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15 pages, 2 tables, 7 figures.-- This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY), The dinoflagellate genus Prorocentrum includes several harmful toxigenic species, predominantly benthic ones. In the past, fast-acting toxicity in mice has been observed in extracts of the epibenthic species P. borbonicum, with the finding of two compounds termed as borbotoxins-A and -B. The presence of palytoxin-like compounds was also suggested from electrophysiological experiments. In the present study, a strain of P. borbonicum was isolated in the continental coast of Colombian Caribbean, in seagrass beds of Thalassia testudinum in Bonito Gordo, Tayrona National Natural Park (PNNT). The morphological and molecular characteristics were consistent with the original and former descriptions for this species. Typical haemolytic activity due to palytoxin was confirmed in P. borbonicum extracts in presence of ouabain, the toxin contents being estimated as 1.9 pg palytoxin equivalents cell-1. HPLC-HRMS analyses of these extracts unambiguously identified the presence of borbotoxins and 42-hidroxy-palytoxin (42-OH-PLTX). This is the first report of palytoxin-like compounds in another dinoflagellate genus than Ostreopsis and the first record of P. borbonicum in Colombia and the Caribbean region, This work was funded by the following entities: the Ministry of Science, Technology and Innovation of Colombia - MINCIENCIAS (COLCIENCIAS), the Marine and Coastal Research Institute “Jose Benito Vives de Andreis” (INVEMAR, Contribution number: 1340) and Environmental and Sustainable Development Ministry (MINAMBIENTE) through BPIN project, the International Atomic Energy Agency (IAEA) through the Research Contract RC#18827 (“Bentox Project”) and the Technical Cooperation projects RLA/7/014 and RLA/7/020, the Spanish national project CCVIEO (CNIEO-CSIC), with additional funds of the Axencia Galega de Innovación (agreement GAIN-IEO), la Universidad Nacional de Colombia-UNAL Sede Caribe (within the Project “Influencia de recursos y reguladores en la abundancia de dinoflagelados bentónicos del Caribe”, Hermes Code: 40410). EA-S was supported by a COLCIENCIAS grant (call No. 727–2015)

14 pages, 8 figures, 1 table.-- Under a Creative Commons license, Alexandrium minutum blooms generally occur in semi-enclosed sites such as estuaries, harbours and lagoons, where enhanced stratification, restricted circulation and accumulation of resting cysts in the sediment set suitable habitat conditions for the proliferation of this paralytic shellfish poisoning toxigenic species. In the Galician Rías Baixas (NW Iberian Peninsula), according to weekly time-series between 1994 and 2020, blooms of A. minutum were recurrent in small, shallow estuarine bays inside the Rías de Vigo and Pontevedra, but rarely detected, and if so at low concentrations, out of these environments. However, from May to July 2018 it developed as usual in the small inner bays but then spread over both Rías (Vigo and Pontevedra) causing discoloured waters during one month and prolonged harvesting closures. Meteorological conditions during that period (rains / runoff higher than climatological averages, sustained temperature increment and oscillating wind pattern –i.e., series of upwelling-relaxation cycles), fostered optimal circumstances for the development of that extensive and massive proliferation: strong vertical stratification and the alternation of retention and dispersion processes. Simulations from a particle tracking model portrayed the observed bloom development phases: onset and development inside a small inner bay; transport within the surface layer, from these sites towards the interior parts of the Ría; and dispersion all over the embayment. Seedbeds with high concentrations of resting cysts were detected several months after the bloom, which may have favoured flourishment of A. minutum in the following two years, markedly in 2020. The present work contributes to the general understanding of the dynamics of harmful algal blooms (HABs), from which surveillance indicators of the state of marine ecosystems and their evolution can be derived. We hypothesize that the intensity and frequency of A. minutum proliferations in the Galician Rías could increase under projected climate trends, This work was funded by the Spanish national project DIANAS (CTM2017-86066-R, MICINN) and CCVIEO (Instituto Español de Oceanografía). PD-T was supported by the Xunta de Galicia program “Talento Senior” (N° contract 03 IN858A 2019 1630129) with additional funds of the Axencia Galega de Innovacion (agreement GAIN-IEO)

The dinoflagellate Alexandrium minutum is responsible for paralytic shellfish poisoning (PSP) episodes in Western Europe, commonly in areas directly affected by significant freshwater inputs, as the Ría de Vigo (NW Spain), a coastal embayment with estuarine influence characterized by seasonal upwelling. Because pronounced environmental short-term changes characterized these ecosystems, tolerance windows for A. minutum against temperature (T) and salinity (S) stress were studied using a factorial approach

10 pages, 5 figures, Un episodio de “marea roja” excepcional tuvo lugar el pasado verano de 2018 en las Rías Baixas gallegas debido a la proliferación de microalgas de la especie Alexandrium minutum Halin, 1960. Estas microalgas son dinoflagelados productores de toxinas responsables del síndrome paralizante (PSP) que se acumulan fundamentalmente en moluscos bivalvos pudiendo causar intoxicaciones graves en humanos. El episodio se prolongó desde finales de junio hasta principios de agosto y afectó tanto a los cultivos en batea como a la extracción de moluscos infaunales. La confluencia de varios factores tanto meteorológicos como ambientales pudiera estar detrás de la aparición de dicho episodio que resultó excepcional tanto por su duración como por su extensión geográfica. El departamento de Microalgas Nocivas del Centro Oceanográfico de Vigo realizó un seguimiento exhaustivo de esta “marea roja” que permitió caracterizar con detalle dicho episodio tóxico en función de parámetros físicos, estudios biológicos (taxonómico, concentraciones celulares, ciclo de vida, quistes, etc.) y de la determinación de toxinas PSP en muestras de microalgas procedentes del medio natural, de cultivos y de diferentes organismos que permitió evaluar la afectación de este episodio sobre la fauna

All characterized members of the ubiquitous genus Acaryochloris share the unique property of containing large amounts of chlorophyll (Chl) d, a pigment exhibiting a red absorption maximum strongly shifted towards infrared compared to Chl a. Chl d is the major pigment in these organisms and is notably bound to antenna proteins structurally similar to those of Prochloron, Prochlorothrix and Prochlorococcus, the only three cyanobacteria known so far to contain mono- or divinyl-Chl a and b as major pigments and to lack phycobilisomes. Here, we describe RCC1774, a strain isolated from the foreshore near Roscof (France). It is phylogenetically related to members of the Acaryochloris genus but completely lacks Chl d. Instead, it possesses monovinyl-Chl a and b at a b/a molar ratio of 0.16, similar to that in Prochloron and Prochlorothrix. It difers from the latter by the presence of phycocyanin and a vestigial allophycocyanin energetically coupled to photosystems. Genome sequencing confrmed the presence of phycobiliprotein and Chl b synthesis genes. Based on its phylogeny, ultrastructural characteristics and unique pigment suite, we describe RCC1774 as a novel species that we name Acaryochloris thomasi. Its very unusual pigment content compared to other Acaryochloris spp. is likely related to its specifc lifestyle.

Three strains of the toxic benthic dinoflagellate Prorocentrum hoffmannianum were isolated in the Canary Islands (north-east Atlantic Ocean, Spain). The identity of the strains was determined by phylogenetic analyses of partial LSU rDNA (D1-D2 regions) but their morphology based on SEM images corresponded to P. maculosum. Their toxin profiles were analyzed by liquid chromatography and high resolution mass spectrometry analysis (LC–HRMS) on cell extracts and culture media. Okadaic acid and three analogs were detected in all strains. Rather, in culture media the detected compounds were variable among strains, two of them being okadaic acid analogs not found on cell extracts. As a result, the taxonomy of the species was revised and P. maculosum is proposed as a junior synonym of P. hoffmannianum whose description is emended.

Harmful algal blooms (HABs) are a natural global phenomena emerging in severity and extent. Incidents have many economic, ecological and human health impacts. Monitoring and providing early warning of toxic HABs are critical for protecting public health. Current monitoring programmes include measuring the number of toxic phytoplankton cells in the water and biotoxin levels in shellfish tissue. As these efforts are demanding and labour intensive, methods which improve the efficiency are essential. This study compares the utilisation of a multitoxin surface plasmon resonance (multitoxin SPR) biosensor with enzyme-linked immunosorbent assay (ELISA) and analytical methods such as high performance liquid chromatography with fluorescence detection (HPLC-FLD) and liquid chromatography–tandem mass spectrometry (LC–MS/MS) for toxic HAB monitoring efforts in Europe. Seawater samples (n = 256) from European waters, collected 2009–2011, were analysed for biotoxins: saxitoxin and analogues, okadaic acid and dinophysistoxins 1/2 (DTX1/DTX2) and domoic acid responsible for paralytic shellfish poisoning (PSP), diarrheic shellfish poisoning (DSP) and amnesic shellfish poisoning (ASP), respectively. Biotoxins were detected mainly in samples from Spain and Ireland. France and Norway appeared to have the lowest number of toxic samples. Both the multitoxin SPR biosensor and the RNA microarray were more sensitive at detecting toxic HABs than standard light microscopy phytoplankton monitoring. Correlations between each of the detection methods were performed with the overall agreement, based on statistical 2 × 2 comparison tables, between each testing platform ranging between 32% and 74% for all three toxin families illustrating that one individual testing method may not be an ideal solution. An efficient early warning monitoring system for the detection of toxic HABs could therefore be achieved by combining both the multitoxin SPR biosensor and RNA microarray., SI

14 páginas, 2 tablas, 8 figuras, Many studies on photoacclimation examine the pigment responses to changes in light intensity, but variations in light climate in the aquatic environment are also related to changes in spectral composition. We have employed a high-performance liquid chromatography method with improved resolution towards chlorophyll c and fucoxanthin-related xanthophylls to examine the pigment composition of Emiliania huxleyi CCMP 370 under different light intensities and spectral qualities. To maintain its photosynthetic performance, E. huxleyi CCMP370 promotes drastic pigment changes that can be either the interconversion of pigments in pools with the same basic chromophoric structure (Fucoxanthin type or chlorophyll c type), or the ex novo synthesis (Diatoxanthin). These changes are linked either to variations in light quality (Fucoxanthin related xanthophylls) or in light intensity (chlorophyll c3/Monovinyl chlorophyll c3, Diadinoxanthin/Diatoxanthin, β,ɛ−carotene/ β,β-carotene). Fucoxanthin and 19′-hexanoyloxyfucoxanthin proportions were highly dependent on spectral conditions. Whereas Fucoxanthin dominated in green and red light, 19′-hexanoyloxyfucoxanthin prevailed under blue spectral conditions. Our results suggest that the huge pigment diversity enhanced the photoacclimative capacities of E. huxleyi to efficiently perform under changing light environments. The ubiquity and success in the global ocean as well as the capacity of E. huxleyi to form large surface blooms might be associated to the plasticity described here, This work is a contribution of Microalgas Nocivas, IEO, Unidad Asociada al IIM (CSIC) and was supported by Xunta de Galicia through project Incite09 402 253PR

Aquatic Sciences Meeting, Aquatic Sciences: Global And Regional Perspectives - North Meets South, 22-27 February 2015, Granada, Spain, The relationships between environmental forcing (hydrographic characteristics of the water column, in situ PAR and major nutrient profiles) and the vertical distribution patterns of in vivo fluorescence and chlorophyll a (Chl a) concentration have been studied along transects of the Malaspina 2010 expedition covering several biogeographic regions in the Indian and Pacific Oceans. Except in the zone of the Equatorial upwelling, a subsurface Chl a maximum (SCM) was generally found at depths between 60 and 150 m. It was typically located at about the 1% light level, in association with the nutriclines and the nitrite maximum. The SCM occurred well below the depth of maximum Brunt-Väisälä frequency in the open Indian Ocean and South Equatorial Pacific, and near or above it in zones strongly influenced by advection (Agulhas, Great Australian Bight). The average proportion of Chl a in the size fraction < 2 micrometers ranged from 60% at surface to 66% at the DCM. The relationship between surface Chl a concentration and integrated Chl a was significant for some geographical regions, but not for the whole data set

Las floraciones de dinoflagelados del género Dinophysis producen toxinas (diarreogénicas y pectenotoxinas) lipofílicas que son acumuladas por los bivalvos filtradores y acarrean prolongadas vedas de extracción. Estas vedas (eventos DSP) se producen cada vez que los niveles de toxinas superan los límite establecidos para salvaguardar la salud pública y constituyen la principal AMENAZA para la producción de bivalvos en la costa Atlántica europea, en particular para el sector mejillonero de Galicia. Las floraciones de D. acuminata y D.acuta son un problema endémico en las Rías gallegas (OPORTUNIDADES). Las dos especies presentan distintos patrones de distribución, perfiles de toxinas y causan impactos específicos en los recursos. La predicción de floraciones (de baja densidad) de Dinophysis, controladas por el clima, constituye la principal herramienta de mitigación, pues permite al sector planificar agendas de recolección y diseñar planes de contingencia. El desarrollo de modelos predictivos específicos requiere un conocimiento sólido de la fisiología así como la cuantificación de la respuesta específica de las especies diana a los procesos ambientales que controlan la dinámica de sus poblaciones. Este desarrollo es especialmente complejo (DEBILIDAD) cuando se aplica a especies mixótrofas, como Dinophysis, que son el tercer eslabón de una cadena mixótrofa: criptofita―ciliado―dinoflagelado. Se dispone de modelos conceptuales sobre la respuesta a corto plazo de D. acuminata y D. acuta al forzamiento meteorológico, patrón de afloramiento y factores biológicos que modulan su crecimiento. No obstante, persisten importantes lagunas de conocimiento sobre el comportamiento nutricional (especificidad de presa ciliada de Dinophysis y de presa criptofita del ciliado, fuentes nitrogenadas), así como sobre el origen de las poblaciones inóculo y los factores que determinan su variabilidad interanual. Con el reciente establecimiento de cultivos de cepas gallegas de las dos especies de Dinophysis y del ciliado Mesodinium rubrum (de Andalucía) se superaron las trabas al desarrollo de experimentos de laboratorio. Éstos, junto con la masa crítica alcanzada de resultados de campañas y programas de seguimiento (FORTALEZA) nos permiten afrontar nuevos retos en la mejora de predicción de floraciones de Dinophysis. Se propone un estudio comparativo sobre interacciones físico-biológicas y autoecología de D. acuminata y D. acuta con el fin de : (1) cuantificar y parametrizar las anomalías en el patrón de afloramiento de invierno y de estratificación estival que propician la iniciación precoz de proliferaciones primaverales de D.acuminata y estivales de D. acuta respectivamente; 2) investigar sus fuentes de nitrógeno y cuantificar la influencia de la luz, temperatura y turbulencia en su balance de crecimiento/producción de toxinas; 3) explorar, con herramientas moleculares, la existencia de ciliados presa distintos que M. rubrum así como diferencias en biodiversidad pico- y nanoplanctónica asociadas al inicio y desarrollo de las dos especies de Dinophysis. Los resultados obtenidos contribuirán a explicar la variabilidad interanual y el reeemplazo de D. acuminata por D acuta en determinados años. Asimismo, ayudarán a explicar la paradoja de su coexistencia ciertos años, pero ocupando distintas capas de la columna agua. El objetivo último es obtener información útil para la mejora de modelos predictivos de cara a una aproximación de oceanografía operacional CGL2013-48861-R

The epibenthic dinoflagellate Ostreopsis is a potentially toxic bloom-forming organism. Ostreopsis spp. have the ability to produce palytoxin-like compounds which have demonstrated to be harmful for both human health and 4benthic invertebrates (sea urchins). This genus often co-occurs with other dinoflagellates (i.e. Coolia, Prorocentrum) but little is known about the potential interactions between these dinoflagellates in the benthic environment. The aim of the present study was to explore the potential inhibitory effects on growth and/or cell behavior by toxic strains of Ostreopsis cf. ovata (VGO 1001) and Ostreopsis sp. (Lanzarote type VGO 1000), on two non-toxin producer dinoflagellates (Coolia monotis and Prorocentrum elegans) isolated from the same geographical area (Canary Islands, NE Atlantic).

Species of the dinoflagellate genus Gambierdiscus are the cause of Ciguatera Fish Poisoning which is very common in tropical areas, mainly in the Pacific Ocean and Caribbean Sea. Until 2008 this disease was not reported in the NE Atlantic Ocean, when human intoxications after consumption of local fish have been reported almost yearly in the Canary Islands. Sampling of tidal ponds on rocky shores of this archipelago has revealed an unexpected diversity of the genus Gambierdiscus in the area. Morphological and phylogenetic studies of culture isolates established the presence of at least three different species: G. excentricus (originally described in the Canaries), G. australes, and a third species soon to be formally characterized, with close characteristics to G. polynesiensis and Gambierdiscus sp. type 4 sensu Xu et al (2014). The evaluation of toxicity in these species was performed by mouse bioassay (MBA) and erythrocyte lyses assay (ELA). Additionally, identification of the CTXs congeners will be conducted using liquid chromatography (LC) coupled with high resolution mass spectrometry (HRMS) analyses. Nevertheless, the link between local Gambierdiscus populations and ciguateric fish has not been unambiguously demonstrated. Future studies should focus more efforts on the phylogeography of Gambierdiscus in the Canaries, the distribution and abundance of their populations, and the characterization of toxin profiles in cultures vs those in local fishes to understand if ciguatoxins are accumulated in Canaries waters or other surrounding areas in the Macaronesian region.

Species of the dinoflagellate genus Gambierdiscus are the cause of Ciguatera Fish Poisoning, common in tropical areas. Nevertheless, until recently this syndrome was not reported in the NE Atlantic Ocean. A new photosynthetic dinoflagellate species, Gambierdiscus silvae sp. nov. is described based on samples taken from tide pools on rocky shores of the Canary Islands (NE Atlantic Ocean). Its mor- phology was studied by light and scanning electron microscopy. The new species is anterioposteriorly compressed, lenticular in shape with an epitheca slightly higher than the hypotheca. It is round in apical view and has a thick smooth theca with many scattered pores. Plate formula is Po, 4 , 0a, 6 , 6c, 6s?, 5 , 0p, 2 . Plate 2 is hatchet-shaped and Plate 2 is very wide and the largest of the hypotheca. Phyloge- nies inferred from the large subunit nuclear rRNA showed that three G. silvae strains clustered in a well supported sister clade to G. polynesiensis, distinct from the other species. G. australes was observed for the first time in the Atlantic, together with G. excentricus already reported from these islands. This work increases the number of Gambierdiscus species described and shows their unexpected diversity in the Canary Islands. 4,1400

Introducción: El diagnóstico definitivo de cáncer de paratiroides es extremadamente difícil, desde el acercamiento clínico hasta el diagnóstico molecular. Se detectó recientemente en pacientes con cáncer de paratirodes un gen supresor de tumor mutado (HRPT2), que codifica para una proteína que participa en el complejo PAF1, la parafibromina. Se ha observado que la expresión de esta proteína está alterada en los casos de cáncer de paratiroides, lo que serviría como método de diagnóstico por inmunohistoquímica, con una sensibilidad y especificidad de 73-96% y 99-100%, respectivamente. Material y Método: Se realizó tinción inmunohistoquímica anti parafibromina en 23 muestras de tejido paratiroideo (5 adenomas, 6 hiper-plasias, 7 normales y 5 carcinomas). Resultados: Se observa un patrón positivo fuerte en casi 100% de la patología benigna y 100% en tejido normal. En los casos de carcinoma sólo 2 de 5 tenían positividad fuerte. Conclusiones: La correlación clínico patológica no permite asociar la pérdida de tinción de parafibromina en algunos casos de cáncer inequívocos. La tinción de parafibromina no permite discriminar entre patología benigna y maligna. Introduction: The definitive diagnosis of parathyroid cancer is extremely difficult, from the clinical approach to the molecular diagnosis. A gene mutation was detected recently in patients with parathyroid cancer. It is a suppressor tumor gene called HRPT2, which codifies for a protein that participates in PAF1 complex, the parafibromin. It has been observed that the expression of this protein it's altered in parathyroid cancer, what would serve like method of diagnosis by immunohystochemistry, with a sensitivity and specificity of 73-96% and 99-100%, respectively. Material and Method: The anti-parafibromin immunohysto-chemistry staining was made in 23 parathyroids tissue samples (5 adenomas, 6 hyperplasia, 7 normal and 5 carcinomas). Results: A positive pattern is observed in almost 100% of benign pathology and 100% in normal tissue. In the cases of carcinoma only 2 of 5 had a strong positivity. Conclusions: The pathological clinical correlation does not allow the association of the loss of parafibromin immunoreactivity in some unequivocal cases of parathyroid cancer. The parafibromin immunostaining does not allow to discriminate between benign or malign pathologies.

14th International Conference on Harmful Algae, 1-5 November 2010, Creta, Greece.-- 3 pages, 1 figure., The objective of the present work was to link Ostreopsis blooms with respiratory problems. To test this hypothesis, samples of seawater, macroalgae, benthic marine invertebrates and aerosols were collected during 2009 and 2010 in the framework of the EBITOX project. Different extraction procedures have been used depending on sample type. The extracts were analysed by haemolytic assay (Riobó et al 2008) and liquid chromatography with fluorescence detection (LC–FLD) (Riobó et al 2006) and the presence of palytoxin was confirmed by liquid chromatography coupled with mass spectrometry (LC-MS) (Riobó et al 2006). Strains isolated from Llavaneres were cultured in the laboratory and analysed by the same chemical and biological methods. Toxins from field samples and cultures were compared. Presence of palytoxins in macroalgae and cultures was confirmed but it has not yet been detected in aerosol filters or dissolved in seawater. Therefore, the hypothesis remains unresolved., This study was funded by the Spanish national project EBITOX (Study of the biological and toxinologic aspects of benthic dinoflagellates associated with risks to the human health) CTQ2008-06754-C04-04. We are in debt with A. Alastuey (Institut Jaume Almera, CSIC) who lent us the aerosol samplers. We acknowledge the support by the Water Catalan Agency (Generalitat de Catalunya), I. Manzano (CZ Veterinaria, S.A. Porriño, Pontevedra) for providing sheep blood for testing hemolytic activity, and facilities offered by the family Aceña from Restaurant Pins Mar (Sant Andreu de Llavaneres).

2 pages, 3 figures.-- The 14th International Conference on Harmful Algae was held in Hersonissos, Crete, 1-5 November 2010, In recent years, Park et al. (2006) succeeded in cultivating the toxic dinoflagellate Dinophysis acuminata using a three-species approach including the ciliate Myrionecta rubra, as Dinophysis prey, grown with a cryptophyte (Teleaulax sp.). After this achievement, several other Dinophysis species have been brought into culture (D. caudata, D. fortii and D.infundibulus; Nagai et al., 2008; Nishitani et al., 2008a; b). In the present study we describe for the first time the morphological variability, genetics and toxin content in cultures of D. tripos, This study was financed by MICINN (DIGEDINO Project, CTM2009-12988-C02-01/MAR). L. Escalera was funded by MIDTAL Project (FP7; Grant no.: 201724)

The controversial molecular identification of the so-called chlorophyll cCS–170 has been settled. Despite its relevance as a potential biomarker in the study of eukaryotic picophytoplankton, the structure of this chlorophyll remained so far uncertain. A full characterization by NMR, UV–vis, and ESI-MS is reported, revealing this chlorophyll as [7-methoxycarbonyl-8-vinyl]-protochlorophyllide a. Versión del editor 6

14th International Conference on Harmful Algae, 1-5 November 2010, Creta, Greece.-- 3 pages, 3 figures, 1 table., Asexual and sexual reproduction were studied in cultures of Ostreopsis cf ovata isolated from several locations in the Mediterranean Sea. Asexual division took place in the motile stage by sharing of the theca (desmoschisis). High cell-size variability was observed in the cultures and differences in division capability were detected. Fusing gamete pairs were the only sexual state confirmed. Most of the gamete pairs isolated divided before the fusion was completed. Pellicle and thecate cysts were the only cyst-like cells which showed germination., We thank Amelia Fernández Villamarin and Isabel Ramilo for providing technical assistance. This work was funded by the Spanish national project EBITOX (CTQ2008- 06754-C04-04). We are also grateful to the CCVIEO-Microalgae Culture Collection of Instituto Español de Oceanografía.

Harmful Algal Blooms (HAB) of toxin producing microalgae that, even at low cell densities, cause accumulation of unsafe levels of toxins in filter-feeders, pose a major natural hazard for public health and the sustainable exploitation of shellfish resources. Key questions are why blooms of the same species have chronic devastating effects in some parts of the world and hardly cause any damage elsewhere, and what are the suite of environmental conditions triggering the expression of toxin synthesis and its seasonal and interannual variability. Answers to these questions require understanding of the complex processes involved in toxin production by microalgae and their availability to filter and deposit feeders, and the species-specific behaviour of molluscan shellfish organisms. This chapter revises current knowledge on intrinsic (genetically determined) and environmental factors affecting toxin production by microalgae, their accumulation in dense populations (controlled by hydroclimatic processes) and the species-specific responses of filter feeders to the uptake, biotransformation and elimination of each group of toxins. New avenues opened by advanced molecular biology applications to address these questions are discussed. Versión editor

4 pages, 1 table, 1 figure.-- The 15th International Conference on Harmful Algae was held in Changwon, Korea, 29 October – 2 November 2012, We studied the feeding behaviour of several Fragilidium strains of F. duplocampanaeforme and F. subglobosum from the Atlantic, NW Iberian coast, towards four Dinophysis species (D. acuminata, D. acuta, D. caudata and D. tripos). LC-MS analyses were performed to follow the fate of toxins in the water or their transference from Dinophysis cells to Fragilidium. Different feeding behaviour and mechanisms were observed among the Fragilidium strains: F. duplocampanaeforme fed upon D. acuminata and D. caudata but not on D. acuta and weakly on D. tripos. Fragilidium engulfed these preys directly through the sulcus as previously described. Allelopathic effects toward certain but not all Dinophysis species studied were observed. Frequency of gamete-like small forms of F. duplocampanaeforme was much higher (>50%) in cultures preying on Dinophysis (D. acuminata and D. caudata) than in those (, Funded by projects DINOPOL, Plan Nacional I+D+I (CTM2009-12988-C02-01) and “Aislamiento y purificación de espirólidos a partir de cultivos de Alexandrium ostenfeldii” CSIC -PIE- 201270E032

A new benthic toxic dinoflagellate is described from the Canary Islands, Spain. Gambierdiscus excentricus sp. nov. was isolated from seaweeds growing in tidal ponds and was observed in winter and summer. Its morphology was studied by means of light microscopy (LM) and scanning electron microscopy (SEM); G. excentricus is a lenticular species having a Po plate ventrally displaced in relation to other species of the genus Gambierdiscus. Phylogenetic trees from large subunit (LSU) of ribosomal RNA gene sequences displayed a topology confirming that G. excentricus clustered in its’ own group, separated from the rest of Gambierdiscus species and with Gambierdiscus australes as its closest relative. Pigment composition studied from G. excentricus cultures, included peridinin, as the major carotenoid, chlorophyll a and the accessory chlorophylls c1 and c2. The Neuroblastoma cell-based assays for ciguatoxins (CTX) and maitotoxin (MTX) confirmed G. excentricus as a CTX- and MTX-like compounds producer. The finding of a toxic species of Gambierdiscus in the Canary Islands may explain the recent reported cases of ciguatera in the area., Sí

The pigment composition of 18 species (51 strains) of the pennate diatom Pseudo-nitzschia was examined using HPLC. The carotenoid composition was typical for diatoms, with fucoxanthin (the major xanthophyll), diadinoxanthin, diatoxanthin, and β,β-carotene. However, a diverse array of chl c pigments was observed in the studied strains. All Pseudo-nitzschia strains contained chl a and chl c2, traces of Mg-2,4-divinyl phaeoporphyrin a5 monomethyl ester (MgDVP), and traces of a chl c2–like pigment originally found in the haptophyte Pavlova gyrans. The distribution of chl c1 and chl c3 was variable among species (present in seven and 14 species, respectively). Based on chl c distribution, three major pigment types were defined: type 1 (chl c1 + c2, four species: P. australis, P. brasiliana, P. multiseries, and P. seriata), type 2 (chl c1 + c2 + c3, three species: P. fraudulenta, P. multistriata, and P. pungens), and type 3 (chl c2 + c3, 11 species: P. arenysensis, P. calliantha, P. cuspidata, P. decipiens, P. delicatissima, P. galaxiae, P. mannii, P. pseudodelicatissima, P. subcurvata, P. cf. subpacifica, and a novel Pseudo-nitzschia species). Type 1 and 2 species also shared the absence of a particular morphological character, the central nodule in the raphe, with the only exception of P. fraudulenta. The implications of such pigment diversity in chemotaxonomy, HAB monitoring, ecology, and phylogeny of Pseudo-nitzschia species are discussed., Sí

14th International Conference on Harmful Algae, 1-5 November 2010, Creta, Greece.-- 3 páginas., Epiphytic dinoflagellates of the genus Ostreopsis have been related to harmful episodes in many Mediterranean coastal areas since 1998: respiratory difficulties, fever, and skin irritations affected people exposed to marine aerosols by recreational activities on the beach. Although this genus is widespread in most of the Mediterranean coasts, harmful events have been recorded only in some localities and periods. One of those sites has been studied for 3 years in a high frequency monitoring (EBITOX project) in order to elucidate the relationship between the microalgal community and its toxicity., This study was funded by the Spanish national project EBITOX (Study of the biological and toxinologic aspects of benthic dinoflagellates associated with risks to the human health) CTQ2008-06754-C04-04. We are in debt with A. Alastuey (Institut Jaume Almera, CSIC) who let us the aerosol samplers. We also acknowledge the support given by the Water Catalan Agency (Generalitat de Catalunya), I. Manzano (CZ Veterinari, S.A. Porriño, Pontevedra) for providing sheep blood for testing the hemolytic activity, and the facilities kindly offered by the family Aceña from the Restaurant Pins Mar (Sant Andreu de Llavaneres).

Background: Postoperative hypocalcemia is one of the most common complications of thyroid surgery. It is related to the type of disease (malignant or benign), the number of identified parathyroid glands during the surgical procedure, and the surgeon's experience. Total thyroidectomy is the procedure of choice in our hospital for benign and malignant thyroid disease, but it can increase the incidence of complications. Aim: To evaluate the incidence of postoperative hypocalcemia in patients subjected to a total thyroidectomy. Material and methods: Two studies were performed. A retrospective review of medical records of 448 patients subjected to total thyroidectomy, looking for serum calcium levels of less than 8 mg/dl and clinical signs of hypocalcemia. In a second study, 45 patients were followed with measurements of preoperative and postoperative serum calcium levels. Results: In the retrospective study, only 136 records had reliable information. Clinical signs of hypocalcemia were registered in 14% of patients and a low serum calcium level was detected in 50%. In the prospective study, 42% of patients had a postoperative low serum calcium level and seven patients (15%) had symptoms. Patients were handled with oral calcium and calcitriol in some cases. Ninety nine percent of patients had normal serum calcium levels two moths after surgery. Conclusions: In this series, the rate of postoperative hypocalcemia after total thyroidectomy is similar to internaitonal reports