Abstract Studies of marine and estuarine red algae (Rhodophyta) are in the early stages in the littoral of the Sian Ka’an Biosphere Reserve, Mexico. The inventory of these organisms was made based on samples obtained from ten sampling during 2009 to 2015 in 22 localities, eight of them in marine and fourteen in estuarine environments. We found 182 species and subspecific taxa of Rhodophyta. The Rhodomelaceae family was the best represented with 65 taxa, followed by Ceramiaceae 13 and Delesseriaceae 12. Of the 182 taxa, 25 are new records Sian Ka’an Biosphere Reserve with Harveylithon rupestre, Spongites fruticulosus, Acrochaetium barbadense, Dasya harveyi, Chondria pumila, Spermothamnion repens, Metapeyssonnelia milleporoides and M. tangerina being new records for the Mexican Caribbean. Of the 182 species, 119 of them are epiphytes, most of them, 54, grew exclusively on other macroalgae, 29 on mangrove roots and 8 on Thalassia leaves. The floristic list is accompanied by data on seasonality, reproduction, habitat, and environment. Species diversity was compared between the winter rains, dry and rainy seasons during the period study. The Rhodophyta of the Sian Ka’an Biosphere Reserve is tropical, and the greatest diversity was found in the marine environment with 83 taxa and during the winter rains with 132. (Rhodophyta Kaan Ka an Mexico 200 201 2 localities environments 18 6 1 12 rupestre fruticulosus barbadense harveyi pumila repens M Caribbean 11 epiphytes 54 macroalgae leaves seasonality reproduction habitat study tropical 132 20 5

Resumo: Os estudos de algas vermelhas marinhas e estuarinas (Rhodophyta) estão em fase inicial no litoral da Reserva da Biosfera de Sian Ka’na, México. O inventário desses organismos foi feito com base em amostras obtidas em oito amostragens no período do 2009 a 2015 em 22 localidades, sendo oito em ambientes marinhos e quatorze em ambientes estuarinos. Neste levantamento, foram identificadas um total de 182 espécies e táxons subespecíficos de Rhodophyta. A família Rhodomelaceae foi a mais representativa com 65 táxons, seguida por Ceramiaceae com 13 e Delesseriaceae com 12. Dos 182 táxons, 25 são referidos pela primeira vez para a Reserva da Biosfera Sian Ka’an, sendo Harveylithon rupestre, Spongites fruticulosus, Acrochaetium barbadense, Dasya harveyi, Chondria pumila, Spermothamnion repens, Metapeyssonnelia milleporoides e M. tangerina também novos registros para o Caribe mexicano. Das 182 espécies, 119 são epífitas, sendo a maioria, 54, aderidas exclusivamente em outras macroalgas, 29 em raízes de mangue e 8 em folhas de Thalassia. A lista florística apresentada é acompanhada de dados sobre sazonalidade, reprodução, habitat e ambiente. A diversidade de espécies foi comparada entre as temporadas de chuvas de inverno, seca e chuvas de verão durante o período estudado. Rhodophyta da Reserva da Biosfera Sian Ka’an săo tropicais, e a diversidade mais representativa foi encontrada no ambiente marinho com 83 táxons e durante as chuvas de inverno com um total de 132 táxons. Resumo (Rhodophyta Kana, Kana Ka na, na Ka’na México 200 201 2 localidades estuarinos levantamento 18 6 1 12 Kaan, Kaan an, an rupestre fruticulosus barbadense harveyi pumila repens M mexicano 11 epífitas maioria 54 macroalgas Thalassia sazonalidade reprodução estudado tropicais 20 5

Abstract The present work describes the phytophysiognomies and inventories the remaining floristic diversity of the Brisas Environmental Protection Area, which is located on the coast of Sepetiba Bay in the state of Rio de Janeiro, Brazil, covering approximately 101 hectares. Three phytophysiognomies were identified and described, namely Restinga, the Lowland Dense Ombrophylous Forest and the Mangrove. Different types of vegetation can be recognized for Restinga, such as beaches and dunes, those located on sandy ridges, in this case represented by Low and High Restinga forests, and the vegetation associated with depressions, such as the Swampy Restinga and Swampy forest. The floristic survey identified 311 species, distributed in 231 genera and 86 families. Herbaceous plants represent 29.26% of the flora, followed by vines (27.75%), trees (27.33%), shrubs (14.46%) and epiphytes (4%). Restinga is home to 81% of the flora, followed by the Lowland Dense Ombrophylous Forest (28.30%) and the Mangrove (2.25%). The most representative families were Fabaceae (38 spp.), Euphorbiaceae (15 spp.), Asteraceae (14 spp.) and Sapindaceae (14 spp.). The area has low floristic similarity with other areas of the state of Rio de Janeiro, but it has a greater grouping with restingas from the state of Rio de Janeiro. Area Janeiro Brazil 10 hectares described dunes ridges forests depressions forest 31 species 23 8 2926 29 26 29.26 flora 27.75%, 2775 27.75% , 27 75 (27.75%) 27.33%, 2733 27.33% 33 (27.33%) 14.46% 1446 14 46 (14.46% 4%. 4 4% . (4%) 81 28.30% 2830 28 30 (28.30% 2.25%. 225 2.25% 2 25 (2.25%) 38 (3 spp., spp spp. 15 (1 spp.. 1 3 292 29.2 277 27.75 7 (27.75% 273 27.33 (27.33% 14.46 144 (14.46 (4% 28.30 283 (28.30 22 2.25 (2.25% ( 29. 27.7 (27.75 27.3 (27.33 14.4 (14.4 (4 28.3 (28.3 2.2 (2.25 27. (27.7 (27.3 14. (14. 28. (28. 2. (2.2 (27. (28 (2. (27 (2

Resumo O presente trabalho descreve as fitofisionomias e inventaria a diversidade florística remanescente da Área de Proteção Ambiental das Brisas, que se localiza no litoral da Baía de Sepetiba, no estado do Rio de Janeiro, possuindo cerca de 101 hectares. Foram identificadas e descritas três fitofisionomias, a saber, Restinga, a mais predominante, a Floresta Ombrófila Densa de Terras Baixas e o Manguezal. Para a Restinga pode-se reconhecer diferentes tipos de vegetação, como a de Praias e Dunas, as situadas sobre Cordões Arenosos, neste caso representadas por Florestas Baixa e Alta de Restinga, e a vegetação associada às depressões, como o Brejo de Restinga e a Floresta Paludosa. O levantamento florístico identificou 311 espécies, distribuídas em 231 gêneros e 86 famílias. As plantas herbáceas representam 29,26% da flora, seguido das trepadeiras (27,75%), arbóreas (27,33%), arbustivas (14,46%) e epífitas (4%). A Restinga abriga 81% da flora, seguida pela Floresta Ombrófila Densa de Terras Baixas (28,30%) e o Manguezal (2,25%). As famílias mais representativas foram Fabaceae (38 spp.), Euphorbiaceae (15 spp.), Asteraceae (14 spp.), Sapindaceae (14 spp.) e Malvaceae (13 spp). A área tem baixa similaridade florística com outras áreas do estado do Rio de Janeiro, porém apresenta maior agrupamento com restingas fluminenses. Brisas Sepetiba Janeiro 10 hectares saber predominante podese pode Dunas Arenosos depressões Paludosa 31 espécies 23 8 2926 29 26 29,26 flora 27,75%, 2775 27,75% , 27 75 (27,75%) 27,33%, 2733 27,33% 33 (27,33%) 14,46% 1446 14 46 (14,46% 4%. 4 4% . (4%) 81 28,30% 2830 28 30 (28,30% 2,25%. 225 2,25% 2 25 (2,25%) 38 (3 spp., spp spp. 15 (1 13 spp) fluminenses 1 3 292 29,2 277 27,75 7 (27,75% 273 27,33 (27,33% 14,46 144 (14,46 (4% 28,30 283 (28,30 22 2,25 (2,25% ( 29, 27,7 (27,75 27,3 (27,33 14,4 (14,4 (4 28,3 (28,3 2,2 (2,25 27, (27,7 (27,3 14, (14, 28, (28, 2, (2,2 (27, (28 (2, (27 (2

Abstract: Floral visitors, particularly pollinators, are important during the life cycle of many orchids. However, despite their biological importance, this information is still unknown in many species, particularly those in mangrove forests. The aim of this research was to study the floral visitors, as well as the pollinators, of the two orchid species Myrmecophila grandiflora and Brassavola nodosa, in a protected natural area with mangrove (RAMSAR), in Tuxpan, Veracruz, Mexico. Ants of different genera were the floral visitors of M. grandiflora, its pollinator is the carpenter bee, Xylocopa nautlana. In B. nodosa, were observed mosquitoes and ladybugs as floral visitors, the pollinator could not be registered, but it is possible that it is a species of moth (Scopula sp.). Finally, this study provides field information about floral visitors and pollinators in two orchid species in mangrove ecosystems and the evidence for pollination.

Resumen: Los visitantes florales, particularmente los polinizadores, son importantes durante el ciclo de vida de muchas orquídeas. Sin embargo, a pesar de su importancia biológica, esta información permanece desconocida para muchas especies, particularmente en ecosistemas de manglar. El objetivo de esta investigación, fue conocer los visitantes florales, así como polinizadores de dos especies de orquídeas Myrmecophila grandiflora y Brassavola nodosa en un área natural protegida con manglar (RAMSAR), en Tuxpan, Veracruz, México. Hormigas de diferentes géneros fueron los principales visitantes de M. grandiflora, su polinizador es la abeja carpintero Xylocopa nautlana. En B. nodosa, se observaron mosquitos y catarinas como visitantes florales. Este estudio provee información de campo acerca de los visitantes florales en dos especies de orquídeas en ecosistemas de manglar y la evidencia para la polinización.

Abstract: Background and Aims: Vascular epiphytes are rare elements of mangrove-dominated forests because sea salinity causes extreme conditions that difficult their establishment. In southern Mexico, most of the studies about the relationships between epiphytes and phorophytes have been carried out in montane forests, while the mangrove forests have received little attention. Our aim was to analyze the relationships between epiphytic species richness and the phorophyte characteristics of Rhizophora mangle, an endangered species under the NOM-059-SEMARNAT- 2010, in the “Pantanos de Centla” Biosphere Reserve located in the north-east of the state of Tabasco. Methods: The relation between species richness of epiphytes and several variables of the phorophytes, such as the aerial root coverage, diameter at breast height (DBH) and height, was evaluated using linear regression models. In addition, phorophytes were divided into five vertical zones to analyze the vertical distribution of the epiphytes using the Sørensen and Margalef indexes. Key results: Seventeen species of epiphytes were recorded. Orchidaceae and Bromeliaceae were the families with the highest species richness (six each). The most representative genus was Tillandsia (Bromeliaceae) with five species. The epiphytic species richness was significantly correlated with phorophyte aerial root coverage and DBH. The phorophyte zones I and III were the most similar because they shared 47% of all recorded species. The zone I (aerial roots) showed the highest epiphyte species richness. In the zone V (outer portion of the canopy) only Selenicereus testudo (Cactaceae) was registered, a species that was found in all five zones of the phorophyte. The mangrove area studied has a relatively high epiphyte richness in spite of the high salinity present in its flooded habitat. Conclusions: Epiphytic species richness was determined by the variation in size of the phorophytes. The aerial roots of R. mangle are an additional niche for the colonization of epiphytes and not just a supporting structure for the unstable soil of the mangrove ecosystem.

Resumen: Antecedentes y Objetivos: Las epífitas vasculares son elementos poco comunes en manglares debido a que la salinidad del agua de mar impone condiciones extremas que dificultan su establecimiento. En el sur de México se han realizado estudios sobre las relaciones epífitas-forófito, principalmente en bosques montanos, pero hay pocos trabajos enfocados en los manglares. El objetivo de este trabajo fue analizar las relaciones entre la riqueza de epífitas y las características de los forófitos de Rhizophora mangle, especie amenazada de acuerdo a la NOM-059-SEMARNAT-2010, en la Reserva de la Biosfera “Pantanos de Centla”, ubicada en el noreste del estado de Tabasco. Métodos: Se evaluó la relación entre la riqueza de epífitas y algunas variables de los forófitos, como la altura, el diámetro a la altura del pecho (DAP) y la cobertura de raíces aéreas, mediante modelos de regresión lineal. Además, los forófitos se dividieron en cinco zonas verticales para analizar la distribución vertical de las epífitas aplicando los índices de Sørensen y Margalef. Resultados clave: Se registraron 17 especies de epífitas. Orchidaceae y Bromeliaceae fueron las familias con mayor riqueza (seis especies cada una). El género más representativo fue Tillandsia (Bromeliaceae) con cinco especies. La riqueza de epífitas estuvo significativamente relacionada con la cobertura de raíces aéreas y el DAP de los forófitos. Las zonas I y III de los forófitos fueron las más similares ya que compartieron 47% del total de las especies registradas. La zona I (raíces aéreas) fue la más rica en especies de epífitas. En la zona V (parte exterior de la copa) solo se encontró a Selenicereus testudo (Cactaceae), especie también hallada en el resto de las zonas. El área de manglar estudiado presenta una riqueza relativamente alta de epífitas pese a la alta salinidad presente en su hábitat inundado. Conclusiones: La variación de los tamaños de los forófitos determinó la riqueza de epífitas. Las raíces aéreas de R. mangle son un nicho adicional para la colonización de epífitas y no solamente sirven como soporte al suelo inestable del ecosistema de manglar.

Epiphytic dinoflagellates were studied in 250 samples from 10 sites in Chelem (a semi-enclosed mangrove lagoon) and Dzilam de Bravo (an exposed coastal locality), on the northern coast of the Yucatan Peninsula, during five surveys in 2008-2009. Temperature, salinity, turbidity, pH, dissolved oxygen, nitrates, nitrites, phosphates, silicates, urea, extractable water column chlorophyll-a, precipitation, and wind speed and direction were measured. The Chelem lagoon system showed minor variability in physical-chemical characteristics compared to the exposed site at Dzilam de Bravo. Dinoflagellates were associated with all the host macrophytes examined including four seagrass species and 33 macroalgal species representing 24 genera. A total of 20 dinoflagellate taxa from 12 genera were recovered from these substrates. The genus Prorocentrum contained the largest number of individual species. The variation in mean epiphytic dinoflagellate abundance over both localities ranged from ~200 to 3500 cells g-1 substrate wet weight. Cell abundances at individual sites, in contrast, ranged from ~100 to >25 000 cells g-1 substrate wet weight. This variation is typical of the patchy distribution of these species in time and space. Overall, Prorocentrum rhathymum (up to 2.41×10(4) cells g-1) was the most abundant species observed across samples. Other abundant species were Bysmatrum caponii (maximum of 1.19×10(4) cells g-1) and Amphidinium cf. carterae (maximum of 3.69×10³ cells g-1). The highest abundances of Gambierdiscus speciesoccurred in May and November (9.90x10³ cells g-1) in Chelem when temperatures ranged from 24.5 to 30.2 oC. The data obtained indicate that the greatest potential for ciguatoxin flux into the food web may occur in protected, low turbulence environments, where salinities are high, nutrients abundant, and water temperatures are between 24 and 31 °C.

Se estudió a los dinoflagelados epífitos en 250 muestras de 10 sitios en Chelem (una laguna rodeada parcialmente por manglar) y Dzilam de Bravo (una localidad costera expuesta), en la costa norte de la Península de Yucatán, obtenidas durante cinco exploraciones en 2008-2009. Se midió la temperatura, salinidad, turbidez, pH, oxígeno disuelto, nitratos, nitritos, fosfatos, silicatos, urea, clorofila-a extraída de la columna de agua, precipitación, así como velocidad y dirección del viento. El sistema de la laguna de Chelem reveló menor variabilidad de las características físico-químicas comparado con la localidad expuesta de Dzilam de Bravo. Los dinoflagelados se encontraron asociados con todos los macrófitos hospederos incluyendo cuatro especies de pastos marinos y 33 de macroalgas representantes de 24 géneros. Un total de 20 taxa de dinoflagelados correspondientes a 12 géneros se obtuvieron de estos sustratos. El género Prorocentrum incluyó la mayor cantidad de especies. La variación en la abundancia promedio de dinoflagelados epifíticos en ambas localidades osciló entre ~200 y 3500 células g-1 de peso húmedo de sustrato. La abundancia de células en los sitios, en contraste, varió entre ~100 y >25 000 células g-1. Esta variación es típica de la distribución en parches de estas especies en el tiempo y el espacio. En general,Prorocentrum rhathymum (máximo 2.41×10(4) células g-1) fue la especie más abundante en las muestras. Otras especies abundantes fueron Bysmatrum caponii (máximo 1.19×10(4) células g-1) y Amphidinium cf. carterae (máximo 3.69×10³ células g-1). La abundancia máxima de Gambierdiscus spp. se presentó en mayo y noviembre (9.90x10³ células g-1) en Chelem cuando la temperatura varió de 24.5 a 30.2 °C. Los datos obtenidos muestran que el mayor potencial para el flujo de ciguatoxinas a través de la red trófica puede encontrarse en ambientes protegidos de turbulencia baja, donde la salinidad es alta, los nutrientes abundantes y la temperatura de agua entre 24 y 31 °C.

Se presenta el primer inventario florístico de diatomeas bénticas para el Sistema Lagunar Bahía Magdalena-Bahía Almejas. Se hicieron muestreos en noviembre de 1999. En las muestras oxidadas y montadas permanentemente, se identificaron 86 táxones, de los cuales 59 son nuevos registros para el área de Bahía Magdalena, y 12 son nuevos para la península de Baja California. Táxones previamente registrados como escasos en otros sustratos son comunes o abundantes sobre macroalgas epífitas de raíces primarias de mangle. Otras species son principalmente formas epipélicas, mientras que 24 son constituyentes comunes del ticoplancton del área. Ciertos táxones parecen ser característicos de sistemas de manglar en general.

The first floristic inventory of benthic diatoms is provided for the Bahía Magdalena- Bahía Almejas lagoon system. Samplings were carried out during November of 1999. The oxydized samples were mounted permanently. Eighty six diatom taxa were identified, out of which 59 are new records for the Bahía Magdalena area, and 12 taxa are new for the Baja California peninsula. Taxa recorded previously as rare in other substrata are common or abundant on the epiphytic macroalgae of mangrove prop roots. Other species are mainly epipelic forms, while 24 are commonly found as tychoplankton in the area. Certain taxa appear to be characteristic of mangrove systems in general. Rev. Biol. Trop. 54(2): 287-297. Epub 2006 Jun 01.

La biomasa y productividad de una comunidad de pastos marinos es útil para determinar el estado ecológico de la costa. Se comparó la biomasa foliar y la densidad de vainas en praderas de Thalassia testudinum Banks & Sol. ex K. D. Koenig, en dos ambientes de la costa del Caribe mexicano (N= 6 cuadrantes/sitio) en Noviembre de 1998. Los valores de vainas y biomasa foliar fueron más bajos en la pradera asociada al manglar, que en la pradera establecida en una laguna arrecifal. Esto probablemente se deba a que las hojas del manglar tuvieron porcentaje más alto de epífitas. Por otro lado, T. testudinum tuvo mayor biomasa que Syringodium filiforme Kütz en la laguna arrecifal.

The biomass and productivity of a seagrass community are useful for determining the ecological status of the coast. Leaf biomass and shoot density in beds of Thalassia testudinum Banks & Sol. ex K. D. Koenig, were compared for two environments in the Mexican Caribbean coast (N= 6 quadrants/site) in November 1998. Shoot and leaf biomass values were lower in the mangrove-associated meadow than in the reef lagoon meadow. This could be related to the higher percentage of epiphytes on mangrove leaves. In addition, T. testudinum had more biomass than Syringodium filiforme Kütz in the reef lagoon.