Resumen Introducción: Las lagunas salobres son ecosistemas de alta diversidad y con posibilidades para uso humano. Por lo que es necesario mejorar el conocimiento del fitoplancton para entender su impacto real. Objetivo: Relacionar el fitoplancton de la Laguna Mandinga con las condiciones limnológicas durante épocas de secas y lluvias. Métodos: El material se recolectó en tres estaciones: Isla Conchas (ICO), Mandinga Chica (MCH) e Isla del Amor (IA) en secas (marzo 2018) y lluvias (septiembre 2017 y 2018). El análisis limnológico incluyó diez variables abióticas, además del fitoplancton mediante el método de Utermöhl. Los datos fueron analizados por el índice de Shannon (H') y Correspondencia Canónica (ACC). Resultados: Análisis de 136 especies; 68.4 % Heterokontophyta, 22.8 % Dinoflagellata, 5.9 % Cyanobacteria; con 40 eurihalinas y 96 estenohalinas. Las especies más abundantes fueron: Bacillaria paxillifera, Chaetoceros compressus, Coscinodiscus rothii y Chaetoceros atlanticus. La mayor abundancia se registró en ICO (secas) y la menor en MCH (lluvias) con 307 x 103 y 76 x 103 cell/ml, respectivamente. El H' osciló entre 1.31 y 0.70 bits/ind. El CCA mostró una relación entre salinidad y oxígeno disuelto con C. rothii y Ceratoneis closterium. Los fosfatos se asociaron con B. paxillifera, C. atlanticus y Podosira stelligera. Los nitratos, temperatura y pH se correlacionaron con Tripos hircus, T. furca, Diploneis bombus y Merismopedia elegans. Mientras, Skeletonema costatum, Cocconeis scutelum y Nitzschia bicapitata no presentaron correlación con las variables limnológicas. Conclusiones: La Laguna Mandinga es un ecosistema somero, eurihalino y bien oxigenado. La dominancia de diatomeas y dinoflagelados se evidenció por su capacidad para sobrevivir en diferentes concentraciones de salinidad y temperatura. Sugerimos monitorear al fitoplancton por la presencia de Microcystis wesenbergii, B. quinquecornis, Pseudo-nitzschia cf. pungens y P. cf. pseudodelicatissima ya que pueden formar proliferaciones dañinas.

Abstract Introduction: The brackish lagoons are ecosystems with great diversity and possibilities for human use. Therefore, the knowledge about phytoplankton needs to be improved to understand its real impact. Objective: To relate the Mandinga’s Lagoon phytoplankton to the limnological conditions during the dry and wet seasons. Methods: The material was collected in three stations: Isla Conchas (ICO), Mandinga Chica (MCH) and Isla del Amor (IA) during the dry (March 2018) and wet (September 2017 and 2018) seasons. The limnological analysis included ten abiotic variables, and the phytoplankton was analyzed by the Utermöhl method. Data was analyzed with the Shannon index (H') and Canonical Correspondence Analysis (CCA). Results: 136 species were identified: 68.4 % Heterokontophyta, 22.8 % Dinoflagellata, and 5.9 % Cyanobacteria; with 40 euryhaline and 96 stenohaline. The most abundant species were: Bacillaria paxillifera, Chaetoceros compressus, Coscinodiscus rothii, and Chaetoceros atlanticus. The highest abundance was in ICO (dry) and the lowest in MCH (wet), with 307 x 103 and 76 x 103 cells/ml, respectively; the H' ranged from 1.31 to 0.70 bits/ind. The CCA showed a relationship between salinity and dissolved oxygen with C. rothii and Ceratoneis closterium. The phosphates were associated with B. paxillifera, C. atlanticus, and Podosira stelligera. The nitrate, water temperature and pH were related to Tripos hircus, T. furca, Diploneis bombus, and Merismopedia elegans. In contrast, Skeletonema costatum, Cocconeis scutelum, and Nitzschia bicapitata did not correlate with the limnological variables. Conclusions: The Mandinga’s Lagoon is a shallow, euryhaline and well-oxygenated ecosystem. The dominance of diatoms and dinoflagellates was evidenced by their ability to survive in different salinities and temperatures. It is recommended monitor phytoplankton, in particular Microcystis wesenbergii, B. quinquecornis, Pseudo-nitzschia cf. pungens, and P. cf. pseudodelicatissima as they are harmful algae.

Resumen Introducción: Las bahías bioluminiscentes en Puerto Rico desempeñan un papel socioeconómico importante y disminuciones del dinoflagelado bioluminiscente dominante Pyrodinium bahamense son preocupantes. Los estudios muestran proliferaciones erráticas débilmente correlacionadas con factores ambientales locales. Objetivos: Cuantificar cambios en la densidad de dinoflagelados a largo plazo en la Laguna Grande de Fajardo (LGF), comprender cómo el ambiente marino modula esos cambios y determinar los impactos de eventos climáticos extremos en la densidad de dinoflagelados. Métodos: Se recolectaron muestras bimestrales del 2016-2021 en tres sitios de la LGF. La densidad se estimó mediante el conteo de células de Sedgewick Rafter. Condiciones ambientales se obtuvieron de la estación Río Fajardo 5007100 y de la boya NOAA 41056. El clima marino y los indicadores bióticos se obtuvieron por mediciones de teledetección. Se utilizaron correlaciones Kruskal Wallis, Spearman y las correlaciones cruzadas en los registros de campo corto y proxy largos para evaluar los controles ambientales en las proliferaciones de dinoflagelados LGF. Resultados: En seis años de monitoreo se encontraron densidades bajas entre el 2016-2017 y proliferaciones frecuentes e intensas en 2018-2021 marcadas por huracanes. Se registraron valores bajos a finales del invierno, en contraste con valores más altos a finales del verano (agosto-noviembre). Vientos ligeros y la respuesta de capas mixtas al calentamiento estacional en forma de mareas altas y baja salinidad, mantienen la reproducción de los dinoflagelados. Conclusiones: Los dinoflagelados bioluminiscentes son vitales para el turismo costero y requieren manejo de los recursos. En general: 1) los recuentos de dinoflagelados fluctúan ampliamente, 2) los dinoflagelados fluorescentes son sensibles a las condiciones ambientales debido a su estacionalidad limitada y estrecho rango fisiológico, 3) los huracanes juegan un rol de rastrillar y refrescar la laguna costera para su posterior reproducción, y 4) fluctuaciones intra-estacionales se relacionan con las condiciones termodinámicas aire-mar, el balance de salinidad y el nivel del mar.

Abstract Introduction: Bio bays in Puerto Rico play an important socio-economic role and declines in dominant bioluminescent dinoflagellate Pyrodinium bahamense are concerning. Studies show erratic blooms with is weak correlation to in situ environmental factors. Our study examines shorter field and longer proxy records on dinoflagellate density at Laguna Grande de Fajardo (LGF). Objectives: To quantify temporal changes in dinoflagellate density in a long-term monitoring study, understand how the marine environment modulates those changes, and determine the wider impacts of a fluctuating climate and extreme events on proxies for dinoflagellate density. Methods: Bimonthly samples were collected from 2016 to 2021 at three sampling sites in LGF. Dinoflagellates density was estimated by Sedgewick Rafter counting cells. Environmental conditions were obtained from Rio Fajardo 5007100 station and NOAA buoy 41056. Marine climate and biotic proxies were obtained from remote sensing measurements. Kruskal Wallis, Spearman correlations and cross-correlations in the shorter field and longer proxy records were used to evaluate environmental controls on LGF dinoflagellate blooms. Results: Six years of field monitoring densities found a low period in 2016-2017, frequent and intense blooms in 2018-2021 punctuated by hurricanes. Generally low values were recorded in late winter in contrast with higher values in late summer (Aug-Nov). Light winds and mixed layer response to seasonal warming in the form of high tides and low salinity, were found to sustain dinoflagellate reproduction. Conclusions: Bioluminescent dinoflagellates are vital to coastal tourism and require resource management. LGF results show that: 1) dinoflagellate counts fluctuate widely, 2) fluorescing dinoflagellates are sensitive to environmental conditions because of limited seasonality and narrow physiological range, 3) hurricanes play a role by ‘raking and refreshing’ the coastal lagoon for subsequent biotic reproduction, and 4) intra-seasonal fluctuations of density and proxies relate to air-sea thermodynamic conditions, the salinity budget and sea level.

Resumen La Reserva de la Biosfera Isla Guadalupe (RBIG) se localiza a 241 km de la costa occidental de México, siendo uno de los territorios insulares más distante del país. Por lo tanto, el estudio de su biodiversidad en el contexto biogeográfico resulta de gran interés. El objetivo del presente estudio fue presentar los primeros registros de dinoflagelados de la RBIG. Se enlistan e ilustran 34 especies y taxones infraespecíficos de dinoflagelados. Todas las especies ya han sido registradas para las aguas costeras mexicanas y dos de ellas, Dinophysis tripos y Phalacroma mitra, se han reportado en la literatura, como productoras de toxinas. Este estudio representa el primer aporte al conocimiento de los dinoflagelados de la RBIG.

Abstract The Guadalupe Island Biosphere Reserve (RBIG) is located 241 km from Mexico's western coast and is thus one of the most distant island territories in the country. Therefore, studying its biodiversity is of great interest in a biogeographic context. This study aimed to present the first records of dinoflagellates found in the RNIG. Thirty-four dinoflagellate species and infraspecific taxa were reported and illustrated. All species have been previously recorded in Mexican coastal waters, and two of them, Dinophysis tripos and Phalacroma mitra, have been reported in the literature as toxin producers. This study represents the first contribution to the knowledge of dinoflagellates in the RBIG.

Resumen Se monitorearon las aguas costeras de 6 playas recreativas en la costa de Campeche en el golfo de México de marzo a octubre de 2019. Los rangos de temperatura, salinidad y pH variaron según la temporada y probablemente estuvieron influenciados por la hidrografía local y la poca profundidad del área de estudio. Los taxones nocivos identificados en este estudio incluyeron 3 especies de diatomeas, 5 dinoflagelados y 2 cianobacterias, con abundancias que oscilaron entre 102 y 105 cél·L-1. Dentro de la comunidad de fitoplancton, los fitoflagelados (nanofitoplancton <20 µm) exhibieron una abundancia máxima de 1.6 × 106 cél·L-1 en Boca del Río en Champotón. El microfitoplancton (>20 µm), incluidas diatomeas, dinoflagelados y cianobacterias, fue un componente secundario con densidades que oscilaron entre 103 y 106 cél·L-1. El dinoflagelado Pyrodinium bahamense, identificado como tóxico para los humanos en la costa de Campeche, mostró una abundancia máxima de 2.0 × 105 cel·L-1 en mayo en Boca del Río. La diatomea tóxica Pseudo-nitzschia exhibió una abundancia máxima de 105 cél·L-1 en Payucan en mayo. Los géneros de cianobacterias Anabaena y Trichodesmium exhibieron abundancias que oscilaron entre 102 y 104 cél·L-1. En todas las estaciones y meses se presentaron fitoplancton y cianobacterias potencialmente dañinos, lo que indica que es necesario un monitoreo continuo para evaluar la calidad de las playas y garantizar la seguridad de las playas recreativas.

Abstract The coastal waters of 6 recreational beaches on the coast of Campeche in the Gulf of Mexico were monitored from March to October 2019. Temperature, salinity, and pH ranges varied depending on the season and were likely influenced by the local hydrography and shallow depth of the study area. The harmful taxa identified in this study included 3 diatom, 5 dinoflagellate, and 2 cyanobacteria species, with abundances ranging from 102 to 105 cell·L-1. Within the phytoplankton community, phytoflagellates (nanophytoplankton <20 µm) exhibited a peak abundance of 1.6 × 106 cell·L-1 at Boca del Río in Champotón. Microphytoplankton (>20 µm), including diatoms, dinoflagellates, and cyanobacteria, were a secondary component with densities ranging from 103 to 106 cell·L-1. The dinoflagellate Pyrodinium bahamense, identified as toxic to humans on the Campeche coast, showed a maximum abundance of 2.0 × 105 cell·L-1 in May at Boca del Río. The toxic diatom Pseudo-nitzschia exhibited a peak abundance of 105 cell·L-1 at Payucan in May. The cyanobacteria genera Anabaena and Trichodesmium exhibited abundances ranging from 102 to 104 cell·L-1. Potentially harmful phytoplankton and cyanobacteria were present in all seasons and months, indicating that continual monitoring is needed to assess beach quality to ensure the safety of recreational beaches.

Resumen Se registra por primera vez el género de dinoflagelado Metadinophysis (Dinophyceae: Dinophysales) en la bahía de Buenaventura y el Parque Nacional Natural Uramba- PNN Uramba en Bahía Málaga del Pacífico colombiano central, se analiza su densidad con los cambios de marea. Se registraron células con contorno subtriangular y reniforme en vista ventral, epiteca pequeña. Aleta sulcal izquierda con tres costillas y la derecha muy reducida o ausente, presentando tamaño promedio 43.1 μm de longitud total y 25.0 𝜇m de ancho total, la densidad del género se analizó bajo cuatro factores, la marea alta y la marea baja en la bahía de Buenaventura y en la bahía de Málaga. Se encontraron diferencias significativas entre la densidad en la marea alta y la marea baja para la bahía de Buenaventura, la diferencia entre la marea alta de la bahía de Málaga y la marea baja de la bahía de Buenaventura. Asimismo, se estableció que la distribución de la densidad no tiene ninguna estructura espacial en ninguno de los eventos mareales. Con el presente estudio se registra por primera vez el género de Metadinophysis en el pacífico colombiano, ampliando su distribución a nivel global.

Abstract The dinoflagellate genus Metadinophysis (Dinophyceae Dinophysales) is recorded for the first time in the Buenaventura Bay and Uramba National Natural Park-PNN Uramba in Málaga Bay in the central Colombian Pacific and its density is analyzed with tidal changes. Cells were recorded with subtriangular and reniform outline in ventral view and small epitheca. Left sulcal fin with three ribs and the right one very reduced or absent, presenting average size 43.1 μm total length and 25.0 μm total width, the density of the genus was analyzed under four factors, high tide and low tide in Buenaventura Bay and in Málaga Bay; significant differences were found between the density at high tide and low tide for Buenaventura Bay, the difference between high tide in Malaga Bay and low tide in Buenaventura Bay. Likewise, it was established that the density distribution has no spatial structure in any of the tidal events. With the present study, the genus Metadinophysis is recorded for the first time in the Colombian Pacific, extending its distribution globally.

Resumo Apesar de sua pequena área, a baía do Araçá (AB) possui grande valor cultural, histórico e econômico, e biodiversidade bentônica. Assim, é fundamental monitorar sua saúde ambiental, que inclui conhecer os principais grupos de fitoplâncton e sua variabilidade temporal. As águas rasas da baía do Araçá são continuamente modificadas pela hidrografia complexa do canal de São Sebastião (SSC), desafiando desenhos experimentais convencionais para coleta de fitoplâncton. Aqui relatamos mudanças sazonais na composição do fitoplâncton, em intervalos de 4 a 6 semanas, de setembro de 2013 a agosto de 2014 na baía do Araçá e no SSC, sendo coletadas duas vezes ao dia por três dias consecutivos em cada campanha de amostragem para aumentar a resolução taxonômica. Nosso objetivo foi fornecer um inventário de ocorrência de espécies para auxiliar futuras políticas públicas e gestão ambiental na área. As análises revelaram alta riqueza de espécies e 166 táxons fitoplanctônicos diferentes. Diatomáceas e dinoflagelados foram numericamente dominantes, mas a ocorrência de táxons mudou acentuadamente entre observações. As diatomáceas do gênero Pseudo-nitzschia foram abundantes durante a primavera e o verão concomitantemente às assinaturas da Água Central do Atlântico Sul no CSS, enquanto Thalassiosira ocorreu durante períodos de salinidade relativamente mais baixa. O inventário demonstrou várias espécies potencialmente nocivas de microalgas e cianobactérias, sugerindo fortemente investimentos para programas de monitoramento nesta área que vem registrando aumento populacional contínuo. AB (AB cultural econômico bentônica Assim temporal SSC , (SSC) semanas 201 taxonômica 16 diferentes dominantes observações Pseudonitzschia Pseudo nitzschia CSS baixa cianobactérias contínuo (SSC 20 1 2

Abstract Despite its small area, Araçá Bay (AB) holds cultural, historical, and economic value and displays great benthic biodiversity. Thus, it is crucial to monitor its environmental health, including knowing the main groups of phytoplankton and their temporal variability. The shallow waters of Araçá Bay are continuously modified by the complex hydrography of the adjacent São Sebastião channel (SSC), challenging standard experimental designs for phytoplankton collection. Here we report changes in phytoplankton composition at intervals of five to six weeks from September 2013 to August 2014 in both Araçá Bay and SSC. Samples were collected twice daily for three consecutive days to increase taxonomic resolution. Our goal was to provide an inventory of species occurrences to aid future public policies and environmental management of the area. Analyses revealed high species richness and 166 different phytoplankton taxa. Diatoms and dinoflagellates were always numerically dominant, but taxa occurrence changed markedly. Diatoms of the genera Pseudo-nitzschia were abundant during spring and summer concurrently to signatures of South Atlantic Central Water in the SSC, while Thalassiosira occurred when waters displayed relatively lower salinity. The inventory demonstrated several potentially harmful species of microalgae and cyanobacteria, strongly suggesting investments in monitoring programs in this area that currently experience an increase in population. AB (AB cultural historical biodiversity Thus health variability SSC , (SSC) collection 201 resolution 16 dominant markedly Pseudonitzschia Pseudo nitzschia salinity cyanobacteria population (SSC 20 1 2

Resumen: Antecedentes y Objetivos: El orden Gymnodiniales está compuesto por 11 familias, 63 géneros y 641 especies taxonómicamente válidas. Estos dinoflagelados se caracterizan por presentar una pared celular muy frágil. Además, algunas especies pueden llegar a producir potentes toxinas e incluso tienen la capacidad para formar grandes florecimientos. Los estudios enfocados en conocer la diversidad de este grupo, en el caso de las costas del Pacífico Mexicano, siguen siendo limitados, a pesar de la importancia económica, social y ecológica de estos microorganismos. Por lo tanto, el objetivo de este estudio fue realizar un listado florístico a partir de una revisión bibliográfica, que integre únicamente a los registros respaldados por micrografías, para conocer la diversidad de dinoflagelados atecados del orden Gymnodiniales presentes en el Pacífico Mexicano, con énfasis en aquellos formadores de florecimientos algales nocivos. Métodos: La búsqueda de información se realizó en publicaciones (artículos y capítulos de libros), desde el primer registro (1943) hasta la actualidad (noviembre 2022). Cada registro fue confirmado únicamente mediante la existencia de micrografías ópticas y de electrónicas de barrido. Resultados clave: El Pacífico Mexicano está conformado por 11 estados costeros, donde actualmente se tiene reportada la presencia de 10 familias, 31 géneros y 103 especies (16% del total de las registradas a nivel mundial) para el orden Gymnodiniales. De las 11 familias que conforman a este orden, la familia Gymnodiniaceae agrupó 29% del total de especies registradas para el Pacífico Mexicano, donde los géneros Gymnodinium y Gyrodinium presentaron el mayor número de especies. Conclusiones: La evidencia presentada en este estudio demostró que existe una baja diversidad para este orden en el Pacífico Mexicano, por lo que es necesario implementar un mayor esfuerzo de muestreo, además de incursionar en diferentes herramientas moleculares que permitan obtener una mejor aproximación a la diversidad alfa en las costas mexicanas.

Abstract: Background and Aims: The order Gymnodiniales is composed of 11 families, 63 genera and 641 taxonomically valid species. These dinoflagellates are characterized by having a very fragile cell wall. In addition, some species can produce phycotoxins and form dense blooms. In the case of the Mexican Pacific coast, studies focused on knowing the diversity of this group are still limited, despite the economic, social, and ecological importance of these microorganisms. Therefore, the objective of this study was to make a floristic list from a bibliographical review, integrating only the records supported by micrographs, to know the diversity of athecate dinoflagellates of the order Gymnodiniales present in the Mexican Pacific Ocean, with emphasis on those that form harmful algal blooms. Methods: The search for information was carried out in publications (articles and book chapters), from the first record (1943) to the present (November 2022). Each record was confirmed only by the existence of optical and scanning electron micrographs. Key results: The Mexican Pacific is made up of 11 coastal states, where the presence of 10 families, 31 genera and 103 species (which represents 16% of the total number of species recorded worldwide) is currently reported for the order Gymnodiniales. Of the 11 families that make up this order, the Gymnodiniaceae family grouped 29% of the total number of species recorded for the Mexican Pacific, where the genera Gymnodinium and Gyrodinium presented the largest number of species. Conclusions: The evidence presented in this study showed that there is a low diversity for this order in the Mexican Pacific, so it is necessary to implement a greater sampling effort, in addition to venturing into different molecular tools that allow obtaining a better approximation of the diversity in the Mexican coasts.

Abstract The present work characterizes the water quality during the culture of shrimp Litopenaeus vannamei in an open system, using fresh well water (0.3 ‰ salinity). The water extracted from the subsoil contained 0.3 ‰ salinity, 0.0115 mg L-1 phosphate (P-PO4), 0.003 mg L-1 nitrite (N-NO2), 0.029 mg L-1 nitrate (N-NO3), < 0.010 mg L-1 ammonium N-NH4, 300 mg L-1 total hardness and 210 mg L-1 alkalinity. The study includes the analysis of the acclimation process of 20-day-old L. vannamei post-larvae and its further development in an open culture system. During acclimation, ammonium concentration increased from non-detect to 1.2 mg L-1 on the second day, and then to 1.5 mg L-1 on the eighth day. Survival of post-larvae upon reaching the freshwater point was 51 %. During 8 weeks of culture in the 2 earthen ponds, the nutrient concentration fluctuated between 0.01 - 0.03 mg L-1 for nitrite, 0.02 - 0.03 for nitrate, 0.07 - 0.09 for ammonium and 0.19 - 0.21 mg L-1 for phosphate. The most representative phytoplankton groups were chlorophyte, diatoms, dinoflagellates and euglenoids, with about 50.6, 25, 14 and 9.2 %, respectively in average for both ponds. The cyanophyte group was represented in the 1% of the phytoplankton community. Spirogyra sp. was the most dominant species. The total heterotrophic bacteria concentration was around 1100 CFU mL-1, while Vibrio sp., Pseudomonas sp. and total coliforms reached an average concentration of 47, 72 CFU mL-1, and 59 CFU/mL-1 respectively. The average weekly growth of L. vannamei was 0.9 g, survival was 45.9 %, and production was around 1088 kg/ha. The nature of the well water in southern Ecuador provides the necessary nutrients for the cultivation of L. vannamei shrimp at extremely low salinity.

Resumen El presente trabajo caracteriza la calidad del agua durante el cultivo del camarón Litopenaeus vannamei en un sistema abierto, con el uso de agua dulce de pozo (0.3 ‰ salinidad). El agua subterránea contenía 0.3 ‰ de salinidad, 0.0115 mg L-1 de fosfato (P-PO4), 0.003 mg L-1 de nitrito (N-NO2), 0.029 mg L-1 de nitrato (N-NO3), < 0.010 mg L-1 de amonio N-NH4, 300 mg L-1 de dureza total y 210 mg L-1 de alcalinidad. El estudio comprende el análisis del proceso de aclimatación de post-larvas de L. vannamei de 20 días de edad y posterior desarrollo en un sistema abierto de cultivo. Durante la aclimatación la concentración de amonio se incrementó desde no detectada a 1.2 mg L-1 al segundo día, y luego a 1.5 mg L-1 al octavo día. La supervivencia de post-larvas al llegar al punto de agua dulce fue del 51 %. Durante 8 semanas de cultivo en los 2 estanques de tierra, la concentración de nutrientes fluctuó entre de 0.01 - 0.03 mg L-1 para nitrito, 0.02 - 0.03 para nitrato, 0.07 - 0.09 para amonio y 0.19 - 0.21 mg L-1 para fosfato. Los grupos fitoplanctónicos más representativos fueron las clorofitas, diatomeas, dinoflagelados y euglenoideos, con alrededor del 50.6, 25, 14 and 9.2 %, respectivamente en promedio para los dos estanques. El grupo de las cianofitas estuvo representado en el 1% de la comunidad de fitoplancton. Spirogyra sp., fue la especie más dominante. La concentración total de bacterias heterótrofas estuvo alrededor de 1100 UFC mL-1, mientras que Vibrio sp., Pseudomonas sp., y coliformes totales, alcanzaron una concentración promedio de 47, 72 UFC mL-1, y 59 UFC/mL-1 respectivamente. El crecimiento promedio semanal de L. vannamei fue de 0.9 g, la supervivencia de 45.9 %, y una producción alrededor de 1088 kg/ha. La naturaleza del agua de pozo en el Sur del Ecuador dispone de los nutrientes necesarios para el cultivo del camarón L vannamei a extrema baja salinidad.

Resumen Antecedentes. Los Dinoflagelados (Dinoflagellata) se reconocen por los caracteres morfológicos de la cubierta celular específica llamada amphiesma. Este complejo ha presentado ventajas para la descripción de muchas especies; sin embargo, hay otras tantas cuya información morfológica básica es escasa o para la cual no se ha llegado a un consenso respecto a cuestiones nomenclaturales. Un ejemplo de esta problemática es el caso de Durinskia balticaCarty & Cox 1986, nombre asociado con un dinoflagelado que ha tenido problemas de circunscripción y posición sistemática debido a que ha pasado por múltiples cambios de nombre asociados a una misma morfología pasando por cuatro géneros distintos )Glenodinium, Peridinium, Peridiniopsis y Durinskia) desde su primera descripción. Objetivos. El objetivo de este trabajo fue hacer una revisión histórica de los caracteres que se han utilizado en la descripción de especies de Durinskia para identificar las discrepancias taxonómicas por las que ha pasado el género. Métodos. Se reunió cronológicamente la información bibliográfica sobre Durinskia y los registros que ha tenido alrededor del mundo. Se compararon los criterios utilizados para separar las especies. Resultados. En dos cuadros comparativos sobre la historia taxonómica de D. baltica y especies relacionadas se presentaron y revisaron de manera crítica los caracteres morfológicos y ambientales utilizados y los puntos clave en los criterios para circunscribir a esta especie. Conclusiones. Con el estado del conocimiento actual no es posible resolver si D. baltica es una especie exclusiva de agua dulce o también es habitante de ambientes marinos.

Abstract Background. Dinoflagellates (Dinoflagellata) are recognized by the morphological characteristics of their specific cell cover called amphiesma. This complex has presented advantages for the description of many species, however, there are many others whose basic morphological information is scarce, or for which no consensus has been reached regarding nomenclatural issues. An example of this problem is the case of Durinskia balticaCarty & Cox 1986, a name associated with a dinoflagellate that has had circumscription and systematic position problems because it has undergone multiple name changes associated with its morphology, passing through four different genera (Glenodinium, Peridinium, Peridiniopsis and Durinskia) since its first description. Goals. The objective of this work was to make a historical review of the characters that have been used in the description of species of Durinskia to identify the taxonomic discrepancies that the genus has experienced. Methods. Bibliographical information on Durinskia and its records worldwide were compiled. The criteria used to separate the species were compared. Results. In two comparative tables on the taxonomic history of D. baltica and related species, the morphological and environmental characters used, and the key points in the criteria to circumscribe this species are presented and critically reviewed. Conclusions. With the current state of knowledge, it is not possible to resolve whether D. baltica is an exclusively freshwater species or if it also inhabit marine environments.

Resumen Antecedentes. Ortega en 1984 reportó el primer inventario de dinoflagelados de México. A partir de entonces se han realizado varios inventarios sobre estos organismos. Sin embargo, el estudio de los dinoflagelados es aún incipiente debido a la fragilidad y pequeño tamaño de estos organismos. Actualmente, existen más herramientas para su estudio, que darán más detalle para su conocimiento. Objetivos. Compilación de una lista actualizada de dinoflagelados de agua dulce de México hasta 2022. Métodos. Se realizó una búsqueda bibliográfica consultando informes y publicaciones impresas y electrónicas disponibles en los centros de documentación universitarios, así como revisando las bases de datos especializadas AlgaeBase y bdLACET. Resultados. Se han registrado un total de 87 especies y taxones infraespecíficos agrupados en 25 géneros, 18 familias y nueve órdenes. La clasificación taxonómica se hizo con base en el sistema de Moestrup & Calado de 2018. Los nombres se actualizaron según AlgaebBase. Ceratium hirundinella, Gymnodinium palustre, Gymnodinium sp. y Peridinium sp. fueron las especies más frecuentes. Michoacán, Estado de México, Ciudad de México y Oaxaca fueron los estados más estudiados. Y los ambientes más comunes fueron lagos, lagunas y represas. Conclusiones. El número de taxones se incrementó desde el 2004 hasta esta fecha pero no de manera notable como se esperaba, muy probablemente esto se debe porque México actualmente carece del personal y el presupuesto para realizar este trabajo, para ampliar la cobertura geográfica y para la aplicación de microscopía electrónica y de biología molecular, técnicas necesarias para análisis más precisos.

Abstract Background. Since 1984, Ortega and several researchers have documented the presence of dinoflagellates in Mexico in reports and inventories to attain an overview of the biodiversity of this and other algal groups. However, their study is still incipient because of the fragility and small cell size of these organisms. Currently, there are more tools for their study, but precisely for this reason, detailed studies are just beginning. Goals. Compilation of an updated list of freshwater dinoflagellates of Mexico up to 2022. Methods. A bibliographic search was carried out by consulting reports and printed and electronic publications available at university documentation centers, as well as by reviewing the specialized databases AlgaeBase and bdLACET. Results. A total of 87 species and infraspecific taxa grouped into 25 genera,18 families and 9 orders have been recorded. The taxonomic classification was based on the system by Moestrup & Calado (2018). The names were updated according to AlgaebBase. Ceratium hiundinella, Gymnodinium palustre, Gymnodinium sp. and Peridinium sp. were the most frequently occurring species. The states of Michoacan, State of Mexico, Mexico City and Oaxaca were the most studied, and the most common environments were lakes, lagoons, and dams. Conclusions. Despite the expected notable increase in reported taxa from 2004 to date, this is likely not a complete list because Mexico presently lacks the personnel and budget for this work, for the expansion of geographic coverage and for the application of electron microscopy and molecular biology techniques necessary for more precise analyses.

Resumen Antecedentes: Los estudios sobre dinoflagelados bentónicos marinos (DBM) en México comenzaron en 1942 en la región oceánica de Oaxaca, basados en muestras de la columna de agua. En diez estados costeros mexicanos se han recolectado muestras de epibentos y plancton, se han cultivado especies, y se han realizado estudios de campo y de laboratorio. Objetivos: Revisar el estado actual de los estudios sobre DBM en aguas mexicanas para evaluar los riegos posibles en un futuro. Métodos: Se analizó la literatura disponible sobre DBM en México, publicada desde 1942 hasta 2022. Resultados: Se presenta una revisión de los estudios sobre DBM subdividida en cuatro secciones: (1) diversidad taxonómica (morfológica y molecular), (2) toxigenicidad y vectores de ficotoxinas de origen bentónico, (3) toxicidad y (4) interacciones entre especies. Se presenta un mapa de la ubicación de las poblaciones estudiadas de DBM y una lista de estudios taxonómicos y ecológicos sobre DBM en México. Se proporciona una lista de ca. 60 especies, principalmente de Prorocentrum, seguidas en cantidad por los géneros Amphidinium, Gambierdiscus, Ostreopsis, Coolia y Sinophysis. Esta lista está acompañada de imágenes de microscopía electrónica de barrido de 15 especies. Se ha añadido una tabla de referencia sobre especies toxigénicas reportadas y los respectivos síndromes asociados a estas. Conclusiones: Los estudios sobre DBM en México se han incrementado lentamente, probablemente debido a un mayor número de cepas en cultivo y por colaboración internacional. Los vínculos confirmados entre especies asociadas con florecimientos algales nocivos bentónicos y la etiología de los síndromes tóxicos son aún escasos en México.

Abstract Background: Mexican studies on marine benthic dinoflagellates (MBD) began in 1942 from the offshore region of Oaxaca, based on water column samples. Subsequently, in ten Mexican maritime states, both epibenthos and plankton samples have been collected, species have been cultured, and field and laboratory studies have been carried out. Goals: The objective of this contribution is to review the studies on MBD in Mexican waters for current status and future risk assessment. Methods: Available literature on MBD from Mexico published from 1942 to 2022 was analyzed. Results: A review of the studies on MBD is presented herein, subdivided into four sections: (1) taxonomic diversity (morphological and molecular), (2) benthic phycotoxin vectors and toxigenicity, (3) toxicity and (4) species interactions. A map of the location of field populations of MBD and a reference list of taxonomic and ecological studies on MBD in Mexico is provided. A taxonomic list of ca. 60 species, mainly of Prorocentrum, followed in number by Amphidinium, Gambierdiscus, Ostreopsis, Coolia, and Sinophysis is presented. This list is accompanied by scanning electron microscopic images of 15 species. Knowledge of the toxigenicity of MBD is scarce, hence a reference table of known toxigenic species in Mexico and their respective associated syndromes is included. Conclusions: Studies on MBD in Mexico have slowly increased, probably due to the availability of a greater number of cultured strains, as well as to more extensive international collaborations. Confirmed links between benthic harmful algal bloom species and events associated with the etiology of toxic syndromes are rarely known in Mexico.

Resumo O presente estudo relata variações sazonais e espaciais na diversidade, na distribuição e na abundância de dinoflegelados e indica a presença de espécies de HAB nas águas do Paquistão. Um total de 179 táxons, registrados nesse estudo de águas offshore e próximas à costa, pertence a 41 gêneros em 26 famílias e 10 ordens. A alta contagem de espécies (149 espécies) foi registrada na estação offshore da Ilha de Manora (MI-1) e 105 spp., 109 spp. e 115 spp. foram encontrados na estação offshore da vila de Mubarak (MV-1), Manora perto da estação costeira (MI- 2) e estação próxima à costa da Vila de Mubarak (MV-2), respectivamente. Tripos furca foi a espécie dominante e de ocorrência frequente (> 1 x103 a > 25 x103 células L-1 da costa e > 1x 105 células Ll de estações próximas à costa), além de Alexandrium catenella menos abundante, Alexandrium sp., Alexandrium minutum e Prorocentrum micans (> 103 a 25x 103 células/L). Outras 44 espécies ocorreram em números relativamente baixos (< 103 células L-1). Setenta espécies foram encontradas durante o período de estudo em todas as quatro estações. Foi registrado um alto número de espécies em três gêneros (Tripos (38), Protoperidinium (34) e Prorocentrum (20). Potencialmente tóxicos (16 gêneros e 43 espécies) e HAB relacionados (19 gêneros e 30 espécies), táxons de dinoflagelados também foram registrados. A contribuição percentual de dinoflagelados na população fitoplanctônica total geralmente permaneceu abaixo de 20%, exceto em alguns casos. As estações da Ilha de Manora tinham índice de Shannon comparativamente mais alto e equitabilidade e índice de dominância ligeiramente mais baixos. O gráfico de PCA mostrou forte correlação positiva entre concentração de clorofila-a e oxigênio dissolvido, número total de fitoplânctons e dinoflagelados.

Abstract The present study reports on seasonal and spatial variations in diversity, distribution and abundance of dinoflegellates and indicates the presence of HAB species in Pakistan waters. A total of 179 taxa, recorded in this study from offshore and near-shore waters, belong to 41 genera in 26 families and 10 orders. The high species count (149 species) was recorded from Manora Island offshore station (MI-1) and 105 spp, 109 spp and 115 spp were encountered from the Mubarak village offshore station (MV-1), Manora near shore station (MI-2) and Mubarak Village near-shore station (MV-2) respectively. Tripos furca was the dominant and frequently occurring species (> 1 x103 to > 25 x103 cells L-1 from coastal and >1x 105 cells L-l from near-shore stations) in addition to less abundant Alexandrium catenella, Alexandrium sp., Alexandrium minutum, and Prorocentrum micans (>103 to 25x 103cells/L). Another 44 species occurred in relatively low numbers (<103 cell L-l). Seventy species were found throughout the study period at all four stations. High number of species in three genera (Tripos (38), Protoperidinium (34) and Prorocentrum (20) was recorded. Potently toxic (16 genera 43 species) and HAB related (19 genera and 30 species) dinoflagellate taxa were also recorded. The percent contribution of dinoflagellates in total phytoplankton population generally remained below 20% except for a few instances. Manora Island stations had comparatively higher Shannon index and equitability and slightly lower dominance index. The PCA plot showed strong positive correlation among chlorophyll-a concentration, dissolved oxygen, total number of phytoplankton and dinoflagellates.

Resumo Objetivo Objetivamos caracterizar a estrutura da comunidade fitoplanctônica e identificar os principais fatores ambientais que impulsionam a comunidade em cinco reservatórios construídos na região do alto rio Paraná. Métodos O fitoplâncton e as variáveis ambientais foram coletados na região lacustre do reservatório, entre novembro de 2013 e novembro de 2014, com intervalo entre as coletas de 3 a 6 meses. A riqueza e a biomassa da comunidade fitoplanctônica foram utilizadas como resposta à variabilidade ambiental espacial e temporal dos reservatórios. Os dados das variáveis ambientais foram analisados por meio de uma Análise de Componentes Principais (PCA). Foram realizadas Análises de Escalonamento Multidimensional Não-Métrico (NMDS) aos dados de riqueza e biomassa da comunidade fitoplanctônica. Resultados Identificamos 80 táxons distribuídos em 11 classes, dos quais Cyanobacteria e Chlorophyceae foram os mais representados. Não observamos variação temporal significativa para variáveis ambientais ou atributos da comunidade fitoplanctônica, o que pode estar relacionado à prolongada estiagem neste período no sudeste brasileiro. Os maiores valores de riqueza e biomassa fitoplanctônica foram encontradas em Três Irmãos (Rio Tietê), reservatório localizado na bacia mais antropizada do país. Cianobactérias e dinoflagelados dominaram a biomassa em todos os reservatórios durante o período estudado. Os reservatórios de Ilha Solteira, Jupiá e Porto Primavera apresentaram tendência de diminuição nos valores de riqueza e biomassa fitoplanctônica, sendo que os reservatórios construídos em série no rio Paraná provavelmente possuem forte interdependência, de acordo com o conceito do CRCC. Conclusões A variação espacial dos atributos fitoplanctônicos foi influenciada principalmente pela posição ocupada pelo reservatório na bacia hidrográfica, tempo de retenção de água (TR) e concentrações de nutrientes em cada reservatório.

Abstract Aim We aimed to characterize the structure of the phytoplankton community and identify the main environmental factors driving the community in five reservoirs constructed in the region of the high Paraná River. Methods The phytoplankton and environmental variables were collected at the lacustrine region of the reservoir, between November 2013 and November 2014, with interval between collections ranged from 3 to 6 months. The richness and biomass of the phytoplankton community were measured as a response to the spatial and temporal environmental variability. Data from environmental variables was analyzed by Principal Component Analysis (PCA). Non-Metric Multidimensional Scaling Analyzes (NMDS) were performed on the richness and biomass data of the phytoplankton community. Results We identified 80 taxa distributed in 11 taxonomic classes, from which Cyanobacteria and Chlorophyceae were best represented. We did not observe significant temporal variation for either environmental variables or attributes of the phytoplankton community, which may be related to the prolonged drought in this period in the Brazilian Southwest. Higher phytoplankton richness and biomass were found in the Três Irmãos (Tiete River), reservoir located in the most anthropized basin in the country. Cyanobacteria and dinoflagellates dominated the biomass in all reservoirs during the studied period. The Ilha Solteira, Jupiá and Porto Primavera reservoirs showed a tendency to decrease in the values of phytoplankton richness and biomass, and the reservoirs built in series in the Paraná River probably have strong interdependence, according to the CRCC concept. Conclusions Spatial variation in phytoplankton attributes was influenced mainly by the position occupied by the reservoir in the hydrographic basin, water retention time (RT) and nutrient concentrations in each reservoir.

Resumo Scrippsiella acuminata é um complexo de espécies que pode causar condições anóxicas na coluna d’água durante florações. Este estudo teve como objetivo analisar a ocorrência e distribuição de Scrippsiella cf. acuminata ao longo do gradiente estuarino do rio Paraguaçu, a partir de coletas bimestrais (março de 2018 a março de 2019) realizadas em 12 pontos amostrais. Variáveis ambientais foram medidas in situ, e amostras de água foram coletadas para análise de nutrientes inorgânicos dissolvidos e densidade de células fitoplanctônicas. Em cada ponto, as amostras foram coletadas para análise da composição das espécies e preservadas com formaldeído com concentração final de 4%. S. cf. acuminata ocorreu em todo o gradiente estuarino (salinidade 0,1–38,9), exceto em julho, coincidindo com as menores concentrações de nutrientes inorgânicos dissolvidos. A densidade celular variou entre 20 células L-1 (janeiro de 2019) e 1,8 × 106 células L-1 (março de 2018); neste último, ocorreu uma floração em condições de baixa salinidade (5,7) e a maior concentração de nutrientes inorgânicos dissolvidos registrada para o estudo. A densidade celular (1,7 × 105 L-1) aumentou novamente em novembro de 2018. Nenhum dos eventos teve efeitos prejudiciais no sistema estuarino. Este estudo permitiu-nos compreender melhor os padrões de distribuição de S. cf. acuminata considerando as características ambientais que podem favorecer seu desenvolvimento.

Abstract Scrippsiella acuminata is a species complex that can cause anoxic conditions in the water column during blooms. This study aimed to analyze the occurrence and distribution of Scrippsiella cf. acuminata along the estuarine gradient of Paraguaçu River, from bimonthly sampling (March 2018 to March 2019) performed at 12 sampling points. Environmental variables were measured in situ, and water samples were collected for analysis of dissolved inorganic nutrients and phytoplankton cell density. At each point, samples were collected for analysis of species composition and preserved with formaldehyde at a final concentration of 4%. S. cf. acuminata occurred throughout the estuarine gradient (salinity 0.1–38.9), except in July, coinciding with the lowest concentrations of dissolved inorganic nutrients. Cell density varied between 20 cel L-1 (January 2019) and 1.8 × 106 cell L-1 (March 2018); in the latter, the species bloomed under conditions of low salinity (5.7) and the highest dissolved inorganic nutrient concentration recorded in the study. Cell density (1.7 × 105 L-1) increased in November 2018. Neither event had any detrimental effects on the estuarine system. This study allowed us to better understand the distribution patterns of S. cf. acuminata considering the environmental characteristics that can favor its development.

Resumen Introducción y objetivos : Los dinoflagelados planctónicos son de gran relevancia en los ecosistemas marinos. Mientras que algunas especies suelen forman floraciones y ser componentes conspicuos del fitoplancton, otras se encuentran en abundancias muy bajas, lo cual hace difícil su detección. Aquí analizamos la composición y abundancia de dinoflagelados en cinco expediciones oceanográficas realizadas en aguas de la plataforma continental y del talud del Mar Argentino. M&M : La abundancia se estimó con microscopio invertido (método Utermohl) y se utilizó microscopía óptica y electrónica de barrido para la identificación específica. Resultados : Nos enfocamos en la ocurrencia de siete dinoflagelados que previamente han sido poco documentados en ambientes marinos de todo el mundo: Dinophysis microstrigiliformis; Gyrodinium sp.; Karlodinium elegans; Oxytoxum laticeps; Peridiniella danica; Peridiniella globosa y Prorocentrum nux. Esta última especie y K. elegans se observan por primera vez en el campo desde su descripción basada en cultivos celulares. Si bien la mayoría de las especies se detectaron en abundancias bajas o moderadas, P. nux, el Prorocentrum más pequeño, alcanzó 82.000 células L-1 en aguas del talud. Células pequeñas de Gyrodinium sp. (11,5 jm de largo y 8,7 jm de ancho), con un una distribución restringida a las aguas del talud durante la primavera, no pudieron ser asignadas con precisión a nivel específico. Conclusiones : Este estudio contribuye al conocimiento de la diversidad de dinoflagelados en el Mar Argentino y la distribución mundial de especies poco conocidas.

Summary Background and aims : Planktonic dinoflagellates have a great ecological significance in marine environments. While some dinoflagellate species commonly reach bloom concentrations and are thus conspicuous components of marine phytoplankton, others occur in very low abundances which make them difficult to detect in field studies. Here we analyzed dinoflagellate composition and abundance in five oceanographic expeditions carried out in continental shelf and slope waters of the Argentine Sea. M&M : Plankton abundance was estimated by the Utermohl method, using inverted microscopy, whereas further optical and scanning electron microscopy was applied for the identification of dinoflagellate species. Results : We focused on the occurrence of seven dinoflagellates that have been previously poorly documented or overlooked in marine environments worldwide: Dinophysis microstrigiliformis; Gyrodinium sp.; Karlodinium elegans; Oxytoxum laticeps; Peridiniella danica; Peridiniella globosa and Prorocentrum nux. The latest and K. elegans are observed for the first time in field conditions after their original descriptions based on cell cultures. While most species were detected in low or moderate abundances, P. nux, which is the smallest Prorocentrum species, reached 82,000 cells L-1 in slope waters. Very small Gyrodinium cells (11.5 |jm long; 8.7 |jm wide) with a distribution restricted to slope waters during spring, were not possible to be accurately assigned to a species. Conclusions : This study contributes to the understanding of dinoflagellate diversity in the Argentine Sea and the worldwide distribution of little known species.