Plate pattern clarification of the marine dinophyte Heterocapsa triquetra sensu Stein (Dinophyceae) collected at the Kiel Fjord (Germany).

One of the most common marine dinophytes is a species known as Heterocapsa triquetra. When Stein introduced the taxon Heterocapsa, he formally based the type species H. triquetra on the basionym Glenodinium triquetrum. The latter was described by Ehrenberg and is most likely a species of Kryptoperidinium. In addition to that currently unresolved nomenclatural situation, the thecal plate composition of H. triquetra sensu Stein (1883) was controversial in the past. To clarify the debate, we collected material and established the strain UTKG7 from the Baltic Sea off Kiel (Germany, the same locality as Stein had studied), which was investigated using light and electron microscopy, and whose systematic position was inferred using molecular phylogenetics. The small motile cells (18-26 µm in length) had a biconical through fusiform shape and typically were characterized by a short asymmetrically shaped, horn-like protuberance at the antapex. A large spherical nucleus was located in the episome, whereas a single pyrenoid laid in the lower cingular plane. The predominant plate pattern was identified as apical pore complex (Po, cp?, X), 4', 2a, 6'', 6c, 5s, 5''', 2''''. The triradiate body scales were 254-306 nm in diameter, had 6 ridges radiating from a central spine, 9 peripheral and 3 radiating spines, and 12 peripheral bars as well as a central depression in the basal plate. Our work provides a clarification of morphological characters and a new, validly published name for this important but yet formally undescribed species of Heterocapsa: H. steinii sp. nov.

Contributions to the biodiversity of Vietnam - Results of VIETBIO inventory work and field training in Cuc Phuong National Park.

VIETBIO [Innovative approaches to biodiversity discovery and characterisation in Vietnam] is a bilateral German-Vietnamese research and capacity building project focusing on the development and transfer of new methods and technology towards an integrated biodiversity discovery and monitoring system for Vietnam. Dedicated field training and testing of innovative methodologies were undertaken in Cuc Phuong National Park as part and with support of the project, which led to the new biodiversity data and records made available in this article collection. VIETBIO is a collaboration between the Museum für Naturkunde Berlin - Leibniz Institute for Evolution and Biodiversity Science (MfN), the Botanic Garden and Botanical Museum, Freie Universität Berlin (BGBM) and the Vietnam National Museum of Nature (VNMN), the Institute of Ecology and Biological Resources (IEBR), the Southern Institute of Ecology (SIE), as well as the Institute of Tropical Biology (ITB); all Vietnamese institutions belong to the Vietnam Academy of Science and Technology (VAST). The article collection "VIETBIO" (https://doi.org/10.3897/bdj.coll.63) reports original results of recent biodiversity recording and survey work undertaken in Cuc Phuong National Park, northern Vietnam, under the framework of the VIETBIO project. The collection consist of this "main" cover paper - characterising the study area, the general project approaches and activities, while also giving an extensive overview on previous studies from this area - followed by individual papers for higher taxa as studied during the project. The main purpose is to make primary biodiversity records openly available, including several new and interesting findings for this biodiversity-rich conservation area. All individual data papers with their respective primary records are expected to provide useful baselines for further taxonomic, phylogenetic, ecological and conservation-related studies on the respective taxa and, thus, will be maintained as separate datasets, including separate GUIDs also for further updating.

Centric diatom diversity in the lower part of the Southern Bug river (Ukraine): the transitional zone at Mykolaiv city.

The diversity of centric diatoms is documented for the transitional zone of the lower part of the Southern Bug River (Ukraine) just before entering the Dnipro-Bug Estuary and compared to earlier results from the upstream sampling sites of the same river system. Benthic samples of the following sites were investigated: north of Mykolaiv City (approximately 5 km), in Mykolaiv City (near Varvarivskyi Bridge), and 5 km south of the city. Twenty-four centric diatom taxa belonging to 11 genera were identified, analysed, and documented by scanning electron microscopy (SEM) and light microscopy (LM). Among them, Aulacoseira nivalis is the first report for Ukraine, A. islandica and is the first confirmed record for the studied area since the 1930s. The maximum number of centric diatom taxa found in one station was 21, the minimum 10. Melosira subglobosa was the most common (documented in 57-80% of sites with centric diatoms) and abundant species 7.3-15.7% in relative abundance to all diatom taxa. The discovered diversity of taxa and its comparison with previous results is discussed with regard to the relevance of estuary zones in the research of diatoms.

Exploring Diversity, Taxonomy and Phylogeny of Diatoms (Bacillariophyta) from Marine Habitats. Novel Taxa with Internal Costae.

In many marine littoral and sublittoral benthic habitats, we find small diatoms with few features resolvable with light microscopy (LM) other than internal costae across their valves. While classically those internal costae have defined their identification and classification, the use of electron microscopy and of molecular data have started to reveal the true diversity of unrelated forms and genera (e.g., Anaulus, Eunotogramma, Hustedtiella, or Plagiogramma) which possess these structures. Here we describe the new genus Ambo, in an attempt to clarify some of the polyphyly of taxa with internal costa by formally transferring Anaulus balticus, Anaulus simonsenii, and Plagiogramma tenuissimum as well as Ambo gallaeciae, described here. Related to this, we attempt to document and characterize the genus Anaulus itself, which was formally described by Ehrenberg with an illustration. A search by LM of mica designated by Ehrenberg as the holotype of Anaulus scalaris, the generitype of Anaulus, failed to recover a specimen which adequately describes the genus to the exclusion of other genera with internal costa. We also present morphological and molecular data for Anaulus creticus and suggest a new genus-Ceratanaulus-to reflect the distinct morphological and molecular characters we documented.

Differentiating Iconella from Surirella (Bacillariophyceae): typifying four Ehrenberg names and a preliminary checklist of the African taxa.

To comply with the new phylogeny within the Surirellales as supported by molecular and morphological data, re-evaluations and re-combinations of taxa from and within the genera Surirella, Cymatopleura, and Stenopterobia and with the re-established genus Iconella are necessary. Since the African diatom flora is rich with taxa from these genera, especially Iconella, and the authors have studied these taxa recently, describing also new taxa, a preliminary checklist of African Iconella and Surirella is here presented. 94 names are contained on this list. 57 taxa have been transferred to Iconella; 55 taxa were formerly ranked within Surirella and two taxa within Stenopterobia. 10 taxa have stayed within Surirella and six taxa have been transferred from Cymatopleura to Surirella. 20 Surirella and 1 Stenopterobia names are listed which are either unrevised or unrevisable since morphological data is missing. Four names and taxa described by Ehrenberg are here typified. Two had been transferred to Iconella already: Iconella bifrons (Ehrenb.) Ruck & Nakov and Iconella splendida (Ehrenb.) Ruck & Nakov. Two are re-transferred from Cymatopleura to Surirella: Surirella librile (Ehrenb.) Ehrenb. and Surirella undulata (Ehrenb.) Ehrenb.; both taxa are currently known by their younger synonyms: Cymatopleura solea (Bréb.) W. Smith and Cymatopleura elliptica (Bréb. ex Kützing) W. Smith. Lectotypes for Iconella bifrons, I. splendida, Surirella librile, and S. undulata were designated.

Taxonomic reference libraries for environmental barcoding: a best practice example from diatom research.

DNA barcoding uses a short fragment of a DNA sequence to identify a taxon. After obtaining the target sequence it is compared to reference sequences stored in a database to assign an organism name to it. The quality of data in the reference database is the key to the success of the analysis. In the here presented study, multiple types of data have been combined and critically examined in order to create best practice guidelines for taxonomic reference libraries for environmental barcoding. 70 unialgal diatom strains from Berlin waters have been established and cultured to obtain morphological and molecular data. The strains were sequenced for 18S V4 rDNA (the pre-Barcode for protists) as well as rbcL data, and identified by microscopy. LM and for some strains also SEM pictures were taken and physical vouchers deposited at the BGBM. 37 freshwater taxa from 15 naviculoid diatom genera were identified. Four taxa from the genera Amphora, Mayamaea, Planothidium and Stauroneis are described here as new. Names, molecular, morphological and habitat data as well as additional images of living cells are also available electronically in the AlgaTerra Information System. All reference sequences (or reference barcodes) presented here are linked to voucher specimens in order to provide a complete chain of evidence back to the formal taxonomic literature.

Classification of crucigenoid algae: phylogenetic position of the reinstated genus Lemmermannia, Tetrastrum spp. Crucigenia tetrapedia, and C. lauterbornii (Trebouxiophyceae, Chlorophyta)(1).

The subfamily Crucigenioideae was traditionally classified within the well-characterized family Scenedesmaceae (Chlorophyceae). Several morpho-logical revisions and questionable taxonomic changes hampered the correct classification of crucigenoid species resulting in a high number of synonymous genera. We used a molecular approach to determine the phylogenetic position of several Tetrastrum and Crucigenia species. The molecular results were correlated with morphological and ontogenetic characters. Phylogenetic analyses of the SSU rDNA gene resolved the position of Tetrastrum heteracanthum and T. staurogeniaeforme as a new lineage within the Oocystis clade of the Trebouxiophyceae. Crucigenia tetrapedia, T. triangulare, T. punctatum, and T. komarekii were shown to be closely related to Botryococcus (Trebouxiophyceae) and were transferred to Lemmer-mannia. Crucigenia lauterbornii was not closely related to the other Crucigenia strains, but was recovered within the Chlorella clade of the Trebouxiophyceae.