Abstract: Background and Aims: The reefs of the Parque Nacional Arrecifes de Cozumel constitute one of the main reef formations in Mexico. However, up to date phycofloristic studies that allow detecting changes in the phycofloristic composition or its affinity for some substrates are practically non-existent. Our aim was to determine the taxonomic composition of marine macroalgae present in the Parque Nacional Arrecifes de Cozumel, as well as realize their morphological descriptions and an analysis of their affinity with the substrate they colonize. Methods: The sampling was carried out in October and November 2018 by autonomous diving in 14 reefs of the Parque Nacional Arrecifes de Cozumel. Morphological observations were made using optical and stereoscopic microscopes. The taxonomic determination was made using specialized literature. Key results: Fourty-two taxa were determined: five Ochrophyta, 12 Rhodophyta and 25 Chlorophyta. The best-represented family for Ochrophyta was Dictyotaceae; for Rhodophyta, Ceramiaceae and Rhodomelaceae; and for Chlorophyta, Halimedaceae. New records for the Parque Nacional Arrecifes de Cozumel are described, including Lobophora guadeloupensis as a new record for Mexico. Additionally, four different substrates for the algae were identified: psammophytic (33%), epilithic (32%), epizoic (19%) and epiphytic (16%). The most diverse reefs were La Francesa (LF) and Santa Rosa (SR), whereas the least diverse were Chankanaab (CK) and Tormentos (TM). Conclusions: Although many of the previous records in the area were confirmed in the present study, the presence of 18 new records revealed, on the one hand, the lack of constant monitoring of the algal richness of the region, and on the other hand, the need for morphological descriptions or photographic references that allow contrasting the previous records with the current ones. Given the importance of the Parque Nacional Arrecifes de Cozumel, our results, in addition to offering updated information, represent a starting point for studies in conservation biology.

Resumen: Antecedentes y Objetivos: Los arrecifes del Parque Nacional Arrecifes de Cozumel constituyen una de las principales formaciones arrecifales de México. Sin embargo, actualmente, son prácticamente inexistentes los estudios ficoflorísticos que permiten detectar cambios en la composición ficoflorística o su afinidad por algún sustrato. Por lo tanto, nuestro objetivo fue determinar la composición taxonómica de macroalgas marinas presentes en el Parque Nacional Arrecifes de Cozumel, así como realizar sus descripciones morfológicas y análisis de afinidad con el sustrato que colonizan. Métodos: Los muestreos se realizaron en octubre y noviembre de 2018 en 14 arrecifes del Parque Nacional Arrecifes de Cozumel, mediante buceo autónomo. Se realizaron observaciones morfo-anatómicas utilizando tanto microscopios ópticos como estereoscópicos. La determinación taxonómica se realizó a partir de literatura especializada. Resultados clave: Se determinaron 42 taxa: cinco Ochrophyta, 12 Rhodophyta y 25 Chlorophyta. La familia mejor representada para Ochrophyta fue Dictyotaceae; para Rhodophyta, Ceramiaceae y Rhodomelaceae; y para Chlorophyta, Halimedaceae. Se describen nuevos registros para el Parque Nacional Arrecifes de Cozumel incluyendo a Lobophora guadeloupensis como nuevo registro para México. Adicionalmente, se identificaron cuatro diferentes sustratos para las algas: psamofítico (33%), epilítico (32%), epizoico (19%) y epífito (16%). Los arrecifes más diversos fueron La Francesa (LF) y Santa Rosa (SR), y los menos diversos fueron Chankanaab (CK) y Tormentos (TM). Conclusiones: Aunque muchos de los registros previos en el área fueron confirmados en el presente estudio, la presencia de 18 nuevos registros reveló, por un lado, la falta de monitoreos constantes de la riqueza algal de la región, y, por otro lado, la necesidad de contar con descripciones morfológicas o referencias fotográficas que permitan contrastar los registros previos con los actuales. Dada la importancia del Parque Nacional Arrecifes de Cozumel, nuestros resultados, además de ofrecer información actualizada, representan un punto de partida para estudios en biología de la conservación.

Resumen: Antecedentes y Objetivos: Los sistemas estuarinos veracruzanos cubren 1166 km2 correspondientes a 14 lagunas costeras que constituyen uno de los ambientes acuáticos con mayor diversidad y productividad. Estos son ambientes críticos para especies económicamente importantes, como las macroalgas, que dependen de ellos para su reproducción, alimentación, establecimiento y refugio. Aunque lo anterior los hace candidatos ideales para estudios de biología de la conservación, solo hay dos contribuciones previas a 1995 sobre ficología estuarina. Por tanto, el objetivo de este trabajo fue elaborar un listado sistemático actualizado de las macroalgas estuarinas de Veracruz, junto con un análisis gráfico, que contribuya al conocimiento del grupo y sirva como referencia para posteriores investigaciones biogeográficas, ecológicas o de conservación. Métodos: Se revisó la literatura ficológica publicada de 1963 a septiembre de 2022, así como la base de datos del herbario UAMIZ, para complementar y actualizar los registros. Para la determinación taxonómica de los ejemplares se hizo un estudio de morfología externa. La sinonimia y estatus nomenclatural fueron revisados en AlgaeBase. A partir de los registros obtenidos se realizó un análisis gráfico. Resultados clave: Se presenta una lista actualizada con 113 especies de macroalgas estuarinas: 62 Rhodophyta, 26 Phaeophyceae, Ochrophyta y 25 Chlorophyta, distribuidas en 24 órdenes, 38 familias y 68 géneros. Conclusiones: De acuerdo con lo observado, son evidentes los escasos o nulos estudios ficológicos en ambientes estuarinos veracruzanos, lo que origina un vacío en el contexto de la diversidad de macroalgas estuarinas. Este listado, además de ser una contribución actualizada para Veracruz, es un punto de partida para emprender futuros análisis que ayuden a establecer áreas de importancia biológica en estos ambientes, con el fin de maximizar la diversidad. Además, es evidente la necesidad de un monitoreo ficofloristico constante en los estuarios.

Abstract: Background and Aims: The Veracruz estuarine systems cover 1166 km2, corresponding to 14 coastal lagoons, that constitute one of the aquatic environments with the greatest diversity and productivity. They are critical environments for economically important species, such as macroalgae, which depend on them for their reproduction, feeding, establishment and refuge. Although the above makes them ideal candidates for conservation biology studies, there are only two contributions prior to 1995 on estuarine phycology. Therefore, the objective of this work was to elaborate an updated systematic list of the estuarine macroalgae of Veracruz, together with a graphical analysis, which contributes to the knowledge of the group and serves as a reference for subsequent biogeographical, ecological or conservation research. Methods: Phycological literature published from 1963 to September 2022, as well as the UAMIZ herbarium database, were reviewed to complement and update the records. For the taxonomic determination of the specimens, an external morphological study was carried out. The synonymy and nomenclatural status were reviewed in AlgaeBase. From the records obtained, a graphic analysis was performed . Key results: An updated list with 113 species of estuarine macroalgae is presented: 62 Rhodophyta, 26 Phaeophyceae, Ochrophyta and 25 Chlorophyta, distributed in 24 orders, 38 families and 68 genera. Conclusions: According to what was observed, there are few or no phycological studies in Veracruz estuarine environments, which causes a gap in the context of the diverse estuarine macroalgae. This list, in addition to being an updated contribution for Veracruz, is a starting point to undertake future analyses that help establish areas of biological importance in these environments, in order to maximize diversity. In addition, the need for constant phycofloristic monitoring in estuaries is evident.

RESUMEN Las raíces de Rhizophora mangle proveen un hábitat de guardería para muchas especies debido a la estructura tridimensional que forman, lo cual delimita un área de difícil acceso para depredadores grandes. Adicionalmente, proveen un sustrato duro para muchas especies bentónicas, que se atan a las raíces y contribuyen a la estructura tridimensional del ecosistema. Entre esos organismos, encontramos varias macroalgas, que contribuyen a la productividad primaria del ecosistema y proveen alimento y refugio a los herbívoros. En el presente estudio se identificaron las macroalgas asociadas a las raíces de Rhizophora mangle, en playa Cholón, en las islas del Rosario, Caribe colombiano. Se reportan 36 especies of macroalgas: 21 Rhodophyta, once Chlorophyta y cuatro Phaeophyceae. De esas 36 especies, 19 son nuevos registros para las islas, y otros seis son nuevos registros para Colombia. Este es el primer estudio sobre las macroalgas asociadas a las raíces de manglar en el Caribe colombiano, e ilustra tanto la alta diversidad de la flora marina en el Caribe suroccidental, como la falta de estudios sobre el tema.

ABSTRACT The roots of the red mangrove, Rhizophora mangle, provide a nursery habitat for many species, due to the tridimensional structure they provide, which delimits an area difficult to access to large predators. Moreover, they provide a hard substrate for many benthonic species, which attach to the roots and contribute to the tridimensional structure of the ecosystem. Among these organisms, there are several macroalgae, which contribute to the primary productivity of the ecosystem and provide food and shelter to herbivores. In the present study we identified the macroalgae associated with the roots of Rhizophora mangle, in Cholón beach, Rosario Islands National Park, Caribbean Colombia. We report a total of 36 species of macroalgae: 21 Rhodophyta, eleven Chlorophyta, and four Phaeophyceae. Of these, 19 are new records for the islands, and six are new records for Colombia. This is the first study on the macroalgae associated with mangrove roots in the Colombian Caribbean, and it highlights both the high diversity of the marine flora of the Southwestern Caribbean, as well as the paucity of studies on the topic.

RESUMEN Las macroalgas constituyen un componente muy importante de la biodiversidad marina por su papel en los ecosistemas marino-costeros como productores primarios, competidores por recursos y bioindica-dores de problemas ambientales. El conocimiento de los taxones autóctonos permite vigilar la entrada de especies exóticas e invasoras. Este trabajo surge de la necesidad de actualizar las similitudes de la ficoflora marina, del Atlántico Occidental Tropical y Subtropical, ante los avances del conocimiento de nuevos taxones en los últimos años. Para analizar las diferencias en el área, el Atlántico Occidental Tropical y Subtropical se subdividió en 17 zonas. Hasta el momento, se inventariaron 1615 taxones in-fragenéricos, de los cuales, 368 pertenecen al phylum Chlorophyta, 1050 a Rhodophyta y 197 a la clase Phaeophyceae del phylum Ochrophyta. De ellos, solo 65 se encontraron en las 17 zonas, mientras que 516 fueron registradas en una sola. Los análisis multivariados realizados con todas las especies separan la zona compuesta por Carolina del Norte + Carolina del Sur + Georgia de las demás; las rodofíceas presentan el menor grado de similitud entre las zonas, de modo que quedan más alejadas Bermudas, el Norte del Golfo, Bahamas y Brasil de forma individual, mientras que Jamaica, la Española y Antillas Holandesas + Trinidad-Tobago forman un grupo separado. La región presenta en general una alta similitud en la composición de macroalgas, fundamentalmente en un núcleo central que incluye todo el Caribe, el sur del golfo de México y la Florida.

ABSTRACT Macroalgae are an important component of marine biodiversity for its role in coastal-marine ecosystems as primary producers, competitors for resources, and bioindicators of environmental problems. Knowing native taxa allows watching on foreigner and invasive species. This work arises from the need of updating the similarities of marine macroalgae of the Tropical and Subtropical Western Atlantic, due to the advances in the knowledge of new taxa in the last years. For this analysis, the Tropical and Subtropical Western Atlantic was subdivided into 17 zones. A total of 1615 infrageneric taxa were inventoried so far, of which 368 belong to the phylum Chlorophyta, 1050 to Rhodophyta, and 197 to the class Phaeophyceae of the phylum Ochrophyta. From them, only 65 were found in all zones, while 516 were registered in only one. Multivariate analyses with all the species indicate the separation of North Carolina + South Carolina + Georgia zone from the rest; rhodophyceans present the lower similarity among zones, being Bermuda, Northern Gulf of Mexico, Bahamas, and Brazil more separated individually, while Jamaica, Hispaniola, and Dutch Antilles + Trinidad-Tobago from a distanced group. The region has a high similarity in the composition of macroalgae, mainly from a central core that includes the whole Caribbean, the south of the Gulf of Mexico and Florida.

RESUMEN En los lagos tropicales, los cambios estacionales en la dinámica del plancton son mínimos e irregulares, ya que las condiciones climáticas son bastante estables durante todo el año, en la mayoría de los casos solamente estudios a largo plazo permiten observar patrones en la dinámica del plancton. El lago de Río Cuarto es un lago meromícto tipo maar localizado en las llanuras del norte de Costa Rica, en el pasado se han realizado estudios limnológicos no mayores a un año de muestreo, en este trabajo presentamos datos de la composición del fitoplancton y del zooplancton a lo largo de cuatro años, del 2013 al 2017, con el fin de analizar cambios en la comunidad del plancton en un periodo de tiempo mayor, asociados a variables ambientales. Para el fitoplancton se tomaron muestras subsuperficiales y se fijaron con lugol, y para el zooplancton se hicieron arrastres verticales de 20 m con una red con 64 µm de poro, que se preservaron con formalina y luego se pasaron a alcohol de 95 %. El fitoplancton incluyó 54 taxa, la mayoría fue Chlorophyta, seguidos por Cyanobacteria y Bacillariophyta. Las taxa más comunes fueron: Synechococcus spp., Aphanocapsa sp. Coenochloris fotii, Chlorella sp. y Discostella stelligera. La abundancia total del fitoplancton disminuyó de 2013 a 2017, principalmente debido a una disminución en las Cyanobacteria. El zooplancton estuvo compuesto por 14 taxa: 5 cladóceros, 4 copépodos, 1 díptero y 4 rotíferos. Los más abundantes fueron: Keratella americana, Brachionus falcatus, Eubosmina tubicen y Arctodiaptomus dorsalis. Se observó un cambio en la diversidad y abundancia del zooplancton, al principio (2013-2014) K. americana y E. tubicen se alternaron en dominancia, y luego (2015-2016) A. dorsalis, Diaphanosoma sp. y Ceriodaphnia sp. fueron dominantes, con un regreso de K. americana en el 2017. Los cambios observados en el periodo de estudio parecen estar relacionados con cambios en la condición del lago, pues la termoclina se hundió y el lago se volvió más trasparente durante el estudio. La abundancia, de rotíferos y del cladócero Eubosmina tubicen, disminuyó asociada a una disminución de Cyanobacterias. Esos cambios no siguieron un ciclo anual, más bien parecen cambios que ocurren a largo plazo, tal y como se ha propuesto en la literatura sobre lagos tropicales.

Abstract In tropical lakes, seasonal changes in plankton dynamics are minimal and irregular, since climatic conditions are fairly stable throughout the year, in most cases only long-term studies allow observing patterns in the dynamics of the plankton. Lake Río Cuarto is a maar-type meromic lake located in the plains of Northern Costa Rica, in the past there have been no limnological studies more than a year of sampling, in this work we present data on the composition of phytoplankton and zooplankton over four years, from 2013 to 2017, with the aim of analyzing changes in the plankton community in a longer period, associated with environmental variables. Phytoplankton was studied from subsurface samples, preserved in Lugol’s solution and zooplankton from 20 m vertical hawls of a 64 µm mesh net, and preserved with formaline and later transferred to 95 % ethanol. Phytoplankton composition included 54 taxa, most of them were Chlorophyta, followed by Cyanobacteria and Bacillariophyta. The most abundant were: Synechococcus spp., Aphanocapsa sp. Coenochloris fotii, Chlorella sp. and Discostella stelligera. Total phytoplankton decreased from 2013 to 2017, mainly due to a decrease in Cyanobacteria. Zooplankton comprised 14 taxa, 5 cladocerans, 4 copepods, 1 diptera and 4 rotifers. The most abundant were: Keratella americana, Brachionus falcatus, Eubosmina tubicen and Arctodiaptomus dorsalis. There was a substitution of dominant species through time, at first (2013-2014) K. americana and E. tubicen alternated in dominance, and later (2015-2016), A. dorsalis, Diaphanosoma sp. and Ceridaphnia sp. became dominant, with a return of K. americana by 2017. The changes that occurred during the time of the study seem to be related to changes in the conditions of the lake, since its thermocline deepened with time and became more transparent. The abundance, of rotifers and Eubosmina tubicen, decreased associated to a decrease of Cyanobacteria. Those changes were not cyclical on an annual basis, but seemed to occur more on a long-term basis, as has been recognized earlier in the literature about tropical lakes.

Abstract: Background and Aims: The rocky shore environments of the state of Veracruz are unique sites in which the macroalgal richness has been poorly studied, mainly due to the absence of complete floristic lists and a follow-up of the changes in algal populations. Hence, the goal of this work was to contribute to the knowledge of algae of Veracruz rocky shore environments located in Playa Paraíso, Playa Villa Rica and Playa Muñecos, which are influenced by the foothills of the Neovolcanic Belt. Methods: Seaweeds were collected during rainy (September 2016) and dry seasons (May 2017) on selected rocky shores named “Playa Paraíso” (PP), “Playa Villa Rica” (PVR) and “Playa Muñecos” (PM). Samples were preserved in a seawater and formaldehyde (4%) solution. External and internal morphometric observations were carried out on the thalli, and the species were determined according to specialized taxonomic literature. Key results: A total of 45 species were identified, from which 18 were Chlorophyta, 16 Rhodophyta and 11 Ochrophyta. The most representative families found were Corallinaceae, Rhodomelaceae, Cladophoraceae and Dictyotaceae. The highest richness of species was observed in PP during the dry season. New records are reported for the localities, of which Centroceras gasparrinii, Gracilaria apiculata and G. flabelliformis are new records for the state of Veracruz. Conclusions: The algal flora of the Neovolcanic rocky coast of Veracruz is tropical and houses 31% of the regional algal flora of the state. The new records in each of the localities reflect a gap in the knowledge of the algal richness of this area. As a consequence, it is suggested to continue recording species occurrence in the area in order to integrate the corresponding floristic lists.

Resumen: Antecedentes y Objetivos: Los ambientes de los litorales rocosos del estado de Veracruz, México, son sitios únicos en los que la riqueza específica macroalgal ha sido poco estudiada, ya que se carece de listados florísticos completos y de un seguimiento a los cambios en las poblaciones algales. El objetivo de este trabajo fue contribuir al conocimiento de algas de los ambientes rocosos veracruzanos ubicados en Playa Paraíso, Playa Villa Rica y Playa Muñecos, los cuales están influenciados por las estribaciones del Eje Neovolcánico. Métodos: Las algas se recolectaron durante la época de lluvias (septiembre 2016) y de secas (mayo 2017) en Playa Paraíso (PP), Playa Villa Rica (PVR) y Playa Muñecos (PM). Las muestras se preservaron en una solución de agua de mar y formol al 4%. Se realizaron observaciones morfométricas externas e internas de los talos y se determinaron las especies de acuerdo con literatura taxonómica especializada. Resultados clave: Se determinaron un total de 45 especies, de las cuales 18 fueron Chlorophyta, 16 Rhodophyta y 11 Ochrophyta. Las familias mejor representadas fueron Corallinaceae, Rhodomelaceae, Cladophoraceae y Dictyotaceae. La mayor riqueza de especies se observó en PP durante la época de secas. Se mencionan nuevos registros para las localidades de estudio; de éstos, Centroceras gasparrinii, Gracilaria apiculata y G. flabelliformis son nuevos registros para el estado de Veracruz. Conclusiones: La flora algal del litoral rocoso Neovolcánico de Veracruz es de tipo tropical y alberga 31% de la flora algal regional del estado de Veracruz. Los nuevos registros en cada una de las localidades reflejan que aún prevalece una brecha en el conocimiento de la riqueza algal de esta región. Por lo tanto, se sugiere continuar con el registro de especies en la zona con la finalidad de integrar los listados florísticos correspondientes.

Resumen El objetivo principal fue evaluar la población de macroinvertebrados y fitoplancton como bioindicadores de contaminación en la cuenca del río Chicama, Perú. Se ubicó cuatro estaciones; para macroinvertebrados se evaluó mediante el Trent Biotic Index y Chandler Biotic Score, estableciendo la relación entre las variables (abundancia de taxones) con el coeficiente de correlación de Spearman. La evaluación del fitoplancton se realizó mediante el índice saprobio propuesto por Pantle y Buck. Asimismo, se determinó el índice de Shannon Weaver (H´) y el índice de Simpson (D´). La fauna bentónica con 24 géneros, 18 familias y 9 ordenes, predominancia de Baetis sp., Rhagovelia sp. y Atopsyche sp. El fitoplancton estuvo constituido principalmente por diatomeas (Bacillariophyta) y algunas especies pertenecientes a la clase Chlorophyta, con predominancia de Nitzschia linearis, Fragilaria capucina y Gomphonema sp. Finalmente de los índices evaluados, Trent Biotic Index y Chandler Biotic Score, se determinó contaminación leve a moderada de acuerdo al índice de Pantle y Buck.

Abstract The principal objective was to assess phytoplankton and macroinvertebrates as bioindicators of pollution in Chicama river basin, Peru. Was developed four stations and was assess macroinvertebrates by Trent Biotic Index and Chandler Biotic Score, and it was assess the abundance of taxa related to the variables measures, to establish the relationship between the variables with the Spearman correlation coefficient. The assessment of the phytoplankton are carried out through the index proposed by Pantle and Buck; similarly, the index was calculated from Shannon Weaver (H´) and the index of Simpson (D´). It was registered 24 genera of benthuc fauna, 18 families and 9 orders, with a predominance of Baetis sp., Rhagovelia sp. and Atopsyche sp. and to a lesser degree, in comparison with its predecessors, Tricorythodes sp., Clinotanypus sp., and Simulium sp. In regards phytoplankton was composed mainly by diatoms (Bacillariophyta) and some species belonging to the class Chlorophyta, with predominance of Nitzschia linearis, Fragilaria capucina and Gomphonema sp. Finally, the indices evaluated, Trent biotic index and Chandler Biotic Score determined that there is from slight to moderate pollution according to the index of Pantle and Buck.

Seaweeds are important as photosynthesizers in the trophic chain, human diet and economy. There is scarce research in some regions of Peru. Therefore, it was determined the diversity, distribution, ecology and economic importance of the marine algae of the coast of the La Libertad region. The collection was made in the intertidal and subtidal zones, between 1 and 15 m depth; and deposited in the Herbarium Truxillense (HUT). The material of this institution was reviewed and contrasted with previous studies. The taxonomic determination was made according to the vegetative and reproductive characters. The geographic distribution was considered by provinces (Ascope, Chepen, Pacasmayo, Trujillo, Viru), habitats, tidal zones, coastal ecosystems, depths, and one or more specimens according to the name and number of the main collector, the acronym of the herbarium, the vulgar name and economic importance if they existed. Descriptive phycogeography was estimated by the Feldmann and Cheney indices. 51 species were recorded: 12 Chlorophyta, 7 Ochrophyta and 32 Rhodophyta. The largest number of species was found in Trujillo, Ascope and Chepen, on rocks, intertidal zone and mesolitoral ecosystem. The ficoflora has tropical affinity. Rhodophyta is the most diverse. Chondracanthus chamissoi and Gracilariopsis lemaneiformis present commercial interest in the region.

Las algas marinas son importantes como fotosintetizadoras en la cadena trófica, alimentación y economía humanas. Existen escasas investigaciones en algunas regiones del Perú. Por ello, se determinó la diversidad, distribución, ecología e importancia económica de las algas marinas del litoral de la región La Libertad. La colección se realizó en las zonas intermareal y submareal, entre 1 y 15 m de profundidad; y depositó en el Herbarium Truxillense (HUT). Se revisó el material de ésta institución y contrastó con estudios previos. La determinación taxonómica se realizó según los caracteres vegetativos y reproductivos. Se consideró la distribución geográfica por provincias (Ascope, Chepén, Pacasmayo, Trujillo, Virú), hábitats, zonas de marea, ecosistemas litorales, profundidades, y uno o más ejemplares según el nombre y número del colector principal, el acrónimo del herbario, el nombre vulgar y la importancia económica si existieran. La ficogeografía descriptiva fue estimada por los índices de Feldmann y Cheney. Se registraron 51 especies: 12 Chlorophyta, 7 Ochrophyta y 32 Rhodophyta. El mayor número de especies se encontró en Trujillo, Ascope y Chepén, sobre rocas, zona intermareal y ecosistema mesolitoral. La ficoflora tiene afinidad tropical. Rhodophyta es la más diversa. Chondracanthus chamissoi y Gracilariopsis lemaneiformis tienen interés comercial en la región.

Abstract: There are 3,256 species of phytoplankton reported in Mexico. In the southeast region, particularly in the basins of the Tonalá and Grijalva-Usumacinta rivers, between 155 and 300 species of phytoplankton have been reported. This number of species is considered low for a watershed with the largest water reservoir in Mexico; consequently, this study was focused to the phytoplankton species present in the tropical wetland Chaschoc, located in the basin of the Usumacinta River. Hence, phytoplankton was collected during the low flow of the flooding cycle in 2014 by oblique tows. A total of 129 morphospecies and 6 taxonomic groups were recorded: Cyanophyta (Cyanoprocaryota), Bacillariophyta, Chlorophyta, Cryptophyta, Euglenophyta (Euglenozoa) and Dinophyta (Dinoflagellata). Regarding the number of species, Chlorophyta was the best represented, while the group Cryptophyta was the less represented. In addition, 40 new records are reported for the Grijalva and Usumacinta basins, of which 13 are considered potentially toxic and 42 indicators of pollution and eutrophication. However, it is expected that the registration of species increases with samples in different seasons of the hydrological cycle and other wetlands associated with the Usumacinta River and its tributaries.

Resumen: En México existen 3,256 especies de fitoplancton reportadas. En la región sureste, particularmente en las cuencas de los ríos Tonalá y Grijalva-Usumacinta, el registro varía entre 155 y 300 especies. Este número de especies se considera bajo para una de las cuencas con mayor reserva de agua en el país. Por tal motivo, se planteó el objetivo de reportar las especies de fitoplancton presentes en el humedal tropical Chaschoc, ubicado en la cuenca del río Usumacinta. Para ello, el fitoplancton se recolectó durante el flujo bajo del ciclo de inundación en 2014 mediante arrastres oblicuos. Se registraron 129 morfoespecies de 6 grupos taxonómicos: Cyanophyta (Cyanoprocaryota), Bacillariophyta, Chlorophyta, Cryptophyta, Euglenophyta (Euglenozoa) y Dinophyta (Dinoflagellata). Entre estos, las Chlorophyta fueron el grupo mejor representado, mientras que las Cryptophyta resultaron el grupo con menos especies. En la lista florística se reportan 40 nuevos registros para la cuenca baja del río Usumacinta, 13 especies potencialmente tóxicas y 42 indicadoras de contaminación por materia orgánica o eutrofización. Sin embargo, es esperable que el registro de especies aumente con muestreos en las diferentes temporadas del ciclo hidrológico y otros humedales asociados con el río Usumacinta y sus tributarios.

Abstract: Background: The benthic phycological flora of the Colombian Pacific is found in one of the less known areas of the eastern tropical Pacific, with a total registry of 133 species. Algal biodiversity on the Pacific Coast is relatively low, compared to the Colombian Caribbean, where previous research has registered about 549 species. Goals: This study evaluated the marine macroalgal flora of Tumaco Bay, southern Colombian Pacific, including inventory, species description, and new records in this coastal region. Methods. Algal material was collected from rocky shores and estuarine creeks within the bay between May and December 2009, and March to October 2010. Subtidal algal specimens were collected with scuba. Further, the study recorded additional species and new species locations in the region. Results: The study registered a total of 26 species, of which eight are Chlorophyta, two are Ochrophyta-Phaeophyceae, and 16 are Rhodophyta. These records were distributed in nine orders, 14 families, and 19 genera. The study described the coastal habitats within the bay and the relationships between ecological features and species distribution. Descriptions of each species included morphological data, habitat, and species distribution. Conclusions: Tumaco Bay exhibited low algal diversity (26 species) when compared to studies on Gorgona Island, and along the shores of Costa Rica, Panama, El Salvador, Nicaragua, and Guatemala, with 42, 216, 174, 146, 24, and 16 species, respectively. Similar results have been recorded on the Pacific coasts of Nicaragua and Guatemala, with registries of 24 and 16 algal species, respectively.

Resumen: Antecedentes: La flora de algas marinas bénticas del Pacífico colombiano pertenece a las áreas menos conocidas del Pacífico Tropical Oriental, reportándose en total 133 especies. Esta diversidad algal es relativamente baja, comparada con la registrada en el Caribe Colombiano, que suma 549 especies. Objetivos: El presente trabajo evaluó la diversidad de la flora algal de la bahía de Tumaco, Colombia, haciendo la identificación y descripción de los ejemplares colectados en distintos tipos de ambientes, así como la actualización de los registros ficológicos, para tener un inventario más completo de las algas bénticas de esta región. El estudio describe los hábitats costeros de la bahía y las relaciones entre las características ecológicas y de distribución de las especies. Métodos: El material algal procedente de los esteros y zonas rocosas de la ensenada de la Bahía Tumaco fue recolectado entre mayo a diciembre de 2009 y marzo a octubre de 2010. En la zona submareal el material fue recolectado mediante buceo autónomo. Adicionalmente, se hizo una revisión de literatura de registros ficológicos en la región. Resultados: En total se registraron 26 especies de macroalgas bénticas para la bahía de Tumaco, de las cuales, ocho son Chlorophyta, dos Ochrophyta (clase Phaeophyceae) y 16 Rhodophyta; distribuidas en nueve órdenes, 14 familias y 19 géneros. De cada especie se incluye una descripción con datos morfológicos y morfométricos y tablas que resumen la información del hábitat y distribución geográfica de cada una de ellas. Conclusiones: La bahía de Tumaco presenta baja diversidad de macroalgas bénticas (26 especies) en comparación con estudios en otros ambientes costeros del Pacífico oriental tropical, como la isla Gorgona (Colombia) y costas de Costa Rica, Panamá y El Salvador, con 42, 216, 174 y 146 especies, respectivamente. Resultados similares se presentan en las costas de Nicaragua y Guatemala donde también se han reportado pocas especies de macroalgas bentónicas, 24 y 16, respectivamente.

Abstract: Background: The last floristic survey of marine algae species from Guadalupe Island was published in the 1980s, including a summary of surveys from collections dating back to the beginning of the past century. Goals: To update the species inventory and analyze the macroalgae community on Guadalupe Island. Methods: Four sampling procedures were undertaken, during January, April, and October 2013, and May 2014, from intertidal and subtidal zones, at depths of between 10 and 18m, depending on the locality. Results: 102 species were identified as representatives of the three main taxonomic divisions; 14 species belonging to Chlorophyta, 29 to Ochrophyta, and 59 to Rhodophyta, related to 39 families and 65 genres. Of the organisms found at a specific level, 30 are new records, 13 are taxonomically synonymous, and 59 correspond to previous registries. The Margalef index shows that the highest biologic richness occurred in May 2014, as while the highest diversity also appeared in that same month, as the Shannon-Wiener index indicates. Data were statistically evaluated with the PERMANOVA analysis, showing statistical differences between the analyzed factors (depth, season, zone, and locality), thus demonstrating high heterogeneity at the localities, mainly between the northern and western areas of the island. Conclusions: Guadalupe Island has high species richness and diversity. In accordance to SIMPER analysis, the species that contribute most to the qualitative differences found in the analyzed factors are Zonaria farlowii, Jania rosea, Sargassum palmeri, Dictyopteris undulata, and Padina durvillei.

Resumen: Antecedentes: El último inventario floristico de algas marinas de Isla Guadalupe se publicó en la década de 1980, e incluye una recopilación de trabajos de colecciones de principios del siglo pasado. Objetivos: Realizar un inventario y un análisis actualizado de la comunidad de macroalgas de Isla Guadalupe. Métodos: Se efectuaron cuatro muestreos durante los meses de enero, abril y octubre del 2013 y mayo del 2014, en la zona intermareal y en la submareal, a 10 y 18 m de profundidad, dependiendo de la localidad. Resultados: En total se determinaron 102 especies, entre las que se encuentran representantes de las tres principales Divisiones taxonómicas: 14 especies de la División Chlorophyta, 29 especies de la División Ochrophyta y 59 especies de la División Rhodophyta, las cuales se relacionan con 39 familias y 65 géneros. De los organismos determinados a nivel específico, 30 corresponden a nuevos registros, 13 con sinonimia taxonómica y 59 especies están previamente registradas. De acuerdo con el índice de Margalef, durante mayo del 2014 se presentó la mayor riqueza biológica, en este mismo periodo, según el índice de Shannon-Wiener, se encontró una mayor diversidad. Los datos se analizaron estadísticamente con el análisis PERMANOVA, el cual mostró diferencias significativas entre los factores examinados de profundidad, temporada, zona y localidad de muestreo, lo que indica una alta heterogeneidad entre las localidades, principalmente entre la zona norte y la oeste de la isla. Conclusiones: Isla Guadalupe presenta una gran riqueza y diversidad biológica. De acuerdo con el análisis SIMPER, las especies que más contribuyen a las diferencias cualitativas de los factores analizados son Zonaria farlowii, Jania rosea, Sargassum palmeri, Dictyopteris undulata y Padina durvillei.

Resumo O conhecimento da composição da dieta do molusco de água doce Diplodon enno é de extrema importância para a sua cultura e propagação, permitindo desta forma a recuperação de populações em perigo de extinção no Brasil. As microalgas são a principal fonte de alimento para moluscos filtradores e os uniónidos sendo selecionadas por estes com base nas suas características celulares. O principal objectivo deste trabalho é analisar a composição fitoplanctônica da água e do conteúdo gastrointestinal do molusco D. enno, de forma a desenvolver uma dieta apropriada ao seu cultivo. Para isso, amostras de água e espécimes de bivalves foram recolhidos do rio São Francisco, cidade de Paulo Afonso, Bahia, Brasil. A composição de microalgas encontrada na água e no conteúdo do estômago/intestino foi muito diversa, sendo representada pelas seguintes divisões: Cyanophyta, Chlorophyta, Dinophyta e Heterokontophyta (diatomáceas). Atendendo à abundância relativa de cada divisão de microalgas, podemos afirmar que na água e no trato gastrointestinal Cyanophyta representa 15% e 14%, Chlorophyta 54% em ambos, Heterokontophyta 31% e 27% e Dinophyta 0% and 5%, respectivamente. De acordo com o critério CETESB de classificação de espécies de fitoplâncton, 50% das espécies de Cyanophyta e 15% das de Chlorophyta observadas nas amostras de água foram classificadas como “muito frequentes”, tal como aconteceu para 68% das espécies de Heterokontophyta e 33% das de Chlorophyta nas amostras do conteúdo do trato gastrointestinal. Realçando as espécies presentes, apesar de apenas Coelastrum sp. e Chroococcus sp. terem sido observadas em 100% e 75% das amostras de água, respectivamente, nas amostras de trato gastrointestinal Staurastrum sp., Aulacoseira sp., Scenedesmus sp. e Fragilaria crotonensis foram identificadas em entre 80% e 100% das amostras. Os resultados deste estudo mostram que D. enno se alimenta não apenas de pequenas microalgas clorófitas, devido ao seu pequeno tamanho que possibilita maiores taxas de filtração, como também de diatomáceas maiores, devido a uma possível vantagem nutricional para os bivalves. Assim sendo, uma dieta composta por diatomáceas e pequenas clorófitas poderá ser considerada a mais indicada para a manutenção de populações de D. enno.

Abstract The knowledge on diet composition of the freshwater mussel Diplodon enno (Ortmann) would aid in its culture and propagation allowing, this way, the replacement of natural endangered populations in Brazil. Microalgae are the main food source for captive mussels and unionids have displayed an ability to sort algae based on the cellular characteristics prior to ingestion. The main objective of the present work is to analyze the phytoplankton composition of the water from and of the gastrointestinal contents of the mussel D. enno, as an initial step for development of a suitable rearing diet. Therefore, water samples and bivalve specimens were collected from S. Francisco River, city of Paulo Afonso, Bahia, Brazil. The microalgal composition found in water and stomach/gut content samples was very diverse being represented by the following divisions: Cyanophyta, Chlorophyta, Dinophyta and Heterokontophyta (Diatoms). Concerning the relative abundance of microalgae divisions, it is possible to state, for the water and gastrointestinal contents, that Cyanophyta represents 15% and 14%, Chlorophyta 54% in both, Heterokontophyta 31% and 27% and Dinophyta 0% and 5%, respectively. According to the Brazilian CETESB criteria for phytoplankton species classification, 50% of Cyanophyta and 15% of Chlorophyta species observed in the water samples were classified as “very frequent”, as were 68% of Heterokontophyta and 33% of Chlorophyta species in the gut/stomach tract samples. Focusing at a species level, although in the water only Coelastrum sp. and Chroococcus sp. were observed in 100% and 75% of the samples, respectively, in the gastrointestinal tract the species Staurastrum sp., Aulacoseira sp., Scenedesmus sp. and Fragilaria crotonensis occurred in 80% to 100% of the samples. The present results showed that D. enno feeds not only on small chlorophytes microalgae, due to their convenient size that facilitates higher feeding rates, but also on large size diatoms, due to a possible nutritional advantage for the bivalves. Thus, a diet composed by large diatoms and small chlorophytes microalgae may be considered as the most reasonable for the maintenance of D. enno populations.

O objetivo deste estudo foi avaliar a diversidade de quatro divisões de algas de riachos (Cyanobacteria, Chlorophyta, Ochrophyta e Rhodophyta), comparando os resultados obtidos com o índice de distintividade taxonômica com os padrões de diversidade encontrados em trabalhos anteriores. Os dados foram coletados a partir de um estudo feito em 1000 segmentos de riachos em biomas da América do Norte. O arranjo taxonômico dos táxons foi criado a partir do nível de espécies até o nível de divisão, a fim de se obter a árvore taxonômica, que é utilizada no índice de distintividade taxonômica. Os resultados do índice de distintividade taxonômica mostraram que a diversidade de macroalgas de riachos foi diferente do que é comumente encontrado. Aqui, Ochrophyta foi a divisão com a maior diversidade, enquanto que no estudo original foi a divisão Chlorophyta. Cianobactérias também revelaram resultados diferentes, mostrando a menor diversidade com o índice de distintividade taxonômica, enquanto é frequentemente uma das mais diversas em trabalhos anteriores. A aplicação de métodos estatísticos deve coincidir com os objetivos da pesquisa e ser apropriada para o conjunto de dados coletados. No entanto, diferentes métodos podem complementar análises ecológicas, levando em consideração o aspecto da comunidade que a medida estatística melhor explica.

The main aim of this study was to assess the diversity of four stream algal divisions (Cyanobacteria, Chlorophyta, Ochrophyta and Rhodophyta) by comparing results obtained with taxonomic distinctness index and diversity patterns of previous studies. The data were obtained from a study made in 1000 stream segments in North American biomes. The taxonomic arrangement of the taxa was created from species to division level in order to obtain the taxonomic tree, which is used in taxonomic distinctness index. The results of taxonomic distinctness index showed that stream macroalgal diversity was different from that commonly found. Herein, Ochrophyta was the division with the highest diversity, whereas in previous studies Chlorophyta has been in the first position. Cyanobacteria also presented different results, showing the lowest diversity with taxonomic distinctness index, but it is often one of the most diverse divisions in previous studies. The application of statistical methods should match the research aims and be appropriate to the data set collected. However, different methods can complement ecological analyzes, taking into account what aspect of the community the statistical measure better explains.

Resumo No nordeste do Brasil, as lagoas de estabilização são muito adequadas para o tratamento de águas residuárias por causa da disponibilidade relativamente grande de terra e das condições ambientais (por exemplo, altas temperaturas) favoráveis ao melhor desenvolvimento dos microorganismos. Entretanto, florações de cianobactérias potencialmente tóxicas podem afetar o uso dessas lagoas de tratamento, devido à consequente qualidade inferior do efluente. O objetivo deste estudo foi avaliar a dinâmica das comunidades de fitoplâncton e a ocorrência de cianobactérias em uma lagoa de maturação situada após duas lagoas em série. Temperatura, oxigênio dissolvido, pH, DBO, N e P foram medidos durante um período de quatro meses, durante o qual amostras foram coletadas na superfície e fundo em sete pontos de amostragem da lagoa. As comunidades de fitoplâncton das amostras coletadas foram também identificadas e classificadas utilizando-se um microscópio óptico convencional. Para avaliar os resultados utilizou-se a análise de variância e o teste de Tukey. Para as três divisões de fitoplâncton encontradas (Cyanophyta, Chlorophyta e Euglenophyta), não houve diferença significativa para as amostras de superfície e de fundo de um mesmo mês. Entretanto, ocorreu grande variação para as amostras dos diferentes meses; nos meses de abril e outubro houve uma predominância de Cyanophyta, ao passo que em setembro o predomínio na lagoa foi de Chlorophyta. Os fatores determinantes que favoreceram o predomínio de Cyanophyta foram a baixa carga orgânica superficial aplicada (entre 78 e 109 kg DBO.ha–1.d–1) e N:P ≤ 10. A presença de duas das espécies de Cyanophyta, Oscillatoria sp. e Microcystisaeruginosa, consideradas potencialmente tóxicas, indica que é necessária precaução quando se considera o destino final do efluente tratado e sugere a necessidade de avaliar os riscos e benefícios associados ao uso da tecnologia de tratamento.

Abstract In northeastern Brazil, stabilization ponds are very suitable for wastewater treatment because of the relative great land availability and environmental conditions (e.g., high temperature) favorable for microorganism optimal development. However, blooms of potentially toxic cyanobacteria may affect the use of these treatment ponds due to resulting effluent poor quality. The objective of this study was to evaluate the dynamics of phytoplankton communities and the occurrence of cyanobacteria in a maturation pond located immediately after a series of two ponds. Temperature, dissolved oxygen, pH, BOD, N, and P were measured during a period of four months when samples were collected from the surface and the bottom of 7 sampling points distributed inside the pond. The phytoplankton of collected samples was also identified and classified using a conventional optical microscopy. Analysis of variance and Tukey test were used to evaluate the results. The three phytoplankton divisions found (Cyanophyta, Chlorophyta, and Euglenophyta) did not change considerably through surface and bottom. However, they changed greatly over the sampled months; great dominance of Cyanophyta was found at April and October, while Chlorophyta dominated the lagoon in September. Low superficial organic loads (between 78 and 109 kg BOD.ha–1.d–1) and N:P ≤ 10 were the determinant factors that favored the predominance of Cyanophyta. The presence of two potentially toxic species of Cyanophyta, Oscillatoria sp. and Microcystis aeruginosa, indicates that caution is required when considering the final destination of treated effluent and suggests a need to assess the risks and benefits associated with the use of the treatment technology.

From the inventory data on the marine biodiversity of Cuba's northern and south-eastern coasts collected during the period from July 2011 to April 2012, three new genus and five new species of Cuban algae were for the first time collected: two from the phylum Rhodophyta, one from the phylum Ochrophyta and two from the phylum Chlorophyta. The three genus are Taonia, Rhipiliopsis and Apoglossum, and the five species are Taonia abbottiana, Rhipiliopsis reticulata, Apoglossum ruscifolium, Caulerpa nummularia and Liagora tsengii. The last one is considered rare since it had only been seen in its locality type and more recently found in Cozumel (Mexico). Specimens were collected on rocky substratum from 2 to 15 meters deep. A detailed description on morphology, reproduction and distribution is presented herein as well as illustrations of the five species. Specimens were deposit in the marine collections of the Coastal Ecosystems Research Center (HCIEC), with copies at the National Aquarium of Cuba (HNAC). These findings were made in poorly studied areas of the Cuban archipelago and contribute to know about their distribution in the West Atlantic.

Se registran por primera vez tres nuevos géneros y cinco nuevas especies de macroalgas para Cuba, dos del phylum Rhodophyta, una de Ochrophyta y dos de Chlorophyta, a partir de inventarios de la biodiversidad marina en las costas norte y sur oriental de Cuba, durante el periodo de julio del 2011 a abril del 2012. Los tres géneros son Taonia, Rhipiliopsis y Apoglossum, y las cinco especies son Taonia abbottiana, Rhipiliopsis reticulata, Apoglossum ruscifolium, Caulerpa nummulariay Liagora tsengii. Esta última es considerada como rara dado que hasta el momento solo había sido registrada en la localidad tipo y más recientemente de la Isla Cozumel (México). Los especímenes fueron recolectados sobre sustrato rocoso entre 2 y 15 m de profundidad. Se presenta una descripción detallada de su morfología, reproducción y distribución en el Atlántico occidental, así como ilustraciones de las cinco especies. El material fue depositado en las colecciones marinas del Centro de Investigaciones de Ecosistemas Costeros (HCIEC) con duplicados en las del Acuario Nacional de Cuba (HANC). Estos hallazgos se realizaron en zonas poco estudiadas del archipiélago cubano y contribuyen a ampliar el conocimiento de su distribución en el Atlántico occidental.