First record and geographic range extension of the coccolithophore Scyphosphaera apsteinii Lohman, 1902 (Haptophyta: Pontosphaeraceae) from the Pacific coast of Mexico

The coccolithophorid Scyphosphaera apsteinii is here reported for the first time from waters off the west coast of the Baja California Peninsula. Scypho­sphaera apsteinii is the type species of the genus Scyphosphaera and had hitherto been recorded only in the Atlantic and Indian Oceans, the Gulf of Mexico, the Mediterranean, and the Caribbean Seas. Specimens were found in samples collected in nets off Isla de Guadalupe in January 2013. This recording thus extends the geographical distribution of S. apsteinii from the Central Pacific (Hawaii) to the Eastern Pacific (NW Mexico)

Ecological and Physiological Studies of Gymnodinium catenatum in the Mexican Pacific: A Review

This review presents a detailed analysis of the state of knowledge of studies done in Mexico related to the dinoflagellate Gymnodinium catenatum, a paralytic toxin producer. This species was first reported in the Gulf of California in 1939; since then most studies in Mexico have focused on local blooms and seasonal variations. G. catenatum is most abundant during March and April, usually associated with water temperatures between 18 and 25 ºC and an increase in nutrients. In vitro studies of G. catenatum strains from different bays along the Pacific coast of Mexico show that this species can grow in wide ranges of salinities, temperatures, and N:P ratios. Latitudinal differences are observed in the toxicity and toxin profile, but the presence of dcSTX, dcGTX2-3, C1, and C2 are usual components. A common characteristic of the toxin profile found in shellfish, when G. catenatum is present in the coastal environment, is the detection of dcGTX2-3, dcSTX, C1, and C2. Few bioassay studies have reported effects in mollusks and lethal effects in mice, and shrimp; however no adverse effects have been observed in the copepod Acartia clausi. Interestingly, genetic sequencing of D1-D2 LSU rDNA revealed that it differs only in one base pair, compared with strains from other regions

Variabilidad del estado trófico y la biomasa del fitoplancton de Bahía Concepción, Golfo de California (1997-1999)

To determine the effect of the phytoplankton biomass and the trophic status in Bahía Concepción in the centralwest part of the Gulf of California an hydro-biologic study was conducted from 1997 to 1999. Temperature, dissolved oxygen, inorganic nutrients (nitrate, nitrite, phosphate and silicate) and phytoplankton biomass (chlorophyll a) concentrations were measured. Hydrographic conditions shown a mixing period (October-April), two transition periods (April-May and September-October) and a stratification period (June-September). Warmest temperatures were observed during 1998 and coldest in 1997. Dissolved oxygen values shown an hypoxic layer (<2.7±0.78 ml l-1), during the stratified period below 20 m depth. During the transition period two peaks of phytoplankton biomass were observed, on spring and summer, which matched with those reported for coastal lagoons at similar latitudes, however the highest biomasses were observed in the stratification period, particularly below 15 m depth. The scale of nutrients showed an eutrophy for phosphate and silicate all the year. The trophic index revealed an oligotrophy state for phosphate, nitrate and nitrite had a dominant status with the exception for the transition periods, when the mesotrophic conditions were presents. These results suggest that phytoplankton biomass is associated with the natural inputs of nutrients and that trophic conditions (mesotrophy or eutrophy) were determined for the hydrographic of the area.Con el propósito de determinar la variación de la biomasa del fitoplancton (clorofila a) y el estado trófico de Bahía Concepción ubicada en la parte central oeste del Golfo de California, se realizó un estudio hidro-biológico durante el período de 1997 a 1999. Se determinó la temperatura, la concentración del oxígeno disuelto y de nutrientes inorgánicos (nitrato, nitrito, fosfato y silicato), y la biomasa fitoplanctónica (clorofila a). Las condiciones hidrográficas muestran un período de mezcla (octubre-abril), dos de transición (abril-mayo, septiembre-octubre) y uno de estratificación (junio-septiembre). Las temperaturas más cálidas durante el periodo de estudio fueron observadas durante 1998 y las más frías en 1997 para todos los períodos hidrográficos. Los valores de oxígeno disuelto muestran una zona de hipoxia durante el período estratificado (< 2.7±0.78 ml l-1), por abajo de los 20 metros de profundidad. Durante los períodos de transición se observó un incremento de la biomasa fitoplanctónica similar al que se observa como máximos de primavera y verano de algunas lagunas costeras en latitudes similares, sin embargo la mayor biomasa se detectó en el período de estratificación, particularmente por abajo de los 15 m. La escala de nutrientes mostró un estado de eutrofía para fosfato y silicato todo el año. El índice trófico reveló que la oligotrofía para fosfatos, nitratos y nitritos es el estado dominante, con excepción de los períodos de transición, que es cuando la mesotrofía se presentó. Los resultados sugieren que los incrementos fitoplanctónicos en Bahía Concepción se deben al suministro de nutrientes de origen natural y que las condiciones tróficas (mesotrofía o eutrofía), son determinadas por las condiciones hidrográficas del área

Co-ocurrencia de Chattonella marina y Gymnodinium catenatum en laBahía de LaPaz, Golfo de California (primavera2009)

During the period of 24 March to 14 May 2009, water and net samples were obtained for phytoplankton analyses; one aliquot was fixed in Lugol´s solution for species quantification and identification. Net samples were used for the identification of live phytoplankton species. Additionally, temperature in situ, chlorophyll a and inorganic nutrients were measured weekly in three stations. Two species were identified: Chattonella marina (Subrahmanyan) Y. Hara et Chihara and Gymnodinium catenatum Graham. Chattonella marina was the most abundant species with a density at subsurface level of 14 × 103 to 36 × 103 cell L-1 . Gymnodinium catenatum had densities were of 1 × 103 to 19 × 103 cell L-1 . Water column temperature was quasi homogeneous from surface to 20 m in depth, with an interval of 19.5 to 22.0 °C and 20.0 to 21.5 °C from March to April respectively. In the middle of May stratification of the water column initiated with a slight temperature difference of 5.0 °C recorded from surface to 20 m in depth. Nitrates varied from 0.5 to 11.0 µM and orthophosphates from 0.4 to 2.6 µM. Chlorophyll a showed a value at surface level of 7.5 mg m-3 and 3.5 mg m-3 at 20 m in March; in May chlorophyll a values ranged between 2.0 to 7.0 mg m-3 . We conclude that the presence of these two species during this study period was associated to the relaxation of the mixing processes in the zoneDurante el período del 24 de marzo al 14 de mayo de 2009 en la Bahía de La Paz, se obtuvieron muestras de agua y de red para análisis de fitoplancton. Una alícuota se fijó con una solución de Lugol para la identificación y cuantificación, la de red se utilizó para la identificación in vivo. Semanalmente se midió la temperatura in situ, se determinaron nutrientes inorgánicos y clorofila a en tres estaciones. Se identificaron dos especies: Chattonella marina (Subrahmanyan) Y. Hara et Chihara y Gymnodinium catenatum Graham. Chattonella marina fue la especie más abundante con densidades de 14 × 103 a 36 × 103 cél. L-1 a nivel sub-superficial. Gymnodinium catenatum se registró con densidades de 1 × 103 a 19 × 103 cél. L-1 . La temperatura del agua fue homogénea desde la superficie hasta los 20 m de profundidad, con un intervalo de 19.5 a 22.0 °C y de 20.0 a 21.5 °C a finales de marzo y abril respectivamente. En la primera mitad de mayo se inició la estratificación, con una diferencia térmica de 5.0 °C entre la superficie y los 20 m. Los nitratos variaron de 0.5 a 11.0 µM y los ortofosfatos de 0.4 a 2.6 µM. La clorofila a en marzo presentó un valor en superficie de 7.5 mg m-3 y a 20 m de 3.5 mg m-3 , en mayo varió de 2.0 a 7.0 mg m-3 . Se concluye que la aparición de las dos especies observadas en este estudio se asocia a la disminución de los procesos de mezcla en esta bahía

Mass fish die-off during a diatom bloom in the Bahía de La Paz, Gulf of California

An unusual fish die-off occurred during a bloom of diatoms from June 10th July 3rd 2006 in Bahía de La Paz in the Gulf of California. The prevalent organisms were Pseudo-nitzschia spp. (2.4 × 106 cells L1), Thalassiosira eccentrica (2.3 × 106 cells L1) and Chaetoceros spp. (9.65 x 105 cells L1). Three toxic species were identified: P. pseudodelicatissima-complex, P. fraudulenta, and P. pungens. Fucoxanthin was the dominant pigment during the bloom, peaking at 9.3 ?g L1. Sea surface temperature dramatically increased from 19.0 °C to 27.0 °C during the bloom, with inorganic nitrogen (1.0 ± 0.6 ?M) and Si(OH)4 (15.5 ± 8.0 ?M). Low content of domoic acid measured by HPLC-UV from net samples ranged from 24.0 to 52.0 ng per filter and tissue of the chocolate clam Megapitaria squalida (0.55 ?g g1) and the white clam Dosinia ponderosa (0.06 ?g g1). Domoic acid analysis of dead fish tissues was negative. Fish necropsy indicated that death by asphyxia was probably caused by Thalassiosira eccentrica and Chaetoceros spp. Alternate mixing processes and instability of the water column, as well as sudden changes of both temperature and nutrients created conditions for proliferation of the diatoms

Toxinas paralizantes en moluscos bivalvos durante una proliferación de Gymnodinium catenatum Graham en la Bahía de La Paz, México

From February to March 2007 a harmful algae bloom of Gymnodinium catenatum Graham ocurred in Bahía de La Paz, Mexico, with cell densities from 6 x 105 to 2,39 x 106 cells L-1. During this event the toxin concentration and toxin profile of paralytic shellfish toxins in mollusks (Pinna rugosa, Modiolus capax, Megapitaria squalida, Periglypta multicostata, Dosinia ponderosa, and Megapitaria aurantiaca), and in phytoplankton samples were determined. Some physicochemical data were obtained. The average values of the surface temperature and dissolved oxygen were 20.9 ± 0.7 °C and 6.9 ± 0.3 mg L-1. The average concentrations of nitrites, nitrates, ammonium, phosphates, and silicates were 0.22 ± 0.05, 1.04 ± 0.33, 0.89 ± 0.88, 0.81 ± 0.76, and 8.85 ± 1.60 µM, respectively. The concentration of paralytic shellfish toxins in the net phytoplankton samples varied from 4.32 to 79.60 ng saxitoxin equivalents filter-1, identifying 8 toxins, the most abundant being C1 and C2. The highest toxin concentration found in mollusks were 31.14, 37.74, and 25.89 µg STXeq 100 g-1 in M. capax, P. rugosa, and M. aurantiaca, respectively. The variations in the paralytic toxin profile in the different mollusks species are given.De febrero a marzo de 2007, se presentó una proliferación de Gymnodinium catenatum Graham en la Bahía de La Paz (México), con densidades de 6 x 105 a 2,39 x 106 cél. L-1. Durante este evento se determinó la concentración y el perfil de toxinas paralizantes en moluscos bivalvos (Pinna rugosa, Modiolus capax, Megapitaria squalida, Periglypta multicostata, Dosinia ponderosa y Megapitaria aurantiaca) y en muestras de fitoplancton. También se obtuvieron algunos parámetros físicos y químicos. Los valores promedios de la temperatura superficial y del oxígeno disuelto fueron de 20.9 ± 0.7 °C y 6.9 ± 0.3 mg L-1, respectivamente. Las concentraciones promedios de nitritos, nitratos, amonio, fosfatos y silicatos fueron de 0.22 ± 0.05, 1.04 ± 0.33, 0.89 ± 0.88, 0.81 ± 0.76 y 8.85 ± 1.60 µM, respectivamente. El contenido de toxinas paralizantes en las muestras de arrastres de red variaron de 4.32 a 79.60 ng saxitoxina equivalente filtro-1, identificándose 8 toxinas, siendo la C1 y C2 las dominantes. Las máximas concentraciones de toxinas paralizantes en los moluscos fueron de 31.14, 37.74 y 25.89 µg STXeq. 100 g-1 en M. capax, P. rugosa y M. aurantiaca, respectivamente. Se dan a conocer las variaciones en el perfil de toxinas paralizantes en las diversas especies de moluscos

Durinskia yucatanensis sp. nov. (Peridiniales: Kryptoperidiniaceae), una nueva especie de dinoflagelado planctónico, y su hábitat en aguas costeras de Yucatán, Golfo de México

Background: In the coastal waters of the northern Yucatan Peninsula, in the southeastern Gulf of Mexico, numerous pelagic algal blooms have been recorded in the 21st century. In August 2010, an unknown small-sized Peridiniales species caused an intense bloom in the Sisal marina. In subsequent years, it was occasionally found at other sites along the Yucatan coast. Goals: The main objective of the present study was to name this dinoflagellate as a new species and determine its ecological preferences. Methods: Phytoplankton blooms were monitored from August 2011 to September 2014. Fixed cells of the studied species were examined in a JEOL JSM-7600F scanning electron microscope. Its ecological preferences were evaluated using multivariate permutational analysis and generalized additive models (GAM). Results: The name Durinskia yucatanensis (Dinophyceae: Peridiniales) with the thecal plate formula Po X 4’ 2a 6” 5c 4s(?) 5”’ 2”” is proposed for a previously recorded Kryptoperidiniaceae species from the northern Yucatan coastal waters. Dissolved inorganic nitrogen positively correlated with cell abundances for both the exposed coast and marinas, especially in July-August, characterized by high water temperature (31-32 °C). Chlorophyll-a was the only parameter that presented significant spatio-temporal variability among years, months, and sampling sites. The GAM showed that temperature and salinity can predict changes in abundance in different study zones (exposed coast and marinas). The highest values were observed in the Progreso-Chicxulub area along the exposed coast in 2011 and only at Dzilam in marinas during all studied years. Conclusions: The species appears to prefer eutrophic conditions typical for marinas along the northern coast of Yucatan.Antecedentes: En las aguas costeras del norte de la península de Yucatán, en el sureste del Golfo de México, numerosos florecimientos pelágicos de microalgas se han registrado en el siglo 21. En agosto de 2010, una especie pequeña y desconocida de Peridiniales causó un florecimiento intenso en el puerto de abrigo de Sisal. En los años siguientes, se encontró ocasionalmente en otros sitios a lo largo de la costa de Yucatán. Objetivo: Nombrar a este dinoflagelado como una especie nueva para la ciencia y determinar sus preferencias ecológicas. Métodos: Los florecimientos de fitoplancton fueron monitoreados desde agosto de 2011 hasta septiembre de 2014. Las células se examinaron en un microscopio electrónico de barrido JEOL JSM-7600F. Sus preferencias ecológicas se evaluaron mediante análisis permutacional multivariante y modelos aditivos generalizados (GAM). Resultados: El nombre Durinskia yucatanensis (Dinophyceae: Peridiniales), cuya fórmula de placa tecal Po X 4’ 2a 6” 5c 4s(?) 5”’ 2””, se propone para una especie de Kryptoperidiniaceae previamente registrada de las aguas costeras del norte de Yucatán. El nitrógeno inorgánico disuelto se correlacionó positivamente con la abundancia de células, tanto para la costa expuesta como para los puertos deportivos, especialmente en julio-agosto, caracterizados por una alta temperatura del agua (31-32 °C). La clorofila-a fue el único parámetro que presentó variabilidad espacio-temporal significativa entre años, meses y sitios de muestreo. Los GAM demostraron que la temperatura y la salinidad pueden predecir cambios en la abundancia en diferentes zonas de estudio (costa expuesta y puertos deportivos). Los valores más altos se observaron en el área de Progreso-Chicxulub a lo largo de la costa expuesta en 2011 y solo en Dzilam en marinas durante todos los años estudiados. Conclusiones: La especie parece preferir las condiciones eutróficas típicas de los puertos deportivos a lo largo de la costa norte de Yucatán

Occurrence of Cochlodinium fulvescens (Gymnodiniales: Dinophyceae) in the southwestern Gulf of California

The naked dinoflagellate Cochlodinium fulvescens was rarely observed in Bahía de La Paz since 2008. Sporadic observations were made in 2010 and 2012. The species re-appeared from October 2012 to April 2013. Abundance of C. fulvescens ranged from 600 to 45,800 cells L–1 during this period in seawater temperature at 22-27°C and salinity of 35.25- 35.75. This species appeared as single cells or two-celled chains and co-occurred with Cochlodinium polykrikoides at the end of the bloom. C. fulvescens usually occurs in autumn to spring and C. polykrikoides usually occurs in spring to autumn. The main distinguishing morphological characters between these two species are the relative position of the cingulum and sulcus and the morphology of chloroplasts. This provided reliable identification of live cells. Other Cochlodinium species, such as C. faurei, C. pulchellum, and C. rosaceum were also observed in the bay

Variación espacio temporal de la abundancia fitoplanctónica y de la estructura de las asociaciones microfitoplanctónicas en el Sistema Lagunar Magdalena-Almejas durante 1984-1986.

IMPRESO Y PD