Distribution and abundance of dinoflagellates from the coastal waters of Karachi, Pakistan, northern part of the Arabian Sea / Distribuição e abundância de dinoflagelados nas águas costeiras de Karachi, Paquistão, parte norte do Mar da Arábia

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-¹ 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-¹). 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.

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.

First record of Ceratium furcoides (Dinophyta), an invasive species, in a temporary high-altitude lake in the Iron Quadrangle (MG, Southeast Brazil) / Primeiro registro de Ceratium furcoides (Dinophyta), uma espécie invasora, em um lago temporário de alta altitude no Quadrilátero Ferrífero (MG, Sudeste do Brasil)

Dinoflagellates of the genus Ceratium are generally marine organisms, but rare occurrences in freshwater have been observed in Brazil. In this paper we are recording for the first time the presence of Ceratium furcoides, an invasive species, in a shallow, natural intermittent pool formed at a high-altitude at the southern end of the Iron Quadrangle, an iron-mining district of Minas Gerais State (Southeast Brazil). Samples were collected in October and November of 2010 (rainy period). The population density of this organism observed in Lagoa Seca (“Dry Pool”) was very low, at most 4 ind L–1. Mountain lakes are extremely vulnerable to atmospheric deposition of organisms, making them valuable witnesses both of the many forms of impact arising from human activities and of the extended global connections that facilitate the dispersion and introduction of new species over great distances. Studies on the population dynamics of C. furcoides in natural tropical systems are still rare and very recent to the brazilian scenario and hence the monitoring of its dynamics and the potential impact on aquatic communities of its becoming established are essential to an understanding of the process of bioinvasion by this species.

Dinoflagelados do gênero Ceratium são principalmente marinhos, porém existem raras ocorrências em água doce no Brasil. Neste estudo registramos pela primeira vez a ocorrência de Ceratium furcoides, uma espécie invasora em um lago altitudinal natural raso localizado na porção sul do Quadrilátero Ferrífero, uma área de extração mineral no estado de Minas Gerais. As coletas foram realizadas nos meses de outubro e novembro de 2010 (período chuvoso). As densidades observadas para C. furcoides na Lagoa Seca foram muito baixas, com máximo de 4 ind L–1. Lagos de altitude são altamente vulneráveis à deposição atmosférica, o que os torna importantes testemunhos não só dos múltiplos impactos derivados de atividades humanas, mas também das extensas conexões globais, que acabam por facilitar a dispersão e introdução de espécies. Estudos sobre a dinâmica de C. furcoides em sistemas tropicais naturais ainda são escassos e por isso, o monitoramento de sua dinâmica e dos impactos potenciais em comunidades aquáticas a partir do seu estabelecimento, torna-se fundamental para o entendimento dos processos relacionados à bioinvasão desta espécie.

The importance of protozoan bacterivory in a subtropical environment (Lobo-Broa Reservoir, SP, Brazil) / A importância da bacterivoria por protozoários em um ambiente subtropical (Reservatório do Lobo-Broa, SP, Brasil)

This study evaluated the importance of heterotrophic nanoflagellates (HNF) and ciliates bacterivory in a mesotrophic subtropical environment (Lobo-Broa Reservoir, Brazil) by the quantification of their ingestion rates. The in situ experiments using fluorescently labelled bacteria (FLB) were carried out bimonthly over one year (three surveys in the dry season and three in the rainy one) at the sub-surface of two sampling points that have different trophic degrees. The ingestion rates for both ciliates and HNF were higher in the meso-eutrophic region (point 2) due to the higher water temperatures, which accelerate the metabolism of protozoans and the higher bacteria densities. Concerning total protozoan bacterivory, the HNF had the greatest grazing impact on bacterial community, especially the HNF <5µm. The data showed that HNF grazing, in addition to regulating the bacteria abundance, also induced changes to the bacterial community structure, such as increasing size and numbers of bacterial filaments. The ciliates were also important to the system bacterivory, especially in point 2, where there were high densities and ingestion rates. The protozoan bottom-up control was more important in the dry season and the top-down control was more important in the rainy season, so, these two forces are equally important to the bacterial abundance regulation in this reservoir in an annual basis.

Este estudo avaliou a importância da bacterivoria por nanoflagelados heterotróficos (NFH) e ciliados em um ambiente subtropical mesotrófico (Reservatório do Lobo-Broa, Brasil) pela quantificação de suas taxas de ingestão. Os experimentos in situ utilizando bactérias marcadas por fluorescência (FLB) foram realizados bimestralmente durante um ano (três estudos no período seco e três no período chuvoso) na superfície de dois pontos de coleta que apresentam graus de trofia diferentes. As taxas de ingestão, tanto para os ciliados quanto para os NHF, foram maiores no ponto 2 (P2) devido provavelmente as maiores temperaturas da água, que aceleram o metabolismo dos protozoários, e as maiores densidades de bactérias. Em relação à bacterivoria total por protozoários, as populações de NFH causaram maior impacto de predação sobre a comunidade bacteriana do reservatório, principalmente os NFH menores que 5µm. Os dados indicaram que a predação por NFH, além de regular a abundância de bactérias, provavelmente também induziu modificações na estrutura da comunidade bacteriana, como o aumento do tamanho e da quantidade de filamentos bacterianos. Os ciliados também contribuíram significativamente para a bacterivoria no sistema, principalmente no P2, onde apresentaram altas densidades e taxas de ingestão. O controle bottom-up teve maior importância no período seco e o controle top-down maior importância no período chuvoso, assim, estas duas forças são igualmente importantes na regulação da abundância bacteriana neste reservatório em uma base anual.

New record of Akashiwo sanguinea (Dinophyta) in the tropical estuarine waters of Northeastern Brazil (Western Atlantic) / Novo registro de Akashiwo sanguinea (Dinophyta) em águas estuarinas tropicais do nordeste do Brasil (Atlântico Ocidental)

This study reports the occurrence and the effect of the environmental factors on the spatial and temporal distribution of the dinoflagellate Akashiwo sanguinea (Hirasaka) Hansen & Moestrup in estuarine waters of northeastern Brazil. Samples were collected at seven stations from March 2007 to February 2008 during high tide and low tide, using Van Dorn bottles. The samples were immediately fixed with Lugol and analyzed with the Utermöhl method. Water samples were also collected for the identification of the hydrological characteristics of the area. Akashiwo sanguinea occurred throughout the annual cycle and at all sampling sites with densities ranging between 5 and 410 x 103 cells.L–1. The highest densities were recorded at low tide, especially during the months of the rainy season (July: 210 x 103 cells.L–1; August: 410 x 103 cells.L–1). Density values were within the normal range and blooms were not detected. Despite being common in the area, the species showed preference for sites with high concentrations of orthophosphate and total dissolved phosphorus and with salinity in the mesohaline regime.

Este estudo relata a ocorrência e o efeito dos fatores ambientais na distribuição espacial e temporal do dinoflagelado Akashiwo sanguinea (Hirasaka) Hansen et Moestrup em águas estuarinas do Nordeste do Brasil. As amostras foram coletadas em sete estações, durante o período de março 2007 a fevereiro 2008 durante os regimes de preamar e baixa-mar, com o auxílio de garrafas tipo Van Dorn. As amostras foram imediatamente fixadas com lugol e analisadas pelo método de Utermöhl. Amostras de água foram também coletadas para a identificação das características hidrológicas da área. Akashiwo sanguinea ocorreu em todo o ciclo anual e em todos os locais de coleta com densidade variando de 5 a 410 cells.L–1 x 103, sendo as maiores densidades registradas na baixa-mar, principalmente, durante os meses do período chuvoso (julho 210 cells.L–1 x 103, agosto 410 cells.L–1 x 103). Os valores quantitativos estiveram dentro dos padrões normais, não tendo sido detectados florescimentos com conotações de blooms. Apesar de ser frequente na área, a espécie mostrou preferência pelos locais com maiores concentrações de ortofosfato dissolvido e fósforo total dissolvido e salinidade compreendida no regime mesoalino.

Population fluctuations of Pyrodinium bahamense and Ceratium furca (Dinophyceae) in Laguna Grande, Puerto Rico, and environmental variables associated during a three-year period / Fluctuaciones poblacionales de Pyrodinium bahamense y Ceratium furca (Dinophyceae) en Laguna Grande, Puerto Rico, y variables ambientales asociadas durante un periodo de tres años

Bioluminescent bays and lagoons are unique natural environments and popular tourist attractions. However, the bioluminescence in many of these water bodies has declined, principally due to anthropogenic activities. In the Caribbean, the bioluminescence in these bays and lagoons is mostly produced by the dinoflagellate Pyrodinium bahamense var. bahamense. Laguna Grande is one of the three year-round bioluminescent water bodies in Puerto Rico that are known to remain but P. bahamense var. bahamense density fluctuations have not been studied. In this study we describe water quality parameters and density fluctuations of the most common dinoflagellates in Laguna Grande, P. bahamense var. bahamense and Ceratium furca, over a three-year period. For this, three sampling stations were established in Laguna Grande from which water samples were collected in triplicate and analyzed for temperature, phosphates, nitrates, salinity, water transparency, fluorescence, and dinoflagellate densities, at the water surface and at 2m depth, from May 2003 to May 2006. The results showed a density fluctuation pattern for P. bahamense var. bahamense, where higher densities were observed mainly from April to September, and lower densities from October to February. Density fluctuations of C. furca were more erratic and a repetitive pattern was not observed. Densities of P. bahamense var. bahamense ranged from 0.48 to 90 978 cells/L and densities of C. furca ranged from 0 to 11 200 cells/L. The mean population density throughout the sampling period was significantly higher in P. bahamense var. bahamense (mean=18 958.5 cells/L) than in C. furca (mean=2 601.9 cells/L). Population densities of P. bahamense var. bahamense were negatively correlated with C. furca densities during the first year of sampling; however, they were positively correlated during the third year. Non-significant differences between surface and 2m depth samples were observed for temperature, phosphates, nitrates, salinity, fluorescence, and densities of P. bahamense var. bahamense and C. furca, suggesting a vertically mixed water column. Water transparency was positively correlated with salinity and negatively correlated with fluorescence. Fluorescence was negatively correlated with salinity. The mean population densities of P. bahamense var. bahamense and C. furca observed in this study were within the range of previous reports in other bioluminescent water bodies in Puerto Rico and Florida, USA. In order to conserve the continuous P. bahamense var. bahamense populations in Laguna Grande, as well as its bioluminescence, it is recommended to maintain the existing water flow levels in the 1.5km long inlet/outlet channel; to maintain unpolluted water quality parameters within the bay, the hydrographical basin and adjacent waters, and to preserve mangrove communities within the basin and adjacent areas. Results of this study may help to develop management plans aiming to conserve P. bahamense, its bioluminescence and the lagoon attraction.

Este estudio describe parámetros de calidad de agua y fluctuaciones en la densidad poblacional de Pyrodinium bahamense Plate 1906 y Ceratium furca (Ehrenberg) Claparède & Lachmann 1859, los dos dinoflagelados más abundantes en las bahías y lagunas bioluminiscentes de Puerto Rico, durante un periodo de tres años, en Laguna Grande, Puerto Rico. En P. bahamense se observó un patrón de densidad poblacional, donde se bservaron las densidades más altas mayormente desde abril hasta septiembre y las más bajas desde octubre hasta febrero. En C. furca las fluctuaciones en densidad fueron más erráticas y no se observó un patrón repetitivo. La densidad poblacional promedio de P. bahamense (media=18 958.5 células/L) fue significantemente mayor que la de C. furca (media=2 601.9 células/L). No se encontraron diferencias significantes entre las muestras de superficie y las de 2m de profundidad para temperatura, fosfatos, nitratos, salinidad, fluorescencia, y las densidades de P. bahamense y C. furca, lo que sugiere que la columna de agua está mezclada verticalmente. La densidad poblacional media de P. bahamense y C. furca en Laguna Grande está dentro del rango de las densidades que han sido reportadas para otras lagunas bioluminiscentes en Puerto Rico y Florida, EE.UU.

Primer informe del género Gambierdiscus (Dinophyceae) y otros dinoflagelados bentónicos en el Parque Nacional Isla del Coco, Costa Rica, Pacífico Tropical Oriental / First report of the genus Gambierdiscus (Dinophyceae) and other benthic dinoflagellates from Isla del Coco National Park, Costa Rica, Eastern Tropical Pacific

The Eastern Tropical Pacific is a region reported as free of ciguatera poisoning that causes serious gastrointestinal, neural and cardiovascular problems, even death. But with this study we found a high incidence of benthic microalgae involved in ciguatera poisoning in Isla del Coco National Park (PNIC, from its name in Spanish), Costa Rica. Between 2006 and 2011, during expeditions to PNIC, 420 phytoplankton samples with the interest of finding benthic dinoflagellates involved in the ciguatera poisoning were collected and analyzed. Samples were taken with phytoplankton nets, towed vertically and horizontally or carried by diving, between 5 to 30 m depth, over reef areas, and by direct extraction from benthic macroalgae. We found the dinoflagellates Gambierdiscus spp., Coolia tropicalis, Coolia cf. areolota, Prorocentrum concavum, Prorocentrum compressum, Amphidinium carterae and Ostreopsis siamensis. The quantity of dinoflagellates by macroalgae weight was high, mainly for Gambierdiscus. Ostreopsis and Prorocentrum, the most widely distributed genera throughout the collection sites. Gambierdiscus is a ciguatera producing genus. Two different sizes of Gambierdiscus were found, and comparing our samples with other studies, we conclude that they are different to any previously reported. They possibly represent two new species. Coco Island is an oceanic island and because of its protection status, it is an ideal site for studying the evolution of marine phytoplankton. Also, long-term monitoring is important due to the variety of potentially toxic dinoflagellates living in this marine ecosystem. This is the first study to report benthic dinoflagellates implicated in ciguatera poisoning in other areas of the Eastern Tropical Pacific.

El Pacífico Tropical Oriental se ha indicado como una región de los océanos libre de ciguatera, una intoxicación que causa serios trastornos gastrointestinales, neurológicos y cardiovasculares, en casos extremos, la muerte. Pero con el presente estudio hemos encontrado una incidencia alta de microalgas bénticas involucradas en la producción de ciguatera en el Parque Nacional Isla del Coco (PNIC), Costa Rica. En campañas oceanográficas realizadas entre el 2006 y el 2011 al PNIC se recolectaron 420 muestras de fitoplancton con el interés de encontrar especies de dinoflagelados bentónicos implicados en la producción de ciguatera. Las muestras se tomaron con red de fitoplancton o mediante buceos, entre los 5 y 30 m de profundidad en zonas de arrecife y por extracción directa de macroalgas. Se encontró a los dinoflagelados Gambierdiscus spp., Coolia tropicales, Coolia cf. areolota, Prorocentrum concavum, Prorocentrum compressum, Amphidinium carterae y Ostreopsis siamensis. Se determinó que la cantidad de dinoflagelados por peso de macroalga era elevada, principalmente para el género Gambierdiscus. Los géneros Ostreopsis y Prorocentrum mostraron tener la mayor distribución en los sitios de colecta. Gambierdiscus es un género productor de ciguatera. Se encontraron dos tamaños diferentes de individuos de Gambierdiscus, Comparando los especímenes de Gambierdiscus encontradas con otros estudios, se concluye que son diferentes a las descritas anteriormente, por lo que podría tratarse de especies nuevas, lo que se confirmará con cultivos y análisis moleculares. Al ser la Isla del Coco un sitio oceánico aislado y en estado de conservación, es un sitio ideal para el estudio de la evolución de especies de fitoplancton marino. Además, el monitoreo a largo plazo es muy importante debido a la variedad de dinoflagelados bentónicos potencialmente tóxicos que habitan en este ecosistema marino. Este es el primer estudio donde se da a conocer la incidencia de dinoflagelados bentónicos implicados en ciguatera para el Pacífico Tropical Oriental.

Dinoflagelados (Dinophyta) de los órdenes Prorocentrales y Dinophysiales del Sistema Arrecifal Veracruzano, México

Dinoflagellates (Dinophyta) of orders Dinophysiales and Prorocentrales of the Veracruz Reef System, Mexico. Dinoflagellates are a major taxonomic group in marine phytoplankton communities in terms of diversity and biomass. Some species are also important because they form blooms and/or produce toxins that may cause diverse problems. The composition of planktonic dinoflagellates of the orders Prorocentrales and Dinophysiales, in the Veracruz Reef System, were obtained during the period of October 2006 to January 2007. For this, samples were taken from the surface at 10 stations with net of 30μm mesh, and were analyzed by light and scanning electron microscopy. Each species was described and illustrated, measured and their distribution and ecological data is also given. A total of nine species were found and identified, belonging to four genera: Dinophysis was represented by three species; Prorocentrum by three, Phalacroma by two, and only one species of Ornithocercus was detected. From the samples, four potentially toxin-producer species were found: Dinophysis caudata, D. rapa, Phalacroma rotundata and Prorocentrum micans. The number of species found in this study is low, especially considering the higher numbers observed in other areas of the Gulf of Mexico, where some reports have recorded up to 53 species of the order Dinophysiales and 14 for Prorocentrales. Identification keys for orders, genera and species for the study area are provided with this study. Rev. Biol. Trop. 59 (1): 501-514. Epub 2011 March 01.

Los dinoflagelados son considerados como el grupo más abundante y diverso de microalgas del fitoplancton después de las diatomeas. Esta investigación da a conocer la composición específica de dinoflagelados planctónicos de los ordenes Prorocentrales y Dinophysiales, recolectados mediante arrastres superficiales con red (30μm de luz de malla) en el Sistema Arrecifal Veracruzano (SAV), de las costas de Veracruz, México, en el período octubre 2006 a enero2007. Para el análisis del material se utilizaron microscopios de luz y electrónico de barrido. Se identificaron 9 especies de cuatro géneros: Dinophysis estuvo representado por 3 especies, al igual que Prorocentrum, dos de Phalacroma y una de Ornithocercus. Se presentan claves para identificación de los órdenes, géneros y especies de dinoflagelados, asimismo se describe e ilustra cada especie, incluyendo datos morfométricos y se menciona la distribución de las mismas. Dinophysis caudata, D. rapa, D. ovum y Phalacroma rotundata se han documentado como especies potencialmente productoras de toxinas. La riqueza de especies en el SAV se considera muy baja, especialmente considerando mayores riquezas en otras zonas del Golfo de México, como el sur del Golfo de México, donde se han listado 53 especies del orden Dinophysiales y 14 especies de Prorocentrales.

Proliferaciones algales 2000-2001 en Bahía de Banderas, México según el sensor SeaWiFS

Algal blooms at Banderas Bay, México (2000-2001), from SeaWiFS-sensor-data. Algal blooms for the period of 2000 and 2001 at Banderas Bay, México, were analyzed from SeaWiFS-ocean-color-sensor derived information. These events were related with the maximum chlorophyll week anomalies (ASi; a proxy variable constructed for the analysis of chlorophyll temporal variation in the bay). The winter-spring blooms were multispecific, while the summer-fall blooms were monospecific. Two proposals are made: 1) Winter-spring blooms are strongly related with mesoescale processes, due to their apparent temporal synchrony with the high chlorophyll levels in the coastal region from Sinaloa to Jalisco states; 2) Cochlodinium polykrikoides (Margalef 1961) blooms during the summer-fall periods could be induced by local conditions and the influence of previous events on the ecosystem. Rev. Biol. Trop. 56 (4): 1653-1664. Epub 2008 December 12.

Se analizaron las proliferaciones algales ocurridas en Bahía de Banderas, México, durante los años 2000 y 2001 a partir de información derivada del sensor de color del océano SeaWiFS. Estos eventos estuvieron relacionados con los máximos niveles de Anomalías Semanales de Clorofila’ (As i; variable construida para analizar la variación temporal de la clorofila dentro de la bahía). Las proliferaciones ocurridas en los periodos invierno-primavera fueron multiespecíficos, mientras que en verano-otoño fueron dominadas por una sola especie. Se plantean dos propuestas: 1) las proliferaciones algales de invierno-primavera están fuertemente relacionadas a procesos de mesoescala dada su aparente sincronía temporal con altos niveles de clorofila en las costas de Sinaloa a Jalisco; 2) mientras que las proliferaciones de Cochlodinium polykrikoides durante los periodos verano-otoño son favorecidas por el efecto de otras proliferaciones algales previas sobre el ecosistema y por condiciones predominantemente locales en la bahía.

Phylogenetic analyses of Prorocentrum spp. and Alexandrium spp. isolated from northern coast of Vietnam based on 18S rDNA sequence.

Some species of marine dinoflagellates belonging to genera Alexandrium and Prorocentrum have been responsible for paralytic shellfish poisoning (PSP) and diarrheic shellfish poisoning (DSP), respectively Morphological and molecular studies of 4 species including Alexandrium sp. 5, Alexandrium sp. 16, Prorocentrum sp. 1 and Prorocentrum sp. 3 that were collected in Northern coast of Vietnam were presented for the first time. By morphologic observations, we identifiedAlexandrium sp. 5 and Alexandrium sp. 16 as Alexandrium minutum, Alexandrium affine, respectively; Prorocentrum sp. 1 and Prorocentrum sp. 3 as Prorocentrum mexicanum. Sequence data from the partial 18S riboxomal RNA genes have been used to generate a phylogenetic framework with database of GenBank. The obtained results of phylogenetic analyses of species of Prorocentrum spp. and Alexandrium spp. based on 18S rDNA sequences are similar to morphological observations. Thus, molecular tool would be helpful for the identification of dinoflagellate species and further taxonomic studies in Vietnam.

Synonymy and biogeography of the dinoflagellate genus Histioneis (Dinophysiales: Dinophyceae)

The genus Histioneis (=Parahistioneis) contains an excessive number of poorly described species, often based on the observation of a single specimen and ignoring the intraspecific variability. In order to investigate the validity of the species and to suggest synonyms, the original illustrations of all known species of Histioneis are reproduced and grouped based on the morphological similarity. The scarce records and the uncertainties on the identification at the species level are responsible of the lack of biogeographical information. Large and highly ornamented species tended to appear in tropical waters, whereas smaller and less ornamented species showed a wider distribution and they can also found in temperate waters such as the Mediterranean Sea. Rev. Biol. Trop. 55 (2): 459-477. Epub 2007 June, 29.

El género Histioneis (=Parahistioneis) tiene una cantidad excesiva de especies, descritas insuficientemente y a menudo a partir de un solo espécimen, ignorando la variabilidad intra-específica. Con el objetivo de investigar la validez de las especies y sugerir sinónimos, aquí se presentan las ilustraciones originales de Histioneis agrupadas según su parecido morfológico. Las escasas observaciones de Histioneis y las dudas en la identificación a nivel de especie son responsables de la falta de información sobre su distribución geográfica. Las especies de mayor tamaño y más ornamentadas son típicas de aguas tropicales. Las especies más pequeñas y menos ornamentadas presentan una distribución más amplia y pueden encontrarse también en aguas templadas, como el Mar Mediterráneo.

Epiphytic dinoflagellates associated with ciguatera in the northwestern coast of Cuba

The spatial and temporal abundance of epiphytic dinoflagellates associated with ciguatera was studied over two annual cycles (March 1999 to March 2000 and March 2001 to March 2002) in the northwestern coast of Cuba. From 14 species of macroalgae (Phaeophyta, Chlorophyta, and Rhodophyta), 1340 samples were obtained identifying seven species as potentially noxious; five of them are new reports for Cuba's phytobenthos: Prorocentrum belizeanum Faust, P. concavum Fukuyo, P. mexicanum Tafall, Coolia monotis Meunier, and Ostreopsis lenticularis Fukuyo. ANOVA/MANOVA analysis showed significant spatial differences: lower cell abundance near the shoreline adjacent to a river inlet and higher cell abundance in the deepest area. Prorocentrum lima (Ehrenberg) Dodge 1975 was found mainly on Phaeophyta followed by Chlorophyta and Rhodophyta. Gambierdiscus toxicus was found mainly on Phaeophyta followed by Rhodophyta and Chlorophyta. All the species reported in the study area were mainly on Padina spp. (Phaeophyta). Acanthophora spicifera (Rhodophyta) did not host dinoflagellate species. Environmental conditions in summer (higher temperature, more nutrients, greater water transparency, and low wind intensity) are suitable for macroalgae development, which serves as a substrate for potentially harmful dinoflagellates, and possibly the main vector for spreading ciguatera along the coast of Cuba.

Se estudió la abundancia espacial y temporal de dinoflagelados epífitos asociados a la ciguatera durante dos ciclos anuales (marzo 1999 a marzo 2000, y marzo 2001 a marzo 2002) en la costa del noroeste de Cuba. Recolectamos 14 especies de macroalgas (Phaeophyta, Chlorophyta y Rhodophyta) y obtuvimos 1340 muestras. Identificamos siete especies de dinoflagelados potencialmente nocivas, cinco de ellas nuevos registros para el fitobentos cubano: Prorocentrum belizeanum Faust, P. concavum Fukuyo, P. mexicanum Tafall, Coolia monotis Meunier, y Ostreopsis lenticulares Fukuyo. El análisis de ANOVA/MANOVA mostró diferencias espaciales significativas: la abundancia celular más baja se encontró cerca de la desembocadura del río y la más alta en el área más profunda. Prorocentrum lima (Ehrenberg) Dodge, se encontró principalmente sobre las Phaeophyta seguido de las Chlorophyta y Rhodophyta. Gambierdiscus toxicus se encontró principalmente sobre las Phaeophyta seguido de las Rhodophyta y Chlorophyta. Todas las especies halladas en el área del estudio estaban sobre Padina spp. (Phaeophyta). No se encontró ninguna especie de dinoflagelado sobre Acanthophora spicifera (Rhodophyta). Las condiciones ambientales en verano (temperatura, nutrientes, transparencia de agua y la baja velocidad del viento) favorecen el desarrollo de las macroalgas, siendo un substrato adecuado para el desarrollo de dinoflagelados potencialmente nocivos, y posiblemente el vector principal para la extensión de la ciguatera en la costa noroeste cubana.

Presencia de Cochlodinium catenatum (Gymnodiniales: Gymnodiniaceae) en mareas rojas de Bahía de Banderas, Pacífico mexicano / Presence of Cochlodinium catenatum (Gymnodiniales: Gymnodiniaceae) in red tides of Bahia de Banderas, Mexican Pacific

Se describe la evolución de una proliferación algal ictiotóxica (julio a diciembre del 2000) causada por el dinoflagelado Cochlodinium catenatum. La multiplicación anormal de este dinoflagelado se presentó a manera de decoloraciones dispersas dentro de un intervalo de temperatura de 25-32 º C y salinidades de 33-35 ups. La densidad de C. catenatum fue desde no detectable hasta 10 841 éls ml-1 . El evento se presentó en grandes extensiones en la Bahía de Banderas, afectando a 13 especies de peces, cuya muerte masiva se debió a sofocación por la obstrucción en las agallas y por excesiva producción de mucus. La población humana aledaña no presentó afecciones respiratorias ni irritaciones en la piel. Las dimensiones de C. catenatum sugieren que pueda presentar una reproducción hologámica y heterotálica. Por sus características morfológicas se sugiere que C. polykrikoides, C. heterolobatum y C. catenatum son una única especie. Esta última parece de reciente introducción en el Pacífico mexicano

The evolution of an ichthiotoxic algal bloom caused by the dinoflagellate Cochlodinium catenatum was studied from July to December 2000. The abnormal multiplication of this dinoflagellate occurred in the form of a discoloration spreading between a temperature and salinity interval of 25-32°C and 33-35 ups, respectively. The density of C. catenatum reached 10 841 cells ml-1 . The event was observed in large areas of Banderas Bay affecting 13 fish species, whose massive killing was due to suffocation (gill obstruction and excessive mucus production). The human population around the area did not present respiratory affections or skin irritation. The C. catenatum measurements suggest a hologamic and heterothalic reproduction. Their morphological characteristics suggest that C. polykrikoides, C. heterolobatum and C. catenatum are the same species. It is estimated that the species could be a recent introduction in the Mexican Pacific

Proliferaciones de Pseudo-nitzschia spp. (Bacillariophyceae) y otras especies del microplancton en la Bahía de Mazatlán, México / Blooms of Pseudo-nitzschia spp. (Bacillariophyceae) and other phytoplankton species at Bahia de Mazatlan, Mexico

Observaciones previas sobre el microplancton de la Bahía de Mazatlán, en el otoño de 1996, revelaron la existencia de altas densidades de Pseudo-nitzschia spp. Este mismo fenómeno se encontró en noviembre 1998 y un mes después se había desplazado al sur de la Bahía de Mazatlán, mientras que por esas mismas fechas, en California, EUA, se registraban accidentes de envenenamiento de mamíferos marinos, accidentes que en el noroeste de México se aprecian entre enero y marzo. Mensualmente se recolectaron muestras de agua superficial (< 0.5 m) y subsuperficial (10 m), de noviembre 1998 a enero 1999 y cada semana, entre febrero 1999 y mayo 2000; las muestras fueron analizadas por la técnica de Utermöhl a 400X. La cuantificación del microplancton presentó un amplio pulso invernal y otro menor en verano de cada ciclo anual. Con el empleo de microscopio electrónico (MEB y MET), se reconocieron cuatro especies de Pseudo-nitzschia y una más en estudio reciente. Las densidades de Pseudo-nitzschia fueron, en orden de importancia: 760 céls ml-1 (7 dic.1999), 610 (6 dic.1998), 335 (12 jul.1999), 198 (1º. feb. 1999), 170 (6 nov.1998), 123 (17 mar.1999), 108 (11 ago.1999). Otras especies de diatomeas (Thalassiosira spp., Asterionellopsis glacialis, Chaetoceros spp., Skeletonema costatum), dinoflagelados (Prorocentrum spp., Scripsiella trochoideda) y ciliados (Myrionecta rubra), manifestaron proliferaciones altas durante el período de este estudio

Observations on microplankton in the autumn of 1996 revealed the existence of high densities of Pseudo-nitzschia spp. A similar phenomenon was found in November 1998 and November 1999 and a month later it shifted to the southern Mazatlán Bay while in California, USA, incidents of the poisoning of sea mammals were being recorded; this also happened on the Mexican Pacific coasts from January to March. Water samples collected at surface (<0.5 m deep) and subsurface (10 m deep) monthly, from November 1998 to January 1999 and every week from February 1999 to May 2000, were analyzed by the Utermöhl technique at 400 enlargements. Phytoplankton quantification showed winter and summer pulses; the 1998-1999 period was higher than the 1999-2000 period. Five species of Pseudo-nitzschia were identified by electron microscopy (TEM and SEM); a new study has revealed other species. High values of Pseudo-nitzschia were observed: 730 P-n/ml (Dec. 1999), 610 P-n/ml (Dec. 1998), 335 P-n/ml (Jul. 1999), 198 P-n/ml (Feb. 1999), 170 P-n/ml (Nov. 1998), 123 P-n/ml (Mar. 1999), 108 P-n/ml (Aug. 1999). The blooms of other species of diatoms (Thalassiosira spp., Asterionellopsis glacialis, Chaetoceros spp., Skeletonema costatum), dinoflagellates (Prorocentrum spp., Scripsiella trochoidea) and ciliates (Myrionecta rubra) were also observed

Especies de dinoflagelados del género Gambierdiscus (Dinophyceae) del Mar Caribe mexicano / Species of dinoflagellates of the genus Gambierdiscus (Dinophyceae) in the Mexican Caribbean Sea

Algunos dinoflagelados de hábitos bénticos están relacionados con la ciguatera, por consumo de pescado, en áreas tropicales. En el Caribe mexicano la ciguatera es un padecimiento relativamente común, sin embargo solo existe un trabajo sobre este tema y muy pocos antecedentes publicados sobre fitoplancton y microalgas bénticas. En este estudio se analizó material recolectado en varios puntos a lo largo de las costas del Estado de Quintana Roo, tanto con red de fitoplancton (54 mm), como de sedimento y epífitas de plantas macroscópicas, para estudiar los dinoflagelados tóxicos y asociados. Se registra la presencia de tres especies del género Gambierdiscus, asociadas con la producción de toxinas causantes de la ciguatera: G. belizeanus, G. toxicus y G. yasumotoi, todas distribuídas en áreas costeras poco profundas, incluyendo lagunas costeras. Las especies han sido estudiadas con microscopía de luz y electrónica de barrido. Para el reconocimiento de las especies se emplearon los caracteres morfológicos usuales, pero eventualmente se pueden usar caracteres fisiológicos, ecológicos y moleculares. La llamada "comunidad ciguatoxigénica" también está formada por especies de los géneros Prorocentrum, Ostreopsis y Coolia, cuyo estudio florístico y taxonómico se recomienda ampliamente, así como investigaciones complementarias de aspectos biológicos, ecológicos, fisiológicos y epidemiológicos de esta comunidad

Some dinoflagellates with benthic habits are related to ciguatera intoxication by fish consumption, especially in tropical areas. In the Mexican Caribbean, ciguatera is relatively common, but only one paper seems to have been published on the subject, and there are very few publicactions on phytoplankton and benthic microalgae. Material collected along the coast of the State of Quintana Roo with phytoplankton net (54 mm) and directly from sediment and epiphytes of macroscopic plants, was searched for toxic and other associated dinoflagellates. Samples were studied by light and scanning electron microscopy. Morphological characters were useful for species identification, but eventually physiological, ecological and molecular characters could also be used. Three species of Gambierdiscus, related to the production of ciguatera toxins, were identified: G. belizeanus, G. toxicus and G. yasumotoi. They are distributed in shallow coastal areas, including coastal lagoons

Paralytic Shellfish Poisoning (PSP) in Margarita Island, Venezuela

A severe outbreak of Paralytic Shellfish Poisoning (PSP) occurred in Manzanillo and Guayacán, northwestern coast of Margarita Island, Venezuela, between August and October 1991. A bloom of dinoflagellates including Prorocentrum gracile, Gymnodinium catenatum and Alexandrium tamarense seemed to be responsible for this outbreak. Levels of PSP toxins in mussels (Perna perna) exceeded the international safety limit of saxitoxin, 80 µg STX/100 g meat. PSP toxin values varied between 2 548 and 115 µg STX/100 g meat in Manzanillo, and between 1 422 and 86 µg STX/100 g meat in Guayacán. At both locations, the highest levels were detected in August, when 24 patients exhibited typical symptoms of PSP toxicity after consuming cooked mussels (16 required hospitalization). A high pressure liquid chromatographic (HPLC) procedure was recently used on the 1991 samples. The major toxin detected in samples of both locations was decarbamoyl saxitoxin (dcSTX), but low concentrations of saxitoxin were also found in Manzanillo samples. Gonyautoxins GTX1, GTX2 and GTX3 were detected only at Guayacán, while in both locations, decarbamoylgonyatouxin (dcGTX2,3) toxins were detected. These findings represent the first time that causative toxins of PSP in Venezuela have been chemically identified, and confirm the presence of dcSTX and dcGTX in mussels from the Caribbean Sea. The presence of dcSTX and dcGTX in shellfish is indicative that Gymnodinium catenatum was a causative organism for outbreak of PSP

Un severo brote de intoxicación paralizante por moluscos (PSP en inglés) ocurrió en Manzanillo y Guayacán en la costa noroeste de la Isla de Margarita, Venezuela entre agosto y octubre de 1991. Una proliferación de Prorocentrum gracile, Gymnodinium catenatum y Alexandrium tamarense causó el brote. Los niveles de PSP en mejillón (Perna perna) superaron los niveles máximos permisibles de saxitoxina, 80 µg STX/100g carne. Los niveles de toxinas variaron entre 2 548 y 115 µg STX/100 g carne en Manzanillo y entre 1 422 y 86 µg STX/100g carne en Guayacán. En ambas localidades, los máximos niveles se detectaron en agosto, cuando 24 personas presentaron síntomas típicos de PSP después de consumir mejillones cocidos (16 fueron hospitalizados). Se aplicó recientemente cromatografía líquida de alta presión (HPLC) a muestras del año 1991 y la toxina más detectada fue decarbamoyl saxitoxina (dcSTX), pero también se encontró saxitoxinas en muestras de Manzanillo. Las gonyautoxinas GTX1, GTX2 y GTX3 solo se encontraron en Guayacán; en ambas localidades se detectó decarbamoylgonyatouxin (dcGTX2,3). Estos hallazgos representan la primera vez que las toxinas causantes de un brote de PSP en Venezuela han sido químicamente identificadas, confirmando la presencia de dcSTX y dcGTX en mejillones del mar Caribe. La presencia de dcSTX y dcGTX en moluscos, indica que G. catenatum fue el organismo responsable de la intoxicación

Presencia de los dinoflagelados Ceratium dens, C. fusus y C. furca (Gonyaulacales: Ceratiaceae) en el Golfo de Nicoya, Costa Rica / Presence of the dinoflagellates Ceratium dens, C. fusus and C. furca (Gonyaulacales: Ceratiaceae) in Golfo de Nicoya, Costa Rica

Las proliferaciones algales nocivas (PAN) son un fenómeno frecuente en el Golfo de Nicoya. La morfología y fisiología de estas microalgas son muy importantes debido al hecho de que las especies involucradas en estos eventos presentan características adaptativas. PAN producidas por dinoflagelados del género Ceratium son comunes en algunas partes del mundo, sin embargo, a pesar del hecho de que la producción de altas concentraciones de toxinas paralíticas sólo se ha documentado a nivel experimental, éste género ha sido asociado con la mortalidad de organismos acuáticos y con la disminución en la calidad del agua, así como el responsable de la mortalidad de ostras y larvas de gambas. Algunas especies del género Ceratium han sido asociados con eventos de mortalidad en peces. Durante un reciente fenómeno PAN que ocurrió cerca de la Isla Tortuga en el Golfo de Nicoya, los pescadores en el área informaron muertes masivas de peces enjaulados. Se tomaron muestras de una PAN que producía una discoloración anaranjada en el agua y tenía un olor fétido. Estas muestras fueron procesadas para observar el detalle ultraestructural usando el microscopio electrónico. En muestras tomadas en superficie, los dinoflagelados observados fueron Ceratium furca, C. fusus y C. dens. El conteo celular reveló cuatro millones de células de este género por litro. Los cambios morfológicos de estas especies son muy variables; por consiguiente la microscopía electrónica es una herramienta muy útil en el estudio ultraestructural de estos organismos. Esta es la primera vez que tres especies del género Ceratium se conocen como productoras concurrentes de PAN en Costa Rica

Harmful Algae Blooms (HAB) are a frequent phenomenon in the Gulf of Nicoya, Costa Rica, as in other parts of the world. The morphology and physiology of these microalgae are important because HAB species have adaptive characteristics. The production of high concentrations of paralytic toxins by Ceratium dinoflagellates has only been documented at the experimental level. However, this genus has been associated with the mortality of aquatic organisms, including oyster and shrimp larva, and fish, and with decreased water quality. Recently, fishermen reported massive mortality of encaged fish near Tortuga Island (Gulf of Nicoya). Samples were taken from an algal bloom that had produced an orange coloration and had a strong foul-smelling odor. Ultrastructural details were examined with scanning electron microscopy. The dinoflagellates Ceratium dens, C. furca and C. fusus were found in samples taken at the surface. The cell count revealed four million cells of this genus per liter. The morphological variability of these species is high; therefore electron microscopy is an useful tool in the ultrastructural study of these organisms. This is the first time that three Ceratium species are reported concurrently producing harmful blooms in Costa Rica

Morphological variation of dinoflagellate Prorocentrum lima (Ehrenberg) Dodge with geographical difference.

Prorocentrum lima (Ehrenberg) Dodge, one of the cosmopolitan dinoflagellates, is basically benthic and is found on the surface of macroalgae and detritus. The identification of this species requires detailed morphological observation because of its close similarity to other benthic Prorocentrum species. The purpose of this study is to detect the morphological variability of P. lima using culture clones collected from several areas to find an adequate way of subdividing the species. In this study, 33 clones of P. lima were collected from Saipan, Tahiti, Indonesia, Japan and Bermuda, and their thecal valves and periflagellar area were observed by means of light microscopy with differential interference contrast optics and scanning electron microscopy. In general cells have two centrally located pyrenoids and a posterior nucleus. The surface of both valves has many valve pores except the center. Evenly spaced marginal pores are located along the edge of the valves. P. lima samples studied herein were subdivided into four major types (ellipsoidal, general, short, and elongate ovoid) according to their shapes, length-to-width ratio and number of valve pores. The length-to-width ratios of ellipsoidal, general, short, and elongate ovoid types were 1.32, 1.33-1.43, 1.20-1.27, and 1.53-1.60 microm respectively. Also there were slight differences in the number of valve pores. The number of valve pores examined in this study ranges from 40 to 97: ellipsoidal, general, and short ovoid types range from 40 to 91, while an elongate ovoid type ranges from 80 to 97. The combination of valve shape, number of valve pores and length-to-width ratio provides useful information on the morphological variation of P. lima.

Limnology of Botos Lake, a tropical crater lake in Costa Rica

Botos Lake, located at the Poas Volcano complex (Costa Rica) was sampled eight times from 1994 to 1996 for physicochemical conditions of the water column and phytoplanktonic community composition. Depth was measured at fixed intervals in several transects across the lake to determine its main morphometric characteristics. The lake has an outlet to the north. It is located 2580 m above sea level and is shallow, with a mean depth of 1.8 m and a relative depth of 2.42 (surface area 10.33 ha, estimated volume 47.3 hm3). The lake showed an isothermal water column in all occasions, but it heats and cools completely according to weather fluctuations. Water transparency reached the bottom on most occasions (> 9 m). The results support the idea that the lake is polymictic and oligotrophic. The lake has at least 23 species of planktonic algae, but it was always dominated by dinoflagellates, especially Peridinium inconspicuum. The shore line is populated by a sparse population of Isoetes sp. and Eleocharis sp. mainly in the northern shore where the bottom has a gentle slope and the forest does not reach the shore.