%0 Journal Article %J European Journal of Taxonomy %D 2023 %T New species of Pavlovophyceae (Haptophyta) and revision of the genera Exanthemachrysis, Rebecca and Pavlova %A Benoît Véron %A Rougier, Etienne %A Taylor, Anthony %A Goux, Didier %K habitats %K Haptophytes %K New species %K Phytoplankton %K pyrenoid. %X The justification of the 4 genera that currently compose the class Pavlovophyceae is based on a low number of species and a relative paucity of available, traceable and referenced cultures. Previous integrative phylogeny work revealed strains that can refine and strengthen our knowledge of the genera in the class. The application of multiple light and electron microscopy techniques allowed us to prioritize the cytomorphological characters (pyrenoid, thylakoid, stigma, knob-scales, life stage / life cycle) used for the taxonomy of these algae and to describe two new species: Exanthemachrysis fresneliae Véron sp. nov. and Rebecca billardiae Véron sp. nov. Consequently, revisions of the two genera Exanthemachrysis Lepailleur emend. Véron and Rebecca Green emend. Véron were made. In addition, the genus Pavlova Butcher emend Véron is revised in the light of these characters. Particular emphasis is placed on the life stages and habitat of the species. %B European Journal of Taxonomy %V 861 %P 21 - 47 %8 08-03-2023 %G eng %U https://europeanjournaloftaxonomy.eu/index.php/ejt/article/view/2063 %! Two new species of Pavlovophyceae (Haptophyta) %R 10.5852/ejt.2023.861.2063 %0 Journal Article %J Harmful Algae %D 2020 %T Seasonal variations of phytoplankton assemblages in relation to environmental factors in Mediterranean coastal waters of Morocco, a focus on HABs species %A Benlahcen Rijal Leblad %A Rachid Amnhir %A Sagou Reqia %A Ferdaous Sitel %A Mohamed Marhraoui %A Mohamed Karim Ouelad Abdellah %A Benoît Véron %A Hassan Er-Raioui %A Mohamed Laabir %X Studies on phytoplankton and in particular Harmful Algal Blooms (HABs) species in southern Mediterranean waters are scarce. We performed from April 2008 to June 2009 weekly investigations on microphytoplankton community structure and abundance in two contrasted marine ecosystems located in the western Moroccan Mediterranean coast, M'diq Bay and Oued Laou Estuary. Simultaneously, we measured the main physico-che- mical parameters. Globally, the two studied areas showed comparable values of the assessed abiotic environ- mental factors. Temperature and salinity followed seasonal variation with values ranging from 13.5 °C to 21.4 °C and 31 to 36.8, respectively. Average nutrient values in surface water ranged from 0.7 to 45.76 μM for dissolved inorganic nitrogen, 0.02–2.10 μM for PO4 and 0.23–17.46 μM for SiO4 in the study areas. A total of 92 taxa belonging to 8 taxonomic classes were found. The highest number of microphytoplankton abundance reached 1.2 × 106 cells L−1 with diatoms being the most abundant taxa. Factorial Discriminant Analysis (FDA) and Spearman correlation test showed a significant seasonal discrimination of dominant microphytoplankton spe- cies. These micro-organisms were associated with different environmental variables, in particular temperature and salinity. Numerous HABs species were encountered regularly along the year. Although Dinophysis species and Prorocentrum lima were present in both sites, no Lipophilic Shellfish Poisoning was detected for the analyzed bivalve mollusks. Domoic acid (DA), produced by toxic species of Pseudo-nitzschia was found with concentrations up to 18 μg DA g−1 in the smooth clam Callista chione. Data showed that the observed persistent and dramatic Paralytic Shellfish Poisoning (PSP) intoxication of mollusks resulted probably of Gymnodinium catenatum pro- liferations in both studied areas. Contrary to C. chione, the cockle Achanthocardia tuberculatum showed a per- manent and extremely high toxicity level during the 15 months survey with up to 7545 μg Equivalent Saxitoxin kg−1 flesh (ten times higher than the sanitary threshold of 800 μg eqSTX Kg−1flesh). The present work high- lights for the first time the dynamic of microphytoplankton including HABs species and their associated toxin accumulation in the commercially exploited shellfish in the southern western Mediterranean waters of Morocco. Furthermore, the acquired data will help us to improve the monitoring of HABs species and related toxins in these coastal marine systems. %B Harmful Algae %V 96 %P 101819 %G eng %0 Journal Article %J Harmful Algae %D 2020 %T Seasonal variations of phytoplankton assemblages in relation to environmental factors in Mediterranean coastal waters of Morocco, a focus on HABs species %A Rijal Leblad, Benlahcen %A Amnhir, Rachid %A Reqia, Sagou %A Sitel, Ferdaous %A Daoudi, Mouna %A Marhraoui, Mohamed %A Ouelad Abdellah, Mohamed Karim %A Benoît Véron %A Er-Raioui, Hassan %A Laabir, Mohamed %B Harmful Algae %V 96 %P 101819 %8 Jan-06-2020 %G eng %U https://linkinghub.elsevier.com/retrieve/pii/S1568988320300986 %! Harmful Algae %R 10.1016/j.hal.2020.101819 %0 Journal Article %J Journal of Materials and Environmental Sciences %D 2017 %T Contamination and depuration of Paralytic Shellfish Poisoning by Acanthocardia tuberculata cockles and Callista chione clams in Moroccan waters %A B. Rijal Leblad %A H. Nhhala %A M. Daoudi %A M. Marhraoui %A M. K. Ouelad Abdellah %A Benoît Véron %A H. Er-Raioui %X This study of Gymnodinium catenatum was conducted across two sampling stations; M'diq bay and Oued Laou estuary during the period from July 2007 to May 2009. Gymnodinium catenatum blooms occurred after a rainfall event in autumn and early winter. Statically analyses showed a positive correlation with rainfall. During January 2008, the G. catenatum bloom resulted in contamination of tuberculate cockles and sweet clam by Paralytic Shellfish Poisoning (PSP) toxins. In the Oued Laou estuary, the levels of these toxins in shellfish went beyond the normative threshold for consumption of shellfish, (80 μg SXTeq. /100g of meat) and reached (710 ± 82.07) and (198 ± 6.56) μg SXTeq. /100g of meat in cockles and sweet clam respectively. In M'diq bay, concentrations of PSP toxins in the meat of these two shellfish were lower (256.57 ± 12.22 μg SXTeq. /100g and 80.66 ± 8.14 μg SXTeq. /100g of meat in tuberculate cockles and sweet clam respectively. An experimental test of depuration of tuberculate cockles and sweet clam contaminated by the PSP toxins was conducted in laboratory conditions in the first week of January 2008. The results showed partial and progressive elimination of PSP toxins in two shellfish species over time. In the tuberculate cockle, the elimination of PSP appears to be slower compared with the sweet clam; it took 120 days to reach levels of 80 μg SXTeq. /100g of meat, on the other hand only 3 days were needed to reach this safe concentration in the sweet clam. %B Journal of Materials and Environmental Sciences %V 8 %P 4634-4641 %G eng %N S %0 Journal Article %J Hydrobiologia %D 2014 %T Complex patterns in phytoplankton and microeukaryote diversity along the estuarine continuum %A Bazin, Pauline %A Fabien Jouenne %A Deton-Cabanillas, Anne-Flore %A Perez-Ruzafa, Angel %A Benoît Véron %K 18S rDNA clone libraries %K Diversity %K Estuarine gradient %K Microeukaryotes %K Microscopy %K Phytoplankton %K semiarid area %B Hydrobiologia %V 726 %P 155-178 %G eng %R 10.1007/s10750-013- 1761-9 %0 Journal Article %J PLoS One %D 2014 %T Phytoplankton diversity and community composition along the estuarine gradient of a temperate macrotidal ecosystem: combined morphological and molecular approaches. %A Bazin, Pauline %A Fabien Jouenne %A Friedl, Thomas %A Deton-Cabanillas, Anne-Flore %A Bertrand Le Roy %A Benoît Véron %X

Microscopical and molecular analyses were used to investigate the diversity and spatial community structure of spring phytoplankton all along the estuarine gradient in a macrotidal ecosystem, the Baie des Veys (eastern English Channel). Taxa distribution at high tide in the water column appeared to be mainly driven by the tidal force which superimposed on the natural salinity gradient, resulting in a two-layer flow within the channel. Lowest taxa richness and abundance were found in the bay where Teleaulax-like cryptophytes dominated. A shift in species composition occurred towards the mouth of the river, with the diatom Asterionellopsis glacialis dramatically accumulating in the bottom waters of the upstream brackish reach. Small thalassiosiroid diatoms dominated the upper layer river community, where taxa richness was higher. Through the construction of partial 18S rDNA clone libraries, the microeukaryotic diversity was further explored for three samples selected along the surface salinity gradient (freshwater - brackish - marine). Clone libraries revealed a high diversity among heterotrophic and/or small-sized protists which were undetected by microscopy. Among them, a rich variety of Chrysophyceae and other lineages (e.g. novel marine stramenopiles) are reported here for the first time in this transition area. However, conventional microscopy remains more efficient in revealing the high diversity of phototrophic taxa, low in abundances but morphologically distinct, that is overlooked by the molecular approach. The differences between microscopical and molecular analyses and their limitations are discussed here, pointing out the complementarities of both approaches, for a thorough phytoplankton community description.

%B PLoS One %V 9 %P e94110 %8 2014 %G eng %N 4 %1 http://www.ncbi.nlm.nih.gov/pubmed/24718653?dopt=Abstract %R 10.1371/journal.pone.0094110