Diversity and Toxicity of the Genus Coolia Meunier in Brazil, and Detection of 44-Methyl Gambierone in Coolia tropicalis.

Coolia is a genus of marine benthic dinoflagellates which is widely distributed in tropical and temperate zones. Toxicity has been reported in selected Coolia species, although the identity of causative compounds is still controversial. In this study, we investigated the taxonomical and toxicological aspects of Coolia species from Brazil. Since light- and electron microscopy-based morphology was not enough to distinguish small-celled species, ITS and LSU D1-D3 phylogenetic analyses were used for species definition. Cultures of Coolia palmyrensis and Coolia santacroce were established from samples collected along the northeastern Brazilian coast, the first record of both species in South Atlantic waters. Cultures of Coolia malayensis and Coolia tropicalis were also established and exhibited acute in vivo toxicity to adults of Artemia salina, while C. palmyrensis and C. santacroce were non-toxic. The presence of 30 yessotoxin analogues, 7 metabolites of Coolia and 44 Gambierdiscus metabolites was screened in 14 strains of Coolia. 44-methyl gambierone (formerly referred to as MTX3) and a new isomer of this compound were detected only in C. tropicalis, using both low- and high-resolution LC-MS/MS. To our knowledge, this is the first report of gambierone analogues in dinoflagellates other than Gambierdiscus; the role of C. tropicalis in ciguatera poisoning thus deserves to be considered in further investigations.

Occurrence of Ostreopsis lenticularis (Dinophyceae: Gonyaulacales) from the Archipiélago de Revillagigedo, Mexican Pacific.

From December 2016 to May 2017, 22 phytoplankton surface samples were collected with a 20-µm mesh net at three islands of the Archipiélago de Revillagigedo (Partida, Socorro and San Benedicto), Mexican Pacific. The sites depth was approximately 20-80 m; the surface water temperature was 21-27 °C. The potentially toxic benthic dinoflagellate Ostreopsis lenticularis was present in all the samples. Cells had a lenticular to broadly oval shape, 65-100 µm long and 50-80 µm wide. The taxonomy of the genus Ostreopsis has been unclear due to equivocal ascribing some taxonomic features among species. The identification of specimens from the archipelago was made based on the most important taxonomic characteristics: the thecal plates, the presence of two types of thecal pores (larger and smaller), and the lack of cingulum undulation. The studied cells are compared with O. cf. siamensis, O. labens and O. marina. This is the first record of the species in the archipelago waters.

Ceratocorys mariaovidiorum sp. nov. (Gonyaulacales), a new dinoflagellate species previously reported as Protoceratium reticulatum.

The family Ceratocoryaceae includes the genera Ceratocorys, Protoceratium, and Schuettiella, whose phylogenetic relationships are poorly known. Here, the new non-yessotoxin-producing species of the genus Ceratocorys, Ceratocorys mariaovidiorum sp. nov., previously reported as the toxic Protoceratium reticulatum, is described from examinations by light and scanning electron microscopy, molecular phylogeny, and toxin analyses. The species description is made from culture samples of strains CCMP1740 and CCMP404 from USA waters. Ceratocorys mariaovidiorum is globular and has thick and strongly reticulated plates with one pore within each reticule, just like P. reticulatum, but the key difference between the two species is the presence of five precingular plates in C. mariaovidiorum instead of six as in P. reticulatum. The thecal plate formula is Po, 4', 0a, 5″, 6c, ~7s, 5‴, 0p, 2''''. The apical pore plate is oval with a λ-shaped pore. The first apical plate is narrow with a ventral pore on the right anterior side; it contacts the apical pore plate and its contact with the anterior sulcal plate is slight or absent. The fourth precingular plate of other Gonyaulacales is absent. Ceratocorys mariaovidiorum may have small spines on the second antapical plate. A phylogenetic study based on internal transcribed spacer/5.8SrDNA supports the morphological classification of C. mariaovidiorum as a new species of Ceratocorys and in a different clade from P. reticulatum.

Benthic flattened cells of the phylogenetically related marine dinoflagellates Protoceratium reticulatum and Ceratocorys mariaovidiorum (Gonyaulacales): a new type of cyst?

A planktonic-benthic relationship has been described for many dinoflagellate species as part of their ecological strategy to overcome highly variable aquatic environments. Here, the phylogenetically and morphologically related marine dinoflagellates Protoceratium reticulatum and Ceratocorys mariaovidiorum were studied in relation to an unknown benthic life form. In vivo and fixed samples from cultures were analyzed in detail by light and scanning electron microscopy. In both species, a cell type with a morphology different from that of vegetative cells was observed in cultures grown until stationary phase. This cell type was always benthic, swimming sporadically only when it was disturbed. Its main feature included a strong dorsoventral compression. These cells originated from vegetative cells whose protoplasm underwent a progressive flattening, resulting in a gradual detachment of the reticulate and thick thecal plates and the formation of very thin non-reticulated new plates with pores. When returned to fresh full-strength medium, the cells recovered their spherical vegetative-like morphology, including new reticulated thick plates and subsequent cell divisions. The kinetics of flattened cell formation showed that in both species, this cell type increased exponentially until the onset of the culture stationary phase and then decreased. The results of this study are discussed in the context of the planktonic-benthic coupling in dinoflagellate life cycles, including those newly appreciated to be well adapted to the benthic environment.

Ultrastructure and Phylogeny of Kirithra asteri gen. et sp. nov. (Ceratoperidiniaceae, Dinophyceae) - a Free-Living, Thin-Walled Marine Photosynthetic Dinoflagellate from Argentina.

A gymnodinioid photosynthetic dinoflagellate was isolated from Argentina and examined by light and electron microscopy and analysis of nuclear-encoded LSU rDNA. Kirithra asteri gen. et sp. nov. was proposed as morphology and molecular phylogeny separated this dinoflagellate from others within the family Ceratoperidiniaceae. Cells were surrounded by a hyaline amphiesma comprising polygonal vesicles. Each vesicle contained a honeycomb and a trilaminar structure. An anterior sulcal extension ending in a complete circle formed the apical structure complex (ASC), which characterizes Ceratoperidiniaceae. The ASC comprised three rows of vesicles. The nucleus was located in the hypocone, and several large, irregularly shaped vesicles were present in the epi- and hypocone. Chloroplasts were surrounded by three membranes, and grana-like arrangements of thylakoids were observed in one strain used for ultrastructural study. The cell centre contained 1-3 multiple-stalked pyrenoids and membrane-bound vesicles containing tile-like structures surrounded each pyrenoid. Two pusules with collecting chambers and associated vesicles branched off each of the flagellar canals. The flagellar apparatus featured a ventral connective between the amphiesma and the R1 root, and almost opposite basal bodies, rarely seen in dinoflagellates. This was the first ultrastructural study of a species within Ceratoperidiniaceae.

The Synonymy of the Toxic Dinoflagellates Prorocentrum mexicanum and P. rhathymum and the Description of P. steidingerae sp. nov. (Prorocentrales, Dinophyceae).

Prorocentrum mexicanum and P. rhathymum are toxicologically important dinoflagellates, but their relationship is not well defined. We investigated strains from Puerto Rico and Brazil by light and scanning electron microscopies. We provide molecular data from a strain isolated near the type locality of P. rhathymum, and the first morphological and molecular data from the South Atlantic Ocean. The rRNA gene (rDNA) sequences of the Puerto Rican and Brazilian strains were identical, and their morphologies fit the description of P. rhathymum. In the molecular phylogenies, the globally distributed populations under the names P. mexicanum and P. rhathymum are intermixed and branched together, except for several divergent strains from Florida and Cuba. We examined the original descriptions and iconotypes of the species Prorocentrum maximum, P. brochii, P. mexicanum, and P. rhathymum. We conclude that P. maximum sensu Schiller's figure 41a corresponds to the earlier description of this species; the split of P. mexicanum and P. rhathymum was based on a misidentification because P. mexicanum sensu Cortés-Altamirano & Sierra-Beltrán corresponds to P. texanum var. cuspidatum; and P. rhathymum is a junior synonym of P. mexicanum. Several Floridian and Cuban strains correspond to a new species, which we describe as Prorocentrum steidingerae sp. nov.

Circadian rhythm of a red-tide dinoflagellate Peridinium quadridentatum in the port of Veracruz, Gulf of Mexico, its thecal morphology, nomenclature and geographical distribution.

A circadian rhythm of the dinoflagellate Peridinium quadridentatum was studied at a time-series station in the southwestern Gulf of Mexico, in May 2007. Different substrates (water column, the seagrass Thalassia testudinum, macroalgae, coral rubble and sandy sediment surface) were sampled at the site at 1.5-3.5m depth. In the samples of coral rubble, P. quadridentatum was scarce. In the water column, the species showed an abundance peak at 15:00. The cell abundance of P. quadridentatum in Thalassia samples increased from 15:00 until 18:00 (1.81×10(4)cells/gsubstratewet weight), and then continuously decreased until 06:00. Changes in P. quadridentatum cell abundance on macroalgae followed the same trend as on Thalassia, with the maximal value at 18:00. The higher abundance of P. quadridentatum (up to 1.40×10(4)cells/gSWW) in macroalgae samples showed the preference for seaweeds. P. quadridentatum has a neritic tropical-boreal distribution. A new combination is proposed: Peridinium quadridentatum var. trispiniferum.

Gonyaulax taylorii, a new yessotoxins-producer dinoflagellate species from Chilean waters.

In summer 2009, during a survey in Bahía Mejillones, a dense bloom of a dinoflagellate from the genus Gonyaulax was detected, as well as the presence of yessotoxin. Phytoplankton samples were analyzed in detail by light and scanning electron microscopy (SEM), revealing the presence of Gonyaulax taylorii. Morphological examination showed that the cells in the bloom fit in Gonyaulax jollifei Murray et Whitting sensu Dodge, subsequently classified as Gonyaulax taylorii by Carbonell-Moore. In this context, some inconsistencies have been found in regard to the holotype; the plate 1"' appears as two plates, 1‴ and 2‴, showing a suture that does not exist in Dodge's figure of G. jollifei, from where the holotype was drawn, nor within the samples collected. Therefore, this plate has been originally described erroneously as two plates named 1"' and 2"' instead of only one named 1‴. After this correction, this species has five instead of six postcingular plates. For this reason, the description of this species must be emended. Phytoplankton net samples were found to contain yessotoxin and homoyessotoxin, with concentrations below 1pgcell-1. The present study identifies, therefore, the dinoflagellate G. taylorii as a new source of yessotoxins.

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

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

Morphological observations of the marine planktonic dinoflagellate Phalacroma turbineum Kofoid et Michener (Dinophyta), with discussion on its taxonomy and distribution.

The marine planktonic thecate dinoflagellate Phalacroma turbineum Kofoid et Michener was found at two oceanic stations in the southern Gulf of Mexico and studied by light and scanning electron microscopy. This species is extremely rare and has not been reported since 1911. The terms reticules and septa are introduced here for structures of theca and cingulum of the species. The peculiar morphological characters of P. turbineum are described: (1) two separate pores that might represent flagellar pores, (2) right and left sulcal lists are united, (3) left sulcal list showed no apparent ribs, (4) a parasagittal list occurs in the hypotheca as continuation of the left sulcal list, (5) structural complexity of the cingulum, with septa along the cingulum, (6) strong ribs supporting the two cingular lists, (7) large and spaced reticules in the theca, with elevated ridges, and (8) an elongation of the hypotheca. No chloroplasts were detected. The morphology and taxonomy of P. turbineum are discussed, especially the possibility that the species may be considered as belonging to a new genus. Finally, although information is yet limited, we suggest that the species is distributed in equatorial and tropical zones of both the Atlantic and Pacific Oceans, in oceanic environments.

[Dinoflagellates (Dinophyta) of orders Dinophysiales and Prorocentrales of the Veracruz Reef System, Mexico]. / Dinoflagelados (Dinophyta) de los ordenes Prorocentrales y Dinophysiales del Sistema Arrecifal Veracruzano, México.

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 30 microm 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.

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.

Identification and characterization of potentially algal-lytic marine bacteria strongly associated with the toxic dinoflagellate Alexandrium catenella.

The toxic dinoflagellate Alexandrium catenella isolated from fjords in Southern Chile produces several analogues of saxitoxin and has been associated with outbreaks of paralytic shellfish poisoning. Three bacterial strains, which remained in close association with this dinoflagellate in culture, were isolated by inoculating the dinoflagellate onto marine agar. The phenotypically different cultivable bacterial colonies were purified. Their genetic identification was done by polymerase chain reaction amplification of the 16S rRNA genes. Partial sequence analysis suggested that the most probable affiliations were to two bacterial phyla: Proteobacteria and the Cytophaga group. The molecular identification was complemented by morphological data and biochemical profiling. The three bacterial species, when grown separately from phytoplankton cells in high-nutrient media, released algal-lytic compounds together with aminopeptidase, lipase, glucosaminidase, and alkaline phosphatase. When the same bacteria, free of organic nutrients, were added back to the algal culture they displayed no detrimental effects on the dinoflagellate cells and recovered their symbiotic characteristics. This observation is consistent with phylogenetic analysis that reveals that these bacteria correspond to species distinct from other bacterial strains previously classified as algicidal bacteria. Thus, bacterial-derived lytic activities are expressed only in the presence of high-nutrient culture media and it is likely that in situ environmental conditions may modulate their expression.

La marea roja causada por el dinoflagelado Alexandrium tamarense en la costa Pacífica colombiana (2001) / The red tide caused by the dinoflagellate Alexandrium tamarense in the Colombian Pacific coast (2001)

El 26 de marzo de 2001 se registró por primera vez en las aguas del Pacífico colombiano, en el área de la Ensenada de Tumaco, la aparición de una marea roja producida por la especie Alexandrium tamarense con valores que superaron las 7.5 x 106 céls l-1 , la marea se mantuvo hacia la región oceánica, derivando en sentido sur-norte por efecto de las corrientes, hasta ser vista por ultima vez cerca a la Isla Gorgona, casi tres semanas después. Un año mas tarde, en marzo de 2002, una segunda proliferación, conformada por la misma especie, se reportó cerca de Cabo Corrientes con una concentración de 1.6 x 106 céls l -1 . Ambos casos estuvieron relacionados con la presencia de bajas temperaturas en la superficie del mar y no estuvieron asociadas con fenómenos de intoxicación y mortalidad

From April 26th to May 15th 2001, a large algae bloom was observed off Tumaco Bay on the Pacific coast of Colombia. This was the first harmful algae bloom (HAB) reported in the region, and reached Gorgona Island, about 120 km north. Ayear later, starting March 2002, an offshore HAB developed from Cabo Corrientes North to Solano Bay. The typical abundance during the blooms reached 7.5 x 106 cells l-1 for the 2001 event and 1.6 x 106 cells l-1 for the 2002 event. During both events, low temperature and high salinity were recorded. Typical measurements in the area are 27-27.5°C and 30-31.5 psu. Values observed during the two events were 24-24.6°C and 33-34 psu; 3°C below normal and more than 2.5 psu above average values. These conditions are indicative of local upwelling processes at the time of the events. On both occasions, cells corresponding to the Alexandrium catenella/fundeyense/tamarense complex represented 99-100% of the biomass. It was difficult to differentiate the cells from A. catenella, but the presence of short chains of only 4 cells (single cells represented most of the biomass) was suggestive of A. tamarense. Shape, dimensions, and detailed structure of the apical pore complex, first apical plate, posterior sulcal plate, and position of the ventral pore on plate 1’ of cells were consistent with the description of A. tamarense, which has not been reported in the tropical East Pacific. The Control Center of Pacific Contamination of the Maritime General Direction of the Colombian Navy has been monitoring the area since 1994 without finding this species or HABs. This leads us to consider the two events as caused by recently introduced species, where local upwelling processes favor permanent and cyclic HABs. However, during these two events, there were no reports of effects on marine biota or of human poisoning, probably because the blooms occurred some distance offshore and far from exploited shellfish beds

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

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

Proliferaciones algales nocivas de cianobacterias (Oscillatoriaceae) y dinoflagelados (Gymnodiniaceae) en el Golfo de Nicoya, Costa Rica / Harmful blooms of cyanobacteria (Oscillatoriaceae) and dinoflagellates (Gymnodiniaceae) in the Golfo de Nicoya, Costa Rica

Recently, the Pacific coast of Costa Rica has experienced an increase in both magnitude and frequency of harmful algae blooms (HAB). The lack of data regarding the dynamics of these events in the area, and the species of microalgae that produce them, are themes of great interest. The blooms have produced negative impacts on fishery resources and on human health in Costa Rica. In May 2002 a HAB left a large number of dead fish along the central Pacific coast. Water samples were collected using a phytoplankton net and fixed for subsequent processing by electron microscopy. In addition, a one liter sample of surface water was taken for later cell count. In the observed HAB, the dominating organisms found were the cyanobacteria Trichodesmiun erythraeum surrounded by high concentrations of Gram - bacteria and the dinoflagellate Cochlodinium cf. polykrikoides. T. erythraeum, is one of the most important N 2 fixing cyanobacteria in marine waters that has been associated with HAB events in diverse parts of the world as well as with symptoms that produce contact dermatitis and other discomforts. C. cf. polykrikoides is a dinoflagellete associated with fish kills; although the type of associated toxins are unknown. In a national newspaper 17 cases of intoxication in humans were reported during this same period, which presented respiratory disorders and burning of the eyes. This is the first report in Costa Rica where a cyanobacteria and a dinoflagellate were observed together producing HAB

Recientemente, la costa del Pacífico de Costa Rica ha experimentado un aumento en magnitud y frecuencia de proliferaciones algales nocivas (PAN). La falta de datos con respecto a la dinámica de estos eventos en el área, y las especies de microalgas que los producen, son temas de mucho interés. Las PAN han producido impactos negativos en los recursos pesqueros y en la salud humana en Costa Rica. En mayo de 2002, una PAN se observó frente a las playas a lo largo del Pacífico central; además, se observó un gran número y diversidad de peces muertos. Las muestras de agua fueron recolectadas usando una red de fitoplancton y se fijaron para ser procesadas posteriormente con microscopía electrónica. Asimismo, se tomó un litro de muestra de la superficie para su posterior conteo celular. En la PAN observada, los organismos dominantes fueron la cianobacteria Trichodesmiun erythraeum, rodeada por altas concentraciones de bacterias Gram -, y el dinoflagelado Cochlodinium cf. polykrikoides. T. erythraeum, es una de las principales cianobacterias fijadoras de N2 atmosférico en aguas marinas, y se ha asociado con los eventos PAN en diversas partes del mundo, produciendo síntomas como dermatitis por contacto con la brisa marina y otras afecciones. C. cf. polykrikoides es un dinoflagelado asociado con mortalidad de peces; aunque el tipo de toxinas asociadas aún es desconocido. En un periódico nacional se reportaron 17 casos de intoxicación en humanos durante este mismo periodo de PAN, los afectados presentaron desórdenes respiratorios e irritación en los ojos. Éste es el primer informe en Costa Rica dónde se observaron cianobacterias y dinoflagelados juntos produciendo PAN. Este tipo de fenómenos debe analizarse y debe documentarse, para habilitar una comprensión en la dinámica y los factores asociados con el aumento de estos eventos en el Pacífico costarricense

[The red tide caused by the dinoflagellate Alexandrium tamarense in the Colombian Pacific coast (2001)]. / La marea roja causada por el dinoflagelado Alexandrium tamarense en la costa Pacífica Colombiana (2001).

From April 26th to May 15th 2001, a large algae bloom was observed off Tumaco Bay on the Pacific coast of Colombia. This was the first harmful algae bloom (HAB) reported in the region, and reached Gorgona Island, about 120 km north. A year later, starting March 2002, an offshore HAB developed from Cabo Corrientes North to Solano Bay. The typical abundance during the blooms reached 7.5 x 10(6) cells l(-1) for the 2001 event and 1.6 x 10(6) cells l(-1) for the 2002 event. During both events, low temperature and high salinity were recorded. Typical measurements in the area are 27-27.5 degrees C and 30-31.5 psu. Values observed during the two events were 24-24.6 degrees C and 33-34 psu; 3 degrees C below normal and more than 2.5 psu above average values. These conditions are indicative of local upwelling processes at the time of the events. On both occasions, cells corresponding to the Alexandrium catenella/fundeyense/tamarense complex represented 99-100% of the biomass. It was difficult to differentiate the cells from A. catenella, but the presence of short chains of only 4 cells (single cells represented most of the biomass) was suggestive of A. tamarense. Shape, dimensions, and detailed structure of the apical pore complex, first apical plate, posterior sulcal plate, and position of the ventral pore on plate 1' of cells were consistent with the description of A. tamarense, which has not been reported in the tropical East Pacific. The Control Center of Pacific Contamination of the Maritime General Direction of the Colombian Navy has been monitoring the area since 1994 without finding this species or HABs. This leads us to consider the two events as caused by recently introduced species, where local upwelling processes favor permanent and cyclic HABs. However, during these two events, there were no reports of effects on marine biota or of human poisoning, probably because the blooms occurred some distance offshore and far from exploited shellfish beds.

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

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.