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Human activity has caused the decrease of about 20 % of the planet's vertebrate diversity and 25 % in their abundance. Many large and medium-sized herbivore mammals have gone extinct locally, unleashing a cascade of ecosystem changes. The spotted paca (Cuniculus paca) is impacted by hunting and anthropogenic habitat fragmentation and loss. To protect spotted pacas, it is essential to estimate anthropogenic effects on their geographic distribution. Through the use of primary biodiversity data, bioclimatic data, land-cover data, and a human footprint index, we modeled the distribution of C. paca. From 105 candidate models, only one model met our selection criteria. The variables with the highest contribution were the human footprint and annual precipitation. According to the model's performance curves, the spotted paca has low to medium tolerance of anthropogenic pressure. Cuniculus paca tolerates low to medium anthropogenic disturbance, which we hypothesize is related to reduced predator pressure in habitats modified by humans. Accounting for the costs and benefits of anthropogenic disturbance is essential to paca conservation.

Identifying the areas of the world with suitable environmental conditions for the establishment of invasive species represents a fundamental basis for preventing their impacts. One of the most widely used tools for this is ecological niche modeling. Nonetheless, this approach may underestimate the specie’s physiological tolerances since wildlife populations of species usually do not occupy their entire environmental tolerance. Recently, it has been suggested that incorporating occurrences of phylogenetically related species improves the prediction of biological invasions. However, the reproducibility of this technique is unclear. Here, we evaluated the generality of this protocol by assessing whether the construction of modeling units above species level improves the capacity of niche models to predict the distribution of 26 target marine invasive species. For each, we constructed supraspecific modeling units based on published phylogenies by grouping the native occurrence records of each invasive species with the records of its phylogenetically closest relative. We also considered units at the species level, including only the presence of records in the native areas of the target species. We generated ecological niche models for each unit with two methods (minimum volume ellipsoids – MVE and machine learning algorithms – Maxent). In addition, we grouped the 26 target species based on whether or not their niches are unfilled. Our results suggest that the construction of supraspecific units improves the predictive capacity of correlative models to estimate the invasion area of our target species. However, this modeling approach consistently generated models with the higher predictive ability for species with unfilled niches.

Species that exploit the same type of environmental resources are defined as a guild, which have similar needs in the use of food or habitat. It was analyzed the diet of five waterbirds’ offsprings...

Antecedentes: Los rasgos morfológicos y el comportamiento germinativo de las semillas varían dentro de una especie en respuesta a múltiples factores. El conocimiento de esta variabilidad es importante para entender la adaptación de las especies a las condiciones ambientales.Preguntas: ¿La procedencia de las semillas de Cakile edentula afecta los atributos de las semillas? ¿El clima de los sitios de procedencia influye en su variabilidad? ¿La presencia de luz afecta la germinación de las semillas?Especie de estudio: Cakile edentula (Bigelow) Hook. Sitio de estudio: Vegetación de duna costera en la costa norte de la Península de Yucatán, en agosto y octubre de 2017.Métodos: Se colectaron semillas de Cakile edentula en distintas localidades de la costa norte de la Península de Yucatán. En laboratorio se evaluó si la procedencia de las semillas influyó en algunos atributos como peso, contenido de humedad, viabilidad y comportamiento germinativo.Resultados: El sitio de procedencia afectó significativamente el peso y el contenido de humedad de las semillas de C . edentula . Además, las semillas de sitios cálidos y húmedos germinan rápidamente y en mayor proporción que las semillas provenientes de sitios cálidos y secos de la Península de Yucatán. Las semillas de C . edentula germinan preferentemente en oscuridad, independientemente del sitio de procedencia.Conclusiones: Algunos atributos de las semillas de Cakile edentula son afectados por el sitio de procedencia. Las evidencias sugieren que probablemente la variación climática influye en las características iniciales de la historia de vida de esta especie de duna costera.

Snakebite envenoming is a set of intoxication diseases that disproportionately affect people of poor socioeconomic backgrounds in tropical countries. As it is highly dependent on the environment its burden is expected to shift spatially with global anthropogenic environmental (climate, land use) and demographic change. The mechanisms underlying the changes to snakebite epidemiology are related to factors of snakes and humans. The distribution and abundance of snakes are expected to change with global warming via their thermal tolerance, while rainfall may affect the timing of key activities like feeding and reproduction. Human population growth is the primary cause of land-use change, which may impact snakes at smaller spatial scales than climate via habitat and biodiversity loss (e.g. prey availability). Human populations, on the other hand, could experience novel patterns and morbidity of snakebite envenoming, both as a result of snake responses to environmental change and due to the development of agricultural adaptations to climate change, socioeconomic and cultural changes, development and availability of better antivenoms, personal protective equipment, and mechanization of agriculture that mediate risk of encounters with snakes and their outcomes. The likely global effects of environmental and demographic change are thus context-dependent and could encompass both increasing and or snakebite burden (incidence, number of cases or morbidity), exposing new populations to snakes in temperate areas due to “tropicalization”, or by land use change-induced snake biodiversity loss, respectively. Tackling global change requires drastic measures to ensure large-scale ecosystem functionality. However, as ecosystems represent the main source of venomous snakes their conservation should be accompanied by comprehensive public health campaigns. The challenges associated with the joint efforts of biodiversity conservation and public health professionals should be considered in the global sustainability agenda in a wider context that applies to neglected tropical and zoonotic and emerging diseases., Graphical abstract Image 1, Highlights • Distribution and abundance of snakes are expected to be affected by climate change. • Land-use change may also impact snakes but at smaller spatial scales than climate. • Human populations could experience novel patterns and morbidity of snakebite. • Reducing snakebite should be accompanied by actions that protect snake diversity.

Las lagunas costeras son sistemas dominados por la variabilidad ambiental ocasionada por ciclos estacionales o nictémeros, lo cual influye directamente en la composición de especies como la de los peces. El objetivo de este estudio fue evaluar la variación en la composición de la comunidad de peces a 2 escalas temporales y analizar la dieta de especies marinas que utilizan la laguna en alguna etapa de su ciclo de vida. El estudio se realizó en la laguna Carbonera en la costa norte de Yucatán, México. Se recolectaron peces cada 2 h con un chinchorro playero durante un ciclo de 24 h, en campañas bimestrales de diciembre de 2010 a octubre de 2011. Las variables hidrológicas registradas y la comunidad de peces se evaluaron a escala nictémera y estacional, y se observaron cambios significativos en la temperatura y la salinidad. La riqueza específica y la diversidad de peces fueron mayores durante la noche, cuando se registraron especies marinas como los armados (Orthopristis chrysoptera), las corvinas (Bairdiella chrysoura), las mojarras (Eugerres plumieri) y los roncos (Haemulon plumierii). La mayor abundancia se obtuvo durante las horas de luz debido a la presencia de cardúmenes de juveniles de sardina (Harengula clupeola) y especies residentes (Floridichthys polyommus y Fundulus persimilis). Se analizó la alimentación de 10 especies de peces marinos en estadio juvenil, y se identificaron 4 principales gremios tróficos (piscívoros, detritívoros, malacófagos y zoobentófagos). Las especies marinas en estadio juvenil de importancia comercial que utilizan la laguna Carbonera para alimentación son las lisas, las sardinas y los roncos. Por lo tanto, este sistema brinda recursos a juveniles de especies de gran importancia para la pesca artesanal, por lo que es de suma importancia elaborar estrategias de manejo para su protección y conservación.

Mangroves are considered as ecosystems that provide shelter, food and breeding grounds for many groups of inhabiting fauna. Much of the fauna present are organisms in different stages of their life cycle, mostly juveniles. The three-dimensional structure of the mangrove roots and the combination of the aquatic and terrestrial environments are factors that bring together a great diversity. Such diversity within mangrove sites includes aquatic and terrestrial vertebrates and invertebrates such as fish, amphibians, reptiles, mammals and birds. Present within the fauna are representatives of different trophic guilds that perform key functions in the ecosystem, such as pollination, seed dispersal and nutrient recirculation. The food produced by the ecosystem is based on the production of detritus caused by leaf litter and its decomposition, where transformation of energy and accumulation of biomass for higher trophic levels begins with the invertebrates. With regard to breeding activity, many fish families spawn in the mangrove roots (e.g. Fundulidae), or nest in the canopy (herons and cormorants) that provides protection against predators and food for juvenile organisms. Undoubtedly, mangroves function as feeding and breeding grounds that are essential in maintaining populations of marine organisms, especially fish. Many fish species that grow in the mangroves are important for fisheries. Unequivocally, maintaining these breeding sites for marine and terrestrial fauna is crucial to the general functioning of adjacent ecosystems.

Background Biological invasions rank among the most significant threats to biodiversity and ecosystems. Correlative ecological niche modeling is among the most frequently used tools with which to estimate potential distributions of invasive species. However, when areas accessible to the species across its native distribution do not represent the full spectrum of environmental conditions that the species can tolerate, correlative studies often underestimate fundamental niches. Methods Here, we explore the utility of supraspecific modeling units to improve the predictive ability of models focused on biological invasions. Taking into account phylogenetic relationships in correlative ecological niche models, we studied the invasion patterns of three species (Aedes aegypti, Pterois volitans and Oreochromis mossambicus). Results Use of supraspecific modeling units improved the predictive ability of correlative niche models in anticipating potential distributions of three invasive species. We demonstrated that integrating data on closely related species allowed a more complete characterization of fundamental niches. This approach could be used to model species with invasive potential but that have not yet invaded new regions.

Environmental variability often results in morphological plasticity, allowing organisms to acclimate and resist changing environmental conditions. Corals exhibit high morphological variability, possibly influenced by factors such as phenotypic plasticity and hybridization. Pseudodiploria Fukami, Budd & Knowlton, 2012 consists of two species, Pseudodiploria strigosa Dana, 1846 and Pseudodiploria clivosa Ellis & Solander, 1786, which are often differentiated by the colony morphology, number of septa per centimeter, width of valleys, and the presence/absence of coenosteum. In this study, we performed morphological and molecular analyses of 40 Pseudodiploria colonies (20 samples each reef) from the Gulf of Mexico in two reefs Gallega (coastal reef) and Galleguilla (at 2 km of coastline), at the Veracruz Reef System, using univariate analyses of 14 macro- and micro-characters supplemented by examination of mitochondrial (cytochrome b) and nuclear (β-tubulin) sequences. We confirmed the presence of the two Pseudodiploria species based on micro-morphological results. However, 32 colonies of Pseudodiploria presented high phenotypic plasticity at colony and calice levels (11 of the 14 evaluated characters), and molecular variation of β-tubulin gene was higher in the colonies that exhibited high morphological variability. Genetic distances of β-tubulin gene sequences also demonstrated that all colonies collected are most similar to P. clivosa (according to previous studies). Interestingly, we found that colonies collected from a coastal reef had higher variability in morphological characters at colony and calice levels (17 of 20 samples), which may be the evidence of the effect of environmental conditions on phenotypic plasticity of Pseudodiploria colonies.

Correlative estimates of fundamental niches are gaining momentum as an alternative to predict species’ abundances, particularly via the abundant niche-centroid hypothesis (an expected inverse relationship between species’ abundance variation across its range and the distance to the geometric centroid of its multidimensional ecological niche). The main goal of this review is to recapitulate what has been done, where we are now, and where should we move towards in regards to this hypothesis. Despite evidence in support of the abundance-distance to niche centroid relationship, its usefulness has been highly debated, although with little consideration of the underlying theory regarding the circumstances that might break down the relationship. We address some key points about the conditions needed to test the hypothesis in correlative studies, specifically in relation to nichecharacterization and configurations of the Biotic-Abiotic-Mobility (BAM) framework to illustrate the problem of unfilled niches. Using a created supraspecific modeling unit, we show that species for which only a portion of their fundamental niche is represented in their area of historical accessibility (M)—i.e., when the environmental equilibrium condition is violated—it is impossible to characterize their true niche centroid. Therefore, we strongly recommend to analyze this assumption prior toassess the abundant niche-centroid hypothesis. Finally, we discuss the potential of using modeling units above the species level for cases in which environmental conditions associated with species’ occurrences may not be sufficient to fully characterize their fundamental niches.

This study evaluated the response of bat communities, from a taxonomic and functional perspective, to variation in the vegetation and landscape attributes produced by anthropogenic activities. We characterized the following: (1) the community of phyllostomid and mormoopid bats associated with the initial successional stages of a tropical dry forest, (2) the response of these communities to the variation in the attributes of the vegetation and the landscape, and (3) how the seasonality modulates such response. This allowed us to identify potential mechanisms underlying the response of bat communities to human disturbance. Our results showed that the species negatively affected by the anthropoghenic disturbance are those with greater body mass, larger nose-leaves, or a lower wing aspect ratio and relative wing loading, which perform low-speed flights and have high maneuverability and, potentially, a high directionality in their emissions. We also detected a greater sensitivity of bats to changes in the landscape attributes regarding the riparian than the dry forest, and that the effect of anthropic transformation on bats was intensified during the dry season. Then, the continued loss of the original vegetation can lead to a loss of certain groups of bat species in neotropical landscapes, reducing the resilience of the system.

White leg shrimp (Litopenaeus vannamei) is a widely cultured species along the Pacific coast and is one of the most important crustaceans in world aquaculture. The microbiome composition of L. vannamei has been previously studied in different developmental stages, but there is limited information regarding the functional role of the microbiome during the development of L. vannamei. In this study the metatranscriptome in different developmental stages of L. vannamei (larvae, juvenile and adult) were generated using next generation sequencing techniques. The bacterial phyla found throughout all the stages of development belonged to the Proteobacteria, Firmicutes and Actinobacteria, these bacterial phyla are present in the digestive tract and are capable of producing several hydrolytic enzymes, which agrees with high representation of the primary metabolism and energy production, in both host and the microbiome. In this sense, functional changes were observed as the development progressed, in both host and the microbiome, in stages of larvae the most represented metabolic functions were associated with biomass production; while in juvenile and adult stages a higher proportion of metabolic functions associated to biotic and abiotic stress in L. vannamei and the microbiome were shown. This study provides evidence of the interaction of the microbiome with L. vannamei, and how the stage of development and the culture conditions of this species influences the gene expression and the microbiome composition, which suggests a complex metabolic network present throughout the life cycle of L. vannamei.

The Asian tiger mosquito, Aedes albopictus (Skuse) (Diptera: Culicidae), is an invasive species and a vector of numerous human pathogens, including chikungunya, dengue, yellow fever, and Zika viruses. This mosquito had been reported from 36 geographic locations in Mexico by 2005, increasing to 101 locations by 2010 and 501 locations (spanning 16 states) by 2016. Here we modeled the occupied niche for Ae. albopictus in Mexico to characterize the environmental conditions related to its presence, and to generate updated environmental suitability maps. The predictors with the greatest contribution to characterizing the occupied niche for Ae. albopictus were NDVI and annual mean temperature. We also estimated the environmental suitability for Ae. albopictus in regions of the country where it has not been documented yet, by means of: 1) transferring its occupied niche model to these regions and 2) modeling its fundamental niche using global data. Our models will help vector control and public health institutions to identify areas where Ae. albopictus has not yet been recorded but where it may be present. We emphasize that most of Mexico has environmental conditions that potentially allow the survival of Ae. albopictus, which underscores the need for systematic mosquito monitoring in all states of the country.

Introduction: The Río Lagartos lagoon, located in the Ría Lagartos Biosphere Reserve, Yucatán, Gulf of Mexico, is a coastal hypersaline system ca. 80 km long (east-west). It comprises three basins: western (close to Río Lagartos fishermen village), middle (Las Coloradas) and eastern (close to El Cuyo fishermen village), that communicate through very narrow natural channels. Despite several studies have been performed on the vertebrate fauna, the aquatic invertebrates, and especially polychaetes, remain largely unknown. Objective: The objective of this study is to describe the composition and distribution of the benthic polychaete community, and to analyse potential environmental drivers. Methods: The biological material was collected in 16 stations distributed along the lagoon during the rainy season (September 2017). Two replicates per station were obtained using a Ponar standard dredge or cores (6” diameter). Environmental variables such as grain size, organic carbon content in the sediments, and salinity, among others, were measured. Results: A total of 827 specimens belonging to 26 species and 16 families were identified. Of these, 23 species are new records for the Río Lagartos lagoon. Community composition changed between the different basins associated with strong gradients in salinity, subaquatic vegetation (algae and seagrasses) proportions in the samples and grain size. No polychaetes were recorded at the easternmost basin (El Cuyo basin), where salinity was between 67-80 psu. In the rest of the lagoon, the distribution of polychaetes was heterogeneous, especially near the mouth (western basin), where the highest and lowest density, species richness and diversity were recorded. The highest density was found at station 6, where dense algal mats of the genus Avrainvillea dominated. The families Syllidae and Nereididae were the most abundant and widely distributed families in the lagoon. The species Syllis lagunae and Nereis pelagica dominated the western basin and Prionospio heterobranchia and Sphaerosyllis taylori dominated the middle basin. Conclusions: The salinity records associated with some species were well above the top limits previously reported, establishing the euryhaline character of many species in the region. Resumen Introducción: La laguna Río Lagartos, ubicada en la Reserva de la Biosfera Ría Lagartos, Yucatán, Golfo de México, es un sistema costero hipersalino con una longitud aproximada de 80 km (este-oeste). La laguna está conformada por tres cuencas (Río Lagartos, Las Coloradas y El Cuyo) comunicadas entre sí por canales naturales extremadamente estrechos. Aunque existen varios estudios sobre la fauna vertebrada asociada a la laguna, los invertebrados acuáticos, y especialmente la poliquetofauna, son todavía desconocidos. Objetivo: El objetivo de este estudio es analizar la composición y distribución de los poliquetos bentónicos, y su relación con las condiciones ambientales. Metodología: El material biológico fue recolectado en 16 estaciones a lo largo del sistema lagunar durante la época climática de “lluvias” (septiembre 2017). Se tomaron dos réplicas por estación con una draga Ponar standard o un nucleador de PVC (diámetro= 6”). En cada estación se midieron distintas variables ambientales p. ej., granulometría, carbono orgánico en sedimento, salinidad, entre otras. Resultados: Se identificaron 827 ejemplares pertenecientes a 26 especies y 16 familias. De éstas, 23 especies son nuevos registros para la laguna Río Lagartos. La composición de la comunidad varió entre las distintas cuencas de la laguna en relación con importantes gradientes de salinidad, de la proporción de vegetación (algas y pastos) en la muestra y del tamaño de grano. En la cuenca este, El Cuyo, donde el rango de salinidad fue 67-80 ups, no se encontraron poliquetos. En el resto de la laguna, la distribución de los poliquetos fue heterogénea, especialmente cerca de la boca (cuenca de Río Lagartos), donde se registraron los valores más altos y más bajos de densidad, riqueza específica y diversidad. La densidad más alta se registró en la estación 6, donde la muestra estuvo dominada por densos lechos de algas del género Avrainvillea. Las familias Syllidae y Nereididae fueron las más abundantes y ampliamente distribuidas en la laguna. Las especies Syllis lagunae y Nereis pelagica dominaron en la cuenca de Río Lagartos y Prionospio heterobranchia y Sphaerosyllis taylori, en Las Coloradas. Conclusiones: Los rangos de salinidad reportados para algunas de las especies fueron mucho más altos que registros anteriores, estableciendo el carácter eurihalino de varias especies en la región.

"Expression of heat shock protein genes (Hsp) could be determinant for fish to survive an increase of water temperature due to global warming. Coastal lagoons, with their intrinsic high-water temperatures, test the resilience and adaptability of fish populations to environmental change. We analyze the variation in gene expression and genetic variation of 2 endemic Fundulus species in 2 lagoons to the north of the Yucatán Peninsula. We evaluated genetic distances between species using Hsp 70 gene sequences; our results showed low genetic differentiation between both Fundulus species and also showed individuals with high genetic variability, due to non-neutral polymorphisms. Expression of 2 isoforms of Hsp70 genes was higher in F. grandissimus than in F. persimilis. These variations are prompted by water temperature and genetic differentiation of species, induced in the fish thermal stress sensitivity. Our results suggest that both species are sensitive to thermal stress; however, populations exhibit wide genetic expression range and non-neutral polymorphisms, which could be an evidence of an adaptive process to thermal stress. This capacity of the fish populations to adapt to environmental variations could be affecting fish distribution."

Se documenta la presencia de Hypoplectrus ecosur en 2 localidades de la costa noroccidental de la peninsula de Yucatan, Mexico. La evidencia que se presenta en este trabajo permite ampliar el ambito de distribucion geografico de esta especie hacia aguas del golfo de Mexico. Hasta este reporte, la presencia de esta especie solo habia sido confirmada en el extremo noreste de la peninsula de Yucatan, en aguas del mar Caribe.

The Pacific coast of Mexico has 68% of the country’s coastline. It comprises several distinct ecoregions and a wide variety of habitats, a great diversity of coastal types and marine diversity, and several endemic or flagship species that live there permanently or transiently. This natural richness offers many opportunities for development and also provides a great challenge for conservation, since the influence of events acting at different scales, including global warming, urban population growth, industrial development, contamination, and overfishing, is evident clearly. The increasing economic activities enhance population growth in some coastal municipalities. Growing urban areas require new resources, magnifying pressures on the environment that manifest themselves through habitat destruction, greater waste production, and soaring pollution. The coasts of the Mexican Pacific are environments vulnerable not only to a variety of natural phenomena but to human activities whose catastrophic effects on natural communities are unequivocally obvious. This review shows that the Mexican Pacific is a region with serious sustainability challenges. A prominent need is to prioritize factors promoting wellness; previously economic growth has been the main and almost only driver without taking into consideration environmental conservations. The need is for diversifying activities that trigger economic growth, reduce socioeconomic inequality, modernize the infrastructure, and improve public security. At the same time, actions to protect critical socio-ecosystems, with the services that they provide, and to conserve the unique biological diversity they support, must be implemented to address the complex challenges that this region of the world is experiencing.

Prey availability is the major driver of the presence of whale sharks in the aggregation sites around the world. The northern Mexican Caribbean is one of the most important feeding sites for the whale shark (Rhincodon typus, Smith 1828), at which two sources of food are available. Trophic ecology concepts considers that the organisms should satisfy their energy requirements taking not only abundant food but also of good quality. However, scarce studies have been conducted to explorer trophic preferences. Therefore, the aim was to assess the energy density of zooplankton (quality) and zooplankton biomass (quantity) and its spatial and temporal variation related to the whale shark aggregation. Marine surveys were conducted around the three historic zones of more whale sharks sighted, between June and September 2016 to measure physic-chemical parameters, collect zooplankton samples, record whale shark and calorimetric analysis from zooplankton were performed. The whale shark distribution and abundance were mostly regulated by food quantity composed mainly by fish eggs, evidencing the food quality as a lesser factor. However, analyzing food with whale shark presence, the quality food was relevant around July and September when good quality and quantity food was available. Which jointly allowed the largest aggregation of whale sharks. A relationship between these parameters should be constantly evaluated to better understand the trophic function, as also a thermodynamic approach is recommended to be included in future whale shark monitoring.

We modeled the ecological niche of the Yucatan Rattlesnake (Crotalus tzabcan) to map its environmental suitability, estimate its potential distribution, and identify the environmental factors that limit its geographic range within the Yucatan Peninsula (YP). Niche models were built to evaluate, separately and together, the ability of different sets of environmental predictors to explain the distribution of this species. The relative contribution percentage from each variable was calculated from the models with better predictive ability. Response curves were also constructed to observe the influence of predictors on the estimated environmental suitability for C. tzabcan. According to our niche models, even though the distribution of this species covers a large part of the YP, the northwest portion is likely the most environmentally suitable region. By contrast, populations from the north of Guatemala and Belize (south of the YP) are placed within the limits of the species' niche, and the environmental conditions toward the base of the peninsula are not suitable for this species. Precipitation was consistently the most important factor to explain the distribution of C. tzabcan. Although unlikely to directly affect the physiology of C. tzabcan, precipitation affects other factors (e.g., predator, prey, and competitor densities; undergrowth coverage; and relative humidity) that influence survival. Our study contributes new and detailed knowledge of the distribution ecology of a species that was once the most culturally valued in the YP.

Natural and artificial systems containing water resources that have different salinities can be used to generate salinity-gradient energy (SGE). In this paper, the feasibility of implementing SGE in hypersaline coastal lagoons is addressed, taking the coastal lagoon La Carbonera in Yucatan, Mexico, as an exemplary case. A realistic approach to the exploitation conditions and potential that could occur in a SGE plant in these ecosystems is presented. We first analyzed the variability of salinity and temperature in the three characteristic zones of the coastal lagoon and the correlation of these variables with atmospheric forcing. This was done using 1 year records of in situ measurements. Then the theoretical potential for SGE and the intra-annual variability of that potential were assessed considering the three possible harvesting configurations of mixing among fresh, sea, and hypersaline water. Results show that the thermohaline structure may vary significantly for the three locations at different time scales (diurnal to seasonal) depending on the tides, winds, air temperature, atmospheric pressure, and solar radiation. That suggests that the highest annual energy yield would be obtained from alternating throughout the year among the mixing configurations, depending on the specific seasonal thermohaline structure of the lagoon.

Colonies of coral with morphology similar to that of Oculina patagonica de Angelis, 1908 were found in the National Park Veracruz Reef System (NPVRS) along the coast of Veracruz, Mexico in the southern Gulf of Mexico. The identity of these colonies as O. patagonica was confirmed by morphological and molecular analyses. Here, we document the first records of O. patagonica in the Gulf of Mexico. This species is native to the Mediterranean Sea, and could have been accidentally introduced to the Gulf of Mexico through ballast water from ships. In the NPVRS, poor environmental conditions such as polluted waters with high sedimentation, and the capability of O. patagonica to adapt could have facilitated the establishment of this species in the Gulf.

"La Reserva Estatal Ciénegas y Manglares de la Costa Norte de Yucatán (RECMY) fue decretada en el año 2010, sin embargo, aún no se han realizado estudios sobre su composición taxonómica vegetal, considerada una de las propiedades más importantes de las comunidades vegetales. Este trabajo tuvo por objetivo elaborar un listado florístico e identificar los tipos de vegetación y las asociaciones vegetales presentes en la RECMY, analizando su estructura y composición. Se registraron 198 especies, 170 géneros y 61 familias. De ellas el mayor número de especies lo presentaron la familia Fabaceae, seguida por Cyperaceae, Asteraceae y Malvaceae. Seis de las especies registradas se encuentran bajo la categoría de amenazadas y 1 como protegida. Ocho especies son endémicas de la porción mexicana de la provincia biótica de la Península de Yucatán. Se identificaron 4 tipos de vegetación (matorral de duna costera, manglar, petén y selva baja inundable) y 2 asociaciones vegetales (tasistal y tifal). Estos resultados muestran la riqueza de especies y de tipos de vegetación en la RECMY, y son la base para plantear el plan de manejo de la reserva encaminado a su conservación."

Many species of marine fish use coastal lagoons during early stages of their life cycles due to the protection provided by their turbid waters and complex structure of the environment, such as mangroves and mudflats, and the availability of food derived from the high productivity of these sites. In this study, we analyzed the diet of six species of juvenile marine fishes that use a karstic lagoon system in the northwest portion of the Yucatan Peninsula, Mexico. Through stomach contents analysis we determined the trophic differences among Caranx latus, Oligoplites saurus, Trachinotus falcatus, Synodus foetens, Lutjanus griseus, and Strongylura notata. C. latus, O. saurus, S. foetens, and S. notate, which are ichthyophagous species (>80% by number). L. griseus feeds mainly on crustaceans (>55%) and fish (35%), while T. falcatusfeeds on mollusks (>50% bivalves, >35% gastropods). The analysis of similarities (ANOSIM) showed differences in the diet of all species. Cluster analysis, based on the Bray-Curtis similarity matrix revealed three groups; one characterized by the ichthyophagous guild (S. notata, S. foetens, C. latus, and O. saurus), other group formed by the crustacean consumers (L. griseus), and the third, composed by the mollusk feeder (T. falcatus). Species of the ichthyophagous guild showed overlap in their diets, which under conditions of low prey abundance may trigger competition, hence affecting juvenile stages of these marine species that use coastal lagoons to feed and grow.

The presence of arbuscular mycorrhizal fungi (AMF) inwetlands is widespread. Wetlands are transition ecosystems between aquatic andterrestrial systems, where shallow water stands or moves over the land surface.The presence of AMF in wetlands, suggests that they are ecologicallysignificant, however, their function is not yet clearly understood. With theaim of determining the overall magnitude and direction of AMF effect on wetlandplants associated with them in pot assays, we conducted a meta-analysis of dataextracted from 48 published studies. The AMF effect on their wetland hosts wasestimated through different plant attributes reported in the studies includingnutrient acquisition, photosynthetic activity, biomass production and salinestress reduction. As the common metric, we calculated the standardized unbiasedmean difference (Hedges´d) of wetlandplant performance attributes in AMF-inoculated plants versus non-AMF-inoculatedplants. Also, we examined a series of moderator variables regarding symbiontidentity and experimental procedures that could influence the magnitude anddirection of an AMF effect. Response patterns indicate that wetland plantssignificantly benefit from their association with AMF, even under floodedconditions. The beneficial AMF effect differed in magnitude depending on theplant attribute selected to estimate it in the published studies. The nature ofthese benefits depends on the identity of the host plant, phosphorus additionand water availability in the soil where both symbionts develop. Ourmeta-analysis synthetizes the relationship of AMF with wetland plants in potassays and suggest that AMF may be of comparable importance to wetland plantsas to terrestrial plants. Fil: Ramírez-Viga, Thai Khan. Universidad Nacional Autónoma de México; México Fil: Aguilar, Ramiro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Castillo-Argüero, Silvia. Universidad Nacional Autónoma de México; México Fil: Chiappa-Carrara, Xavier. Universidad Nacional Autónoma de México; México Fil: Guadarrama, Patricia. Universidad Nacional Autónoma de México; México Fil: Ramos-Zapata, José. Universidad Autónoma de Yucatán; México

Growth patterns and biochemical analy!'>is al laboratory condilions (temperatUre 28°c' saJinily 22) were analyzed in juveniles wiJd pink shrimp, Farjr/!/tepenaeus duorarum (Burkenroad, 1939), eaught in tlle Gulf of Mexica compared with cultivated (F2) organisms. Shrimp were maintained for 55 days to monitor lhe molt frequency and weight gain over lime. We detennined the frequency of molting and wel ~'ejght gain per day over the experiment lime. Wild shrimp had an average molting frequency of 10 ± 2.03 days with an increase in wet weight af 0.024 ± 0.00 I g day- J; whereas cullivated shrinlp had an average frequency of 11 ± 2.15 days and a growth rate of 0.084 ± 0.002 g day-l. Osmolic capacity was delermined in wild shrimp al 154.85 ± 7.3.47 mOsm kg- 1 and for eultivated al 128.67 ± 42.24 mOsm kg- l . Total protein concentration wus 35.15 mg mI- 1 for wild shrimp, while values for culrinted shrimp werc significanlly differen\ at 112.22 mg nll- l (ANOVA; p < 0.05). Also, an e"periment was conducted to determine the amounl affood consumed befare and after ecdysis in wild and eultivated shrimp. No significan! differences were faund in the food consumption (F = 0.220, P = 0.641) between groups befare and after ecdysis. We detennined fhat foad consumption ntle fel! by 30% during moll and that fceding did not cease when ecdysis oceurs.

Menezes et al. (2010) show that Mugil cephalus Linnaeus, 1758 is different from Mugil liza Valenciennes 1836, the latter being the mullet found along the Atlantic coast of South America. They also suggest that individuals identified as M. cephalus from the northwest Atlantic could represent a population of M. liza in this region, since they doubt the presence of M. cephalus in waters colder than the ones of the West Indies. In order to clarify the presence of M. cephalus in the northwest Atlantic, this study compares meristic and morphometric measurements of M. cephalus and M. liza from the Gulf of Mexico with those obtained by Menezes et al. (2010) for M. liza from South America and for M. cephalus in the Mediterranean Sea. Results show that there are differences in both morphometric and meristic data between the two species. The morphometric measure that differentiates these species is the distance from the snout to the dorsal fin, which is positioned backwards in M. liza compared with M. cephalus. The body width is consistently greater in M. cephalus than M. liza. The meristic character that discriminates between both species is the number of scales in the longitudinal series that, in M. cephalus, ranges from 38 to 43 while in M. liza between 32 to 39. The information presented in this work confirms the presence of M. cephalus in the Gulf of Mexico and the sympatric presence of M. liza is established, even if its abundance is quite low.

article i nfo In the symbiotic association that exists between cleaner shrimp Ancylomenes pedersoni (=Periclimenes peder- soni) and host sea anemones, specificity varies among populations, and shrimp are believed to search among different individual hosts for favourable positions from which to attract client fish. Four laboratory-based exper- iments were conducted to test host selection of A. pedersoni between the following: i) Bartholomea annulata (corkscrew anemone) and Condylactis gigantea (condy anemone), ii) B. annulata, with or without a conspecific resident, iii) a previously known or unknown B. annulata, and iv) a previously known or unknown C. gigantea. Preference (active selection) was distinguished from mere passive association by comparing shrimp acclimation to anemones offered in choice and no-choice (control) situations. The results were analysed using asymmetrical χ 2 contingency tables (in each experiment, n=60) where expected frequencies were obtained with maximum likelihood estimators. Shrimp acclimated more frequently to B. annulata than to C. gigantea, but they acclimated similarly to anemones with or without another resident and to those B. annulata and C. gigantea anemones that were familiar rather than unfamiliar. However, none of the χ 2 values were statistically significant (χ 2 df=1=0.48, 0.19, 0.42, 0.42; overall p>0.45), suggesting that preference may not be responsible for the as- sociation between adult A. pedersoni and its host anemones observed in the field. Differences in the frequency of association may be due to factors other than the active decisions made by shrimp when presented with more than one alternative host.

In view of the relationship between shifts in diet composition and the activity of digestive enzymes in penaeid shrimp, the present study focused on the analysis of digestive trypsin and a-amylase activities of wild Farfantepenaeus. duorarum (Burkenroad, 1939) juveniles and their changes in phenotypic expression, during the molt cycle as endogenous factor and their changes due to different feeding regimes (exogenous factor) in relation with delta C-13 and delta N-15 isotopic signature as an index of food assimilation induced by the seasonal availability of food items in the nursery area. Wild juveniles of F. duorarum were captured from April 2007 to February 2008, in the Celestun coastal lagoon, Yucatan, Mexico. Samplings were carried out considering all quarters of the lunar cycle and in each of the recognized seasons for this region: dry, rainy, and the Nortes (North Wind). Copepods and amphipods were the main source of food for juveniles of E duorarum. Values of delta C-13 in the muscular tissue were near -20 parts per thousand hence the feeding regime of F. duorarum in the lagoon was composed by material of marine origin. Isotopic signature differences were found between the three annual seasons. It is an opportunist generalist organism that is located in the 4(th) trophic level. The digestive enzymatic activities of both trypsin and alpha-amylase in fresh hepatopancreas tissue showed an interaction between season and molt stages (p < 0.05). Activity of the trypsin was highest during the Nortes at molt stage C (140 mU mg(-1) HP) and activity of a-amylase was higher in the Nortes at stage B-2 (674 mU mg(-1) HP). The amylase/trypsin ratio also showed significant interaction between season and molt stages (p < 0.05), with higher values in premolt stages during the rainy and Nortes seasons. Isoforms of these digestive enzymes differed in expression according to the molt stage and also to the season with expression generally being greater at stage C.