Characterization of a Strain of Fukuyoa paulensis (Dinophyceae) from the Western Mediterranean Sea

17 páginas, 8 figuras, 4 tablasA single cell of the dinoflagellate genus Fukuyoa was isolated from the island of Formentera (Balearic Islands, west Mediterranean Sea), cultured, and characterized by morphological and molecular methods and toxin analyses. This is the first report of the Gambierdiscus lineage (genera Fukuyoa and Gambierdiscus) from the western Mediterranean Sea, which is cooler than its eastern basin. Molecular analyses revealed that the Mediterranean strain belongs to F. paulensis and that it bears LSU rDNA sequences identical to New Zealand, Australian, and Brazilian strains. It also shared an identical sequence of the more variable ITS-rDNA with the Brazilian strain. Toxin analyses showed the presence of maitotoxin, 54-deoxyCTX1B, and gambieric acid A. This is the first observation of the two latter compounds in a Fukuyoa strain. Therefore, both Gambierdiscus and Fukuyoa should be considered when as contributing to ciguatera fish poisoning. Different strains of Fukuyoa form a complex of morphologically cryptic lineages where F. paulensis stands as the most distantly related nominal species. The comparison of the ITS2 secondary structures revealed the absence of CBCs among strains. The study of the morphological and molecular traits depicted an unresolved taxonomic scenario impacted by the low strains samplingFinancial support for this research was provided by the Basque Government (project IT699-13). A grant from the University of the Basque Country (UPV/EHU) to H. David also supported this studyPeer reviewe

Inventario y distribución de la herpetofauna en Jaizkibel

Se ha actualizado el conocimiento de la comunidad herpetológica del macizo de Jaizkibel, después de largo tiempo de ausencia de publicaciones, mediante un inventario basado en trabajo de campo comprendido entre los meses de Abr. a Oct. de 2012, al que se han añadido observaciones acumuladas durante el último decenio. La comunidad está compuesta por 4 especies de anfibios y 11 especies dereptiles, en general distribuidas por la mayor parte del enclave y cuyo origen filogenético mayoritario es el continente europeo. No se ha podido confirmar la presencia del lagarto verdinegro Lacerta schreiberiBedriaga, 1878, citado una sola vez en 198

Rapid colour changes in Euglena sanguinea (Euglenophyceae) caused by internal lipid globule migration

The accumulation of red pigments under chronic stress is a response observed in most groups of oxygenic photoautotrophs. It is thought that the red pigments in the cell shield the chlorophyll located underneath from the light. Among these red pigments, the accumulation of carotenoids is one of the most frequent cases. However, the synthesis or degradation of carotenoids is a slow process and this response is usually only observed when the stress is maintained over a period of time. In the Euglenophyte Euglena sanguinea, this is due to the accumulation of a large amount of free and esterified astaxanthin (representing 80% of the carotenoid pool). While reddening is a slow and sometimes irreversible process in other phototrophs, reducing the efficiency of light harvesting by chlorophyll, in E. sanguinea it is highly dynamic, capable of shifting from red to green (and vice-versa) in 10-20 min. This change is not due to de novo carotenogenesis, but to the relocation of cytoplasmic lipid globules where astaxanthin accumulates. Thus, red globules migrate from the centre of the cell to peripheral locations when photoprotection is demanded. This protective system seems to be so efficient that other classical mechanisms are not operative in this species. For example, despite the presence and operation of the diadino-diatoxanthin cycle, nonphotochemical quenching (NPQ) is almost undetectable. Since E. sanguinea forms extensive floating colonies, reddening can be observed at much greater scale than at a cellular level, the mechanism described here being one of the fastest and most dramatic colour changes attributable to photosynthetic organisms at cell and landscape level. In sum, these data indicate an extremely dynamic and efficient photoprotective mechanism based on organelle migration more than on carotenoid biosynthesis that prevents excess light absorption by chlorophylls reducing the need for other protective processes related to energy dissipation.This work was supported by the Basque Government [UPV/EHU-GV IT-1018-16] [UPV/EHU PPG17/67 – GV IT-1040-16], and by the Spanish Ministry of Economy and Competitiveness (MINECO) and the European Research and Development Foundation (FEDER) through (i) [CTM2014-53902-C2-2-P] national grant and (ii) a “Juan de la Cierva-Incorporación” postdoctoral grant [IJCI-2014-22489] to BFM

Inhomogeneity detection in phytoplankton time series using multivariate analyses

Phytoplankton communities have long been used as water quality indicators within environmental policies. This has fostered the development of national and international phytoplankton monitoring programs, but these networks are subject to sources of uncertainty due to laboratory issues. Nevertheless, studies regarding the interference associated with these aspects are not well-documented. Hence, a long time series (2003-2015) from the Basque continental shelf (southeastern Bay of Biscay) was analyzed to evaluate the uncertainty given by laboratory strategies when studying phytoplankton variability. Variability in phytoplankton communities was explained not only by environmental conditions but also by changes in fixatives (glutaraldehyde and acidic Lugol's solution) and laboratory staff. Based on Bray-Curtis distances, phytoplankton assemblages were found to be significantly dissimilar according to the effect of changes in the specialist handling the sample and the employed fixative. The pair-wise permutational multivariate analysis of variance (PERMANOVA) showed significant differences between the two fixatives utilized and also between the three taxonomists involved. Thus, laboratory-related effects should be considered in the study of phytoplankton time series.The data for this study were obtained from the project "Program for the monitoring and assessment of the ecological status of transitional and coastal waters of the Basque Country" funded by URA, the Basque Water Agency, through a convention with AZTI. This work was supported by the project "IM17MUSSELS". The participation of O. Muniz was funded by a grant from the Department of Economic Development and Competitiveness of the Basque Government (BOPV num. 201; 2013/4467). This paper is contribution number 956 from AZTI (Marine Research Division). We also thank Proof-Reading-Service for their great professional proof reading and editing service, as well as the anonymous reviewers for their comments and suggestions

Operational oceanography applied to the management of offshore aquaculture on the Basque coast (SE Bay of Biscay)

With the support of the Basque Government, offshore longlines have been used for mussel production in Mendexa (“Bivalve Mollusc Production Area”) since 2019. This area is located about 2 nautical miles from the Basque coast (SE Bay of Biscay). Here, an Integrated Marine Observing System (IMOS) has been established to identify toxic HABs. This system includes in situ data, sampling activity, satellite images, numerical models and other external sources of information.Peer Reviewe

Assessment of a Sheltered Euhaline Area of the Southeastern Bay of Biscay to Sustain Bivalve Production in Terms of Phytoplankton Community Composition

This study describes the phytoplankton community in sheltered euhaline waters of the Basque coast (southeastern Bay of Biscay). Phytoplankton composition, cell size, abundance, biomass and the presence of potentially toxic taxa, together with chlorophyll a, nutrients and hydrographic and optical conditions were measured, from August 2016 to August 2017, in the Mutriku port, with the main aim of assessing the suitability of the phytoplankton community as a food resource for bivalves. The water column in Mutriku showed the typical environmental conditions of Basque marine waters, with no significant nutrient enrichment caused by anthropogenic pressures. Haptophytes represented the greatest contribution to cell abundance (31-47%), and diatoms were the dominant group in terms of biomass (52-79%),which could favour mussel growth due to their high fatty acid content. In addition, the size structure of the phytoplankton community was suitable for mussel ingestion, since the predominant cell size was 2-20 mu m. Regarding toxic phytoplankton, the genera that pose a risk for human health and those that affect negatively mussel physiology and survival were considered. Altogether, ten toxic phytoplankton taxa were identified, contributing in less than 5% to the total cell abundance of Mutriku. However, median chlorophyll a concentration was low (0.5 mu g L-1), reflecting the oligotrophic conditions of the area. Therefore, even if the composition of the phytoplankton community could be favourable for bivalve aquaculture, biomass values are low compared to other zones of bivalve productionThis study was partially supported by the project EGRECOST CALIDAD -Control de Calidad de Aguas Cultivos Marinos (Departamento de Desarrollo Economico e Infraestructuras del Gobierno Vasco) and the project PPG17/67 funded by the University of the Basque Country (UPV/EHU). J. Bilbao was funded by a grant from the University of the Basque Country (UPV/EHU -PIF 18/306). This paper is contribution number 991 from AZTI (Marine Research Division

Scaly green flagellates from Spanish Atlantic coastal waters: molecular, ultrastructural and pigment analyses

24 páginas, 3 tablas, 86 figurasSeven scale-bearing species of prasinophyceans (Chlorophyta) were studied in light and electron microscopy, pigment analysis, and molecular analysis of the small subunit (SSU) rDNA. Unialgal cultures were obtained from samples collected in the Nervión River estuary, Gulf of Biscay, Spanish Atlantic coast. Five of the species belong to the genus Pyramimonas (Prasinophyceae, Pyramimonaceae) and one each to the genera Mamiella (Mamiellophyceae, Mamiellaceae) and Nephroselmis (Nephroselmidophyceae, Nephroselmidaceae). The morphological features of all the strains analyzed agreed closely with the phylogenetic analysis, which in the case of the genus Pyramimonas presented several clusters corresponding to the subgenera Vestigifera (Pyramimonas orientalis, Pyramimonas moestrupii), Punctatae (Pyramimonas robusta), Pyramimonas (Pyramimonas propulsa), and Trichocystis (Pyramimonas grossii). Even though the phylogenetic relationship among these subgenera remains unclear, the results suggested that the Punctatae should remain an independent clade at least until more sequences or genes are analyzed. According to their accessory pigment composition, three groups were distinguished after their pigment ratios were calculated: prasinoxanthin-containing (Mamiella gilva), loroxanthin ester-containing (P. grossii and P. moestrupii), and siphonaxanthin- containing strains (Nephroselmis pyriformis and remaining Pyramimonas species). A high intraspecific variability was found, which highlights the need of an indepth analysis and multiple technique approach to ensure accurate identification of nanoplanktonic microalgaeSpanish Ministry of Economy and Competitiveness, (Grant/Award Number: ‘projects CGL2010-19016 and GIC07/111-417-07’), Spanish Ministry of Education and Science, (Grant/Award Number: ‘CMT2006-04570/MAR’), University of the Basque Country (UPV/EHU)Peer reviewe