanguo Li, Luo Wang","doi":"10.1080/0269249X.2022.2091664","DOIUrl":"https://doi.org/10.1080/0269249X.2022.2091664","url":null,"abstract":"In the scientific literature on diatom ecology whether temperature drives changes in diatom assemblage directly or indirectly remains a subject of debate. In order to clarify the relationship between temperature and diatom assemblage composition, we focused on a region with significant seasonal changes but without a freezing period. From March 2016 to March 2018, sediment trap samples were collected monthly to monitor the seasonal succession of diatoms in Douhu Lake, in subtropical southeast China. The results show that in 2016 the variations in abundance of Aulacoseira granulata and Aulacoseira ambigua followed an obvious seasonal pattern, corresponding to the seasonal variation in water and air temperature. In 2016, the thermophilic taxon A. granulata was dominant in the warm season, and in the cold season its abundance declined, while that of A. ambigua, a taxon better adapted to cooler conditions, increased relatively. In 2017, however, there was no such typical seasonal variation. In the cold season of 2017, A. granulata did not decline and there was no significant increase in the cold-preferring A. ambigua. This was related to the large drop in the lake level associated with human activity (substantial water extraction) that occurred during the winter of 2017, which disturbed the natural seasonal fluctuation in water temperature. Thus, in 2017, while air temperature followed the regular seasonal cycle, lake water temperature did not decrease significantly in winter, which allowed A. granulata to maintain a relatively high abundance in the cold season. From these results and an extensive survey of the literature, we conclude that water temperature, more than the seasonal succession, directly drives the fluctuation in abundance of these two Aulacoseira species.","PeriodicalId":11199,"journal":{"name":"Diatom Research","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41813455","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Gomphotheca marciae (Bacillariophyceae: Bacillariaceae), a new species in a rarely seen genus","authors":"C. Lobban, Gabriella Helene Prelosky","doi":"10.1080/0269249X.2022.2064552","DOIUrl":"https://doi.org/10.1080/0269249X.2022.2064552","url":null,"abstract":"Specimens of an extremely long, heteropolar nitzschioid diatom from mud scraped from mangrove pneumorrhizae on two Micronesian islands were identified as a new species of Gomphotheca. This genus contains two other, rarely seen species, only one of which has been observed with SEM. Our SEM images showed that G. marciae n. sp. is structurally similar to G. sinensis, with very long, heteropolar, cuneate cells with a central keel and internal costate fibulae, and thick, chambered copulae with contrasting external and internal pore patterns. However, the raphe path of G. marciae lacks a central break, conopea are present along each side of the keel, the fibula height is different, pseudosepta are present at both poles, while valve cross section and stria density also differ. We also report the presence of single-walled pleurae.","PeriodicalId":11199,"journal":{"name":"Diatom Research","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47595394","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cocconeis fetscheriana sp. nov. (Bacillariophyta) from streams in California (USA) with reference to the cingulum variability within the placentuloid species complex","authors":"R. Stancheva","doi":"10.1080/0269249X.2022.2074145","DOIUrl":"https://doi.org/10.1080/0269249X.2022.2074145","url":null,"abstract":"A novel diatom species, Cocconeis fetscheriana, is described from streams in California (USA). Detailed light and scanning electron microscopy of its frustules reveal a unique combination of characters. These are a highly variable and often irregular valve outline, rapheless sternum valves with characteristic dumbbell-shaped areolae, forming 7–14 longitudinal rows per hemi-valve, a lanceolate, slightly diagonal sternum separated from the valve apices by up to four areolae, robust closed smooth valvocopula attached to sternum valve mantle by an undulate rim, and raphe valve with distinct submarginal areolae, which always circumradiate the raphe apices. Teratological forms are commonly observed in this novel species and are discussed. Environmental data and morphological comparisons with similar Cocconeis taxa with open valvocopulae are provided. The importance of detailed characterization of the cingulum structure with a particular focus on the rapheless sternum valve valvocopula as diagnostic features in Cocconeis is discussed. Examples of cingulum ultrastructure variability are included from additional undescribed Cocconeis species from another stream in California.","PeriodicalId":11199,"journal":{"name":"Diatom Research","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41722284","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"DNA barcoding reveals a new species of Stephanodiscus Ehrenberg","authors":"Konrad Schultz, T. Hübener, Olivier Jacques, A. Springer, Marcus Frank, Mirko Dressler","doi":"10.1080/0269249X.2022.2078427","DOIUrl":"https://doi.org/10.1080/0269249X.2022.2078427","url":null,"abstract":"The taxonomic situation of the species complex around Stephanodiscus minutulus/parvus is controversial. Insufficient species description and fossil type material contribute to persistent confusion. Håkansson & Kling (1990) described S. binatus as another morphologically similar species in this group. Following the reinvestigation of the type materials of S. minutulus and S. parvus by Houk et al. (2014), it seems that these names are often falsely applied to S. binatus. Monoclonal strains of the S. minutulus/parvus/binatus species complex from European water bodies were established for morphological and molecular analyses. Most of the strains belonged to S. binatus, which seems to be very common in meso- to eutrophic waters in middle Europe. Differing in the barcoding markers, the remaining strains represented a new species, S. neglectus sp. nov., morphologically similar to S. binatus. Stephanodiscus minutulus and S. parvus were not found. Seven strains of S. neglectus sp. nov., seven strains of S. binatus and two strains of Cyclostephanos invisitatus were subjected to detailed morphometric investigation. Four strains of Stephanodiscus hantzschii, Stephanodiscus neoastrea, Cyclostephanos dubius were also included in the molecular analysis. The morphological differential diagnosis of S. neglectus sp. nov. from S. binatus is difficult, but the molecular results show that the species are distinctly different. Using three different loci the distance between the new species and S. binatus equals the distance between S. binatus and S. hantzschii.","PeriodicalId":11199,"journal":{"name":"Diatom Research","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45556832","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Diatoms.org: supporting taxonomists, connecting communities.","authors":"Sarah A Spaulding,&nbsp;Marina G Potapova,&nbsp;Ian W Bishop,&nbsp;Sylvia S Lee,&nbsp;Tim S Gasperak,&nbsp;Elena Jovanoska,&nbsp;Paula C Furey,&nbsp;Mark B Edlund","doi":"10.1080/0269249X.2021.2006790","DOIUrl":"https://doi.org/10.1080/0269249X.2021.2006790","url":null,"abstract":"<p><p>Consistent identification of diatoms is a prerequisite for studying their ecology, biogeography, and successful application as environmental indicators. However, taxonomic consistency among observers has been difficult to achieve, because taxonomic information is scattered across numerous literature sources, presenting challenges to the diatomist. First, literature is often inaccessible because of cost, or its location in journals that are not widely circulated. Second, taxonomic revisions of diatoms are taking place faster than floras can be updated. Finally, taxonomic information is often contradictory across literature sources. These issues can be addressed by developing a content creation community dedicated to making taxonomic, ecological, and image-based data freely available for diatom researchers. Diatoms.org represents such a content curation community, providing open, online access to a vast amount of recent and historical information on North American diatom taxonomy and ecology. The content curation community aggregates existing taxonomic information, creates new content, and provides feedback in the form of corrections and notice of literature with nomenclatural changes. The website not only addresses the needs of experienced diatom scientists for consistent identification, but is also designed to meet users at their level of expertise, including engaging the lay public in the importance of diatom science. The website now contains over 1000 species pages contributed by over 100 content contributors, from students to established scientists. The project began with the intent to provide accurate information on diatom identification, ecology, and distribution using an approach that incorporates engaging design, user feedback, and advanced data access technology. In retrospect, the project that began as an \"extended electronic book\" has emerged not only as a means to support taxonomists, but for practitioners to communicate and collaborate, expanding the size of and benefits to the content curation community. In this paper, we outline the development of diatoms.org, document key elements of the project, examine ongoing challenges, and consider the unexpected emergent properties, including the value of diatoms.org as a source of data. Ultimately, if the field of diatom taxonomy, ecology, and biodiversity is to be relevant, a new generation of taxonomists needs to be trained and employed using new tools. We propose that diatoms.org is in a key position to serve as a hub of training and continuity for the study of diatom biodiversity and aquatic conditions.</p>","PeriodicalId":11199,"journal":{"name":"Diatom Research","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9359083/pdf/nihms-1777221.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10570745","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Morphology of Amphora lunulata A.H. Wachnicka & E.E. Gaiser and its transfer to Seminavis D.G. Mann","authors":"Chenhong Li, Lanyu Tan, Yahui Gao, Xuesong Li, Lin Sun, Junrong Liang, Jun Zhang, Luqiang Huang, Changping Chen","doi":"10.1080/0269249X.2022.2041490","DOIUrl":"https://doi.org/10.1080/0269249X.2022.2041490","url":null,"abstract":"An amphoroid diatom epiphytic on seagrass leaves from Hainan Province, southern China was identified as Amphora lunulata Wachnicka & Gaiser. It is characterized by a semi-elliptical valve with acute apices, ventral striae interrupted at the centre, and an axial area, which is well developed on the dorsal side but narrower at the centre, in accordance with its original description. However, as seen under the scanning electronic microscope, A. lunulata presents a combination of features that is consistent with the description of the genus Seminavis, i.e., slit-like areolae covered by hymenes, terminal fissures hooked toward the dorsal side and unornamented valvocopula. Therefore, we redefined the taxonomic status of Amphora lunulata A.H. Wachnicka & E.E. Gaiser and transferred it to the genus Seminavis. We compared the morphometric characteristics of Seminavis lunulata to those of the original description from Wachnicka & Gaiser (2007) and other taxa in Seminavis, including Seminavis atlantica M. Garcia, Seminavis eulensteinii (Grunow) D.B. Danielidis, K. Ford & D. Kennett, Seminavis heidenii D.G. Mann in D.B. Danielidis & D.G. Mann.","PeriodicalId":11199,"journal":{"name":"Diatom Research","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45012027","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A new monoraphid diatom species from the genus Karayevia sensu lato (Bacillariophyceae: Stauroneidaceae) with remarks on taxonomy and phylogeny of the genus","authors":"N. Tseplik, A. Glushchenko, Y. Maltsev, I. Kuznetsova, S. Genkal, J. Kociolek, M. Kulikovskiy","doi":"10.1080/0269249X.2022.2039780","DOIUrl":"https://doi.org/10.1080/0269249X.2022.2039780","url":null,"abstract":"A new monoraphid diatom, Karayevia chelonica sp. nov., is described from Nha Trang, Vietnam, isolated from marine littoral habitats. Phylogenetic analysis based on partial 18S rDNA and rbcL sequences places this species within the family Stauroneidaceae, and related to other monoraphid species. Karayevia chelonica sp. nov. differs from other species in the genus in stria density and a broad axial area on the rapheless valve. Morphology and taxonomy of the closely related genera Karayevia, Kolbesia and Madinithidium are discussed. Based on morphological characteristics, we conclude that these three genera might represent a single genus, however, further molecular investigation is required to clarify their taxonomic and systematic affinities.","PeriodicalId":11199,"journal":{"name":"Diatom Research","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46187462","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}