(25) Request for a binding decision on whether Geisleria Nitschke (Ascomycota: Strigulaceae) and Geissleria Lange-Bert. & Metzeltin (Bacillariophyceae: Naviculaceae) are sufficiently alike to be confused

P. 647Estudio sobre Diatomeas que se parecen mucho y pueden ser confundidasS

Pseudostaurosira cataractarum comb. nov. (Bacillariophyta): type analysis, ecology and world distribution of a former “centric” diatom

P. 53-63The transfer of Melosira cataractarum Hust. to the genus Pseudostaurosira D.M. Williams & Round is presented based on a detailed analysis of the type material from Java (Malay Archipelago) using light and scanning electron microscopy. The species was initially described as a “centric” diatom within the genus Melosira C. Agardh and was later transferred to the genus Aulacoseira Thwaites. Pseudostaurosira cataractarum (Hust.) C.E. Wetzel, E. Morales & Ector comb. nov. differs from other species of the genus by its smaller size, typical radiate striae arrangement and absence of apical pore fields. We additionally propose the transfer of Fragilaria sopotensis Witkowski & Lange-Bert. to the genus Pseudostaurosira, a species that is morphologically similar to P. cataractarum.S

Response of epilithic diatom communities to environmental gradients in subtropical temperate Brazilian rivers

P. 323-340This work aims to analyse the response of epilithic diatom communities to environmental gradients in subtropical temperate southern Brazilian rivers to contribute to the development of a widely applicable methodology for water-quality monitoring. Samples for physical, chemical and biological determination were collected monthly, from December 2001 to November 2002 and from March 2003 to February 2004, at 9 stations along the rivers Pardo and Pardinho in the hydrographical basin of Rio Pardo, State of Rio Grande do Sul (RS), Brazil. Physical and chemical variables (water temperature, pH, dissolved oxygen, biochemical oxygen demand, chemical oxygen demand, nitrates, nitrites, phosphates and total dissolved solids) and biological variables (epilithic diatom communities) were used as parameters for water-quality assessment. The data matrix was examined by means of a multivariate ordination using Detrended Correspondence Analysis (DCA). In total, 270 taxa were identied to specic or infra-specic levels. The results showed that of all the physical and chemical variables used, the main gradient along the DCA rst axis was eutrophication, which was indicated by its signicant correlation with phosphates ( p < 0.001). Hence, the species’ scores on the DCA axis were used as an operational criterion for indicating their tolerance to eutrophication. From this analysis, the 10 taxa that were the most tolerant to eutrophication were: Cyclotella meneghiniana, Fallacia monoculata, Nitzschia acicularis, N. clausii, N. nana, N. palea, Nitzschia sp., Pinnularia sp., Sellaphora pupula sensu lato and Ulnaria acus. The present study showed that epilithic diatom assemblages reect anthropogenic changes in hydrographic basins in subtropical temperate streams, especially pollution by organic enrichment and eutrophicationS

Fragilaria odeloucaensis sp. nov. (Bacillariophyta, Fragilariaceae) a diatom from temporary streams in southern Portugal

A new species of araphid diatom is described from a temporary stream in southern Portugal, Fragilaria odeloucaensis sp. nov., which belongs to the group of Fragilaria with widely linear to lanceolate valve outline, spaced striae, lacking spines, and with well-developed apical pore fields. The new taxon can be distinguished based on five unique features within this group, the lanceolate valves with capitate apices, the zig-zagged axial area, the central area with squared fascia, the apical pore fields clearly sunken into the valve apices and the heterovalvar frustules (with respect to striae distancing). Ecological features of the type locality and an additional sampling point where the new species was found are given, together with a discussion of the taxonomic position of the new species within Fragilaria, and the approach used herein for the identification of diagnostic features. This approach includes a detailed analysis of the internal and external characteristics of the axial areavirgae-striae complex, central area, apical pore fields and differences among valves of the same frustule, in addition to the traditional valve shape and morphometric features.This work was co-funded by the Science and Management of Intermittent Rivers & Ephemeral Streams (SMIRES) COST Action (CA 15113), http://www.smires.eu, the European Union through the European Regional Development Fund, framed within the Operational Programme Competitiveness and Internationalization, COMPETE 2020 through the ICT project (UID /GEO /04683/2013) with reference POCI -01-0145-FEDE R-007690, and the Agência Portuguesa do Ambiente, APA-000004DFIN .AA LP/2017 integrated within the Operational Program for Sustainability and Efficiency in the Use of Resources 2014-20, POSEUR-03-2013-FC-000001. Co-funding was also provided within the framework of the DIATOMS project (LIST - Luxembourg Institute of Science and Technology)

On some common and new cavum-bearing Planothidium (Bacillariophyta) species from freshwater

[EN] Thirteen Planothidium species are illustrated and discussed in a detailed morphological account based on light and scanning electron microscopy analysis of modern and historic materials related to the names Planothidium rostratum (Østrup) Lange–Bertalot and Planothidium frequentissimum (Lange–Bertalot) Lange–Bertalot. Eight species from freshwater environments in Europe, Asia and South America are proposed as new. All taxa here discussed and illustrated belong to the group of species characterized by the presence of a cavum in the rapheless valve. Additional information concerning their distribution and ecology is briefly commented based on a thorough literature revisionSIThis study was realized in the framework of the project DIATOMS of the Luxembourg Institute of Science and Technology (LIST). We gratefully acknowledge Denise C. Bicudo (Instituto de Botânica de São Paulo, Brazil), Friedel Hinz (Friedrich–Hustedt–Zentrum für Diatomeenforschung, Bremerhaven, Germany), Martin Kelly (Bowburn Consultancy, Durham, UK), Rémy Marcel (AQUABIO, Cournon d’Auvergne, France), Marina Potapova (The Academy of Natural Sciences, Diatom Herbarium, Philadelphia, PA, USA), Jeanne Rigaut (GREBE, Groupe de Recherche et d’Etudes Biologie et Environnement, Lyon, France), Francois Straub (PhycoEco, La Chaux–de–Fonds, Switzerland) and Frank Véry (DREAL Auvergne–Rhône–Alpes, France) for providing materials. The Vlaamse MilieuMaatschappij (VMM, Belgium) is also thanked for providing some of the analysed sample

Response of epilithic diatom communities to environmental gradients in subtropical temperate Brazilian rivers

This work aims to analyse the response of epilithic diatom communities to enviranmental gradients in subtropical temperate southern Brazilian rivers to contribute to the development of a widely applicable methodology for water-quality monitoring. Samples for physical, chemical and biological determination were collected monthly, fram December 2001 to November 2002 and fram March 2003 to February 2004, at 9 stations along the rivers Pardo and Pardinho in the hydrographical basin of Rio Pardo, State of Rio Grande do Sul (RS), Brazil. Physical and chemical variables (water temperature, pH, dissolved oxygen, biochemical oxygen demand, chemical oxygen demand, nitrates, nitrites, phosphates and total dissolved solids) and biological variables (epilithic diatom communities) were used as parameters for water-quality assessment. The data matrix was examined by means of a multivariate ordination using Detrended Correspondence Analysis (DCA). In total, 270 taxa were identified to specific or infra-specific levels. The results showed that of all the physical and chemical variables used, the main gradient along the DCA first axis was eutraphication, which was indicated by its significant correlation with phosphates (p < 0.00l). Hence, the species' scores on the DCA axis were used as an operational criterion for indicating their tolerance to eutrophication. From this analysis, the 10 taxa that were the most tolerant to eutrophication were: Cyclotella meneghiniana, Fallacia monoculata, Nitzschia acicularis, N. clausii, N. nana, N. palea, Nitzschia sp., Pinnularia sp., Sellaphora pupula sensu lato and Ulnaria acuso The present study showed that epilithic diatom assemblages reflect anthropogenic changes in hydrographic basins in subtropical temperate streams, especially pollution by organic enrichment and eutraphication. Key words: Diatoms, eutrophication, biomonitoring, southern Brazilian rivers.Este trabajo pretende analizar la respuesta de la comunidad de diatomeas epilíticas a gradientes ambientales en ríos brasileños templados subtropicales, con el objetivo de contribuir al desarrollo de una metodología ampliamente aplicable para la monitorización de la calidad del agua. Diversas muestras para determinaciones físicas, químicas y biológicas fueron recogidas mensualmente, de diciembre de 2001 a noviembre de 2002, y de marzo de 2003 afebrero de 2004, en nueve esta­ciones de muestre o distribuidas a lo largo de los ríos Pardo y Pardinho, localizados en la Cuenca Hidrográfica del Río Pardo, Estado del Río Grande del Sur; Brasil. Variables físicas y químicas (temperatura del agua, pH, oxígeno disuelto, demanda bioquímica de oxígeno, demanda química de oxígeno, nitratos, nitritos, fosfato y sólidos totales disueltos) y biológicas (co­munidad de diatomeas epilíticas) fueron usadas como parámetros para evaluar la calidad del agua. El conjunto de datos fue analizado por medio de una ordenación multivariante usando el Análisis de Correspondencias sin Tendencias (DCA). En total, 270 taxones fueron identificados a nivel especifico o infra-especifico. Los resultados indicaron que, entre todas las variables físicas y químicas usadas, el principal gradiente establecido a lo largo del primer eje DCA fue la eutrojización, señalada por su correlación significativa con la concentración de fosfatos (p < 0.001). De esta forma, los valores alcanzados por las especies en el primer eje DCA fueron usados como un criterio operativo para indicar su tolerancia a la eutrojización. Los 10 taxones más tolerantes a la eutrojizaciónfueron: Cyc10tella meneghiniana, Fallacia monoculata, Nitzschia acicularis, N. c1ausii, N. nana, N. palea, Nitzschia sp., Pinnularia sp., Sellaphora pupula sensu lato y Ulnaria acuso El presente estudio muestra que la comunidad de diatomeas epilíticas refleja cambios antropogénicos en ríos templados subtropicales de cuencas hidrográjicas, especialmente la contaminación por enriquecimiento orgánico y eutrofización

Morphological reconsideration of the araphid genus Pseudostaurosira (Bacillariophyceae), a revision of Gedaniella, Popovskayella and Serratifera, and a description of a new Nanofrustulum species

Background and aims – As a result of the description of many new species, reanalyses of type material, and information becoming available on valve morphogenesis in small araphid diatoms lacking a rimoportulae, the existing classification scheme at the genus level needs revision. Because morphological information has increased manyfold since the system provided by Williams & Round (1987), it may now be possible to find distinguishing characters in order to produce a more stable and useful framework, encompassing a morphogenetic perspective, which could then guide the placement of newly discovered taxa. This new framework could also be used to help assess the molecular information generated for the group, based on which many new genera are being erected, but perhaps without proper pondering of morphological data. Methods – A thorough review was made of available published information on the ultrastructure of smallcelled araphid diatoms lacking rimoportulae. In addition, image databases were searched, and new light and scanning electron microscopical observations made of some hitherto undescribed species. Key results and conclusions – We provide a table of putative distinguishing features for nine genera (Nanofrustulum, Opephora, Pseudostaurosira, Pseudostaurosiropsis, Punctastriata, Sarcophagodes, Stauroforma, Staurosira and Staurosirella), together with a discussion on their value for discriminating these small diatoms using a morphogenetic perspective. Based on our findings, we amend the genus Pseudostaurosira, establishing wide and short vimines as its most characteristic feature. We use our system in describing a new species from Bolivia, which we place in Nanofrustulum based on its quasifract copulae, the distinguishing trait of the genus. The new species is distinguished from its congeners by its heteropolar valves, apical pore field features, and the multiseriate areolae. We also examine the three genera Popovskayella, Gedaniella, and Serratifera, the latter two recently erected based on molecular information. Since none of these latter genera pass the morphogenetic evaluation we think is essential, we place them in synonymy with other genera and provide the consequent nomenclatural changes. Finally, we make several new combinations in Nanofrustulum, Pseudostaurosira, Sarcophagodes and Staurosirella.Funding for this research was partly provided in the framework of the DIATOMS project (LIST - Luxembourg Institute of Science and Technology). This work was also co-funded by the European Union through the European Regional Development Fund, framed in COMPETE 2020 (Operational Programme Competitiveness and Internationalization), through the ICT project (UID/GEO/04683/2013) with reference POCI01-0145-FEDER-007690 and the Alentejo Observation and Prediction Systems - ALOP project (ALT20-03-0145-FEDER-000004) and the Agencia Portuguesa do Ambiente, APA000004DFIN.AALP/2017 integrated within the Operational Program for Sustainability and Efficiency in the Use of Resources 2014-20, POSEUR-03-2013-FC-000001

Distance Decay of Similarity in Neotropical Diatom Communities

Background The regression of similarity against distance unites several ecological phenomena, and thus provides a highly useful approach for illustrating the spatial turnover across sites. Our aim was to test whether the rates of decay in community similarity differ between diatom growth forms suggested to show different dispersal ability. We hypothesized that the diatom group with lower dispersal ability (i.e. periphyton) would show higher distance decay rates than a group with higher dispersal ability (i.e. plankton). Methods/Principal findings Periphyton and phytoplankton samples were gathered at sites distributed over an area of approximately 800 km length in the Negro River, Amazon basin, Brazil, South America (3°08′00″S; 59°54′30″W). Distance decay relationships were then estimated using distance-based regressions, and the coefficients of these regressions were compared among the groups with different dispersal abilities to assess our predictions. We found evidence that different tributaries and reaches of the Negro River harbor different diatom communities. As expected, the rates of distance decay in community similarity were higher for periphyton than for phytoplankton indicating the lower dispersal ability of periphytic taxa. Conclusions/Significance Our study demonstrates that the comparison of distance decay relationships among taxa with similar ecological requirements, but with different growth form and thus dispersal ability provides a sound approach to evaluate the effects of dispersal ability on beta diversity patterns. Our results are also in line with the growing body of evidence indicating that microorganisms exhibit biogeographic patterns. Finally, we underscore that clumbing all microbial taxa into one group may be a flawed approach to test whether microbes exhibit biogeographic patterns.Peer reviewe

Unexpected consequences of bombing. Community level response of epiphytic diatoms to environmental stress in a saline bomb crater pond area

The spatial response of epiphytic diatom communities to environmental stress was studied in a moderately saline wetland area located in the plain of Danube-Tisza Interfluve, Hungary. The area is characterised by World War II bomb crater ponds and can be regarded as an excellent ecological model system where the dispersion of species is slightly limited by distance. To study the effect of environmental variables on the communities, canonical correspondence analysis was applied. Salinity, pH, total suspended solids, total phosphorous and depth proved to be significant environmental drivers in this analysis. The ecological status of the ponds was assessed with Ziemann's halobity index, as the trophity-depending metric cannot be applied to these habitats (due to the naturally high phosphorus content). Ponds in "good" ecological status significantly differed from those appertaining to water quality category of "not-good" ecological status considering characteristic of natural astatic soda pans (e.g. salinity, pH, ammonium, total phosphorous concentration, nitrogen:phosphorous ratio and turbidity). The differences between epiphytic diatom communities inhabiting the ponds were detected using non-parametric multidimensional scaling. The samples formed three groups according to the types of ponds ("transparent", "transitional" and "turbid") based on the width of the macrophyte belt around them. Indicator species related to the ecological status of the ponds and diatom communities contributing to the separation of groups of ponds were identified. One of the indicator species differed from species already described. Light and scanning electron microscopy features and phylogenetic analyses based on three genes (18S and 28S rRNA genes, rbcL) proved that it was a new species of Nitzschia genus, closely related to Nitzschia frustulum and Nitzschia inconspicua. Therefore, description of a new species, Nitzschia reskoi Acs, Duleba, C.E.Wetzel & Ector is proposed. We concluded that the increasing abundance of Nitzschia reskoi was a signal of the degradation of the intermittent saline wetlands

Juxtaposing BTE and ATE – on the role of the European insurance industry in funding civil litigation

One of the ways in which legal services are financed, and indeed shaped, is through private insurance arrangement. Two contrasting types of legal expenses insurance contracts (LEI) seem to dominate in Europe: before the event (BTE) and after the event (ATE) legal expenses insurance. Notwithstanding institutional differences between different legal systems, BTE and ATE insurance arrangements may be instrumental if government policy is geared towards strengthening a market-oriented system of financing access to justice for individuals and business. At the same time, emphasizing the role of a private industry as a keeper of the gates to justice raises issues of accountability and transparency, not readily reconcilable with demands of competition. Moreover, multiple actors (clients, lawyers, courts, insurers) are involved, causing behavioural dynamics which are not easily predicted or influenced. Against this background, this paper looks into BTE and ATE arrangements by analysing the particularities of BTE and ATE arrangements currently available in some European jurisdictions and by painting a picture of their respective markets and legal contexts. This allows for some reflection on the performance of BTE and ATE providers as both financiers and keepers. Two issues emerge from the analysis that are worthy of some further reflection. Firstly, there is the problematic long-term sustainability of some ATE products. Secondly, the challenges faced by policymakers that would like to nudge consumers into voluntarily taking out BTE LEI