Showing papers in "Revista Mexicana De Biodiversidad in 2016"

Checklist of the native vascular plants of Mexico

Abstract: An updated inventory of the native vascular plants of Mexico records 23,314 species, distributed in 2,854 genera, 297 families, and 73 orders. The flora includes 1,039 species of ferns and lycophytes, 149 gymnosperms, and 22,126 angiosperms. On average, the number of synonyms per species is 1.3 (mode = 1). The number of species places Mexico as the country with the fourth largest floristic richness in the world, although among the non-insular countries, by its number of endemic species (about 50%) is second only surpassed by South Africa. The species distribution among higher taxonomic categories, and the richness and endemism values in the 32 states of Mexico are discussed. This compilation allows us to assess the flora's contribution to the overall Mexican biodiversity.

Sobre la relación entre idoneidad del hábitat y la abundancia poblacional bajo diferentes escenarios de dispersión

Abstract: Recent studies based on niche modeling to estimate the distribution of species have provided evidence that the abundance of a species decreases as the distance to the centroid of the climatic niche of the species increases. This empirical relationship is determined using correlative models that relate the presence/absence of a species with abiotic factors under the assumption that species are in equilibrium with its environment, but without taking into account population processes explicitly. The lack of a mechanism that explicitly relates population processes to the niche hinders to interpret results and obtain general conclusions. In this paper the relationship between habitat suitability and abundance under different dispersal scenarios is explored using a virtual species. A clear correlation between abundance and habitat suitability in scenarios without dispersal was found, on the other hand, this correlation decreased as the proportion of individuals who are dispersed increases. These results support the idea that there is a relationship between habitat suitability and abundances, however, they also show that this relationship is modulated by dispersal.

Mindful eating and its relationship with body mass index, binge eating,anxiety and negative affect

Abstract: Mindful eating concerns an awareness of our dietary habits, while its absence is typically associated with anxiety, negative affect and bingeeating. The objective of this study was to analyze these variables in a sample of 216 individuals, divided in four groups: students who practicedsport regularly, university athletes, yoga practitioners and persons suffering from obesity. They were assessed by a semi-structured interview andthe questionnaires MEQ, BES, PANAS and BAI. Statistical analyses included descriptive statistics, Pearson correlation, ANOVA and multipleregression. Results demonstrated that people who have less awareness of their eating habits are generally more overweight, more anxious and havehigher levels of negative affect, while they demonstrate less control over their eating habits. Moreover, these variables can predict binge eating.The model obtained was significant (p < .001) and its predictive capacity through R square corrected was .51. This means that the model predictsa 51% of binge eating from mindful eating, body mass index, anxiety and negative affect.

Coloración atípica en murciélagos: frecuencia y fenotipos en Norte y Centroamérica e islas del Caribe y nuevos casos para México y Costa Rica

Abstract: El registro de murcielagos con coloracion atipica se ha incrementado en los ultimos anos, y la terminologia que se emplea para reconocer los fenotipos es confusa. Los objetivos del presente trabajo fueron: recopilar, clasificar y catalogar los casos de fenotipos atipicos para Norte y Centroamerica e islas del Caribe entre 1930 y 2014, y documentar 9 casos adicionales para Mexico y Costa Rica. Todos los registros sumaron 317 casos de 25 especies, 17 generos y 4 familias, provenientes de 6 paises. Los ejemplares se agruparon en 4 categorias fenotipicas; la mas comun fue manchas blancas, con 274 registros, seguida de albino con 23, no agouti con 11 y descolorido con 4; ademas, 5 ejemplares tuvieron un fenotipo combinado. Los casos adicionales para Mexico corresponden a 5 Artibeus lituratus , un Glossophaga soricina y el primer registro de Sturnira parvidens y de Nyctinomops femorosaccus . Tambien se documento el segundo caso para Costa Rica, Molossus sinaloae . Se desconocen las causas de la coloracion atipica en los murcielagos. Se requiere de estudios geneticos y moleculares para entender su origen y el posible impacto en las poblaciones de murcielagos.

Distribución potencial histórica y contemporánea de la familia Psittacidae en México

Abstract: Resumen Se estimo la distribucion historica y contemporanea para la familia Psittacidae en Mexico utilizando la mayor base de datos integrada hasta ahora y modelos ecologicos de nicho. Los modelos se generaron mediante el algoritmo MaxEnt. Se utilizaron temperatura y precipitacion y se analizo la vegetacion disponible y las areas naturales protegidas decretadas hasta 2015. Los modelos no presentaron errores de omision y permiten contar con estimaciones actuales para cada especie. La mayor distribucion se estima para Amazona albifrons y la menor para Amazona auropalliata. Los resultados indican que todas las especies han perdido habitat, principalmente Ara macao, Amazona auropalliata y A. oratrix. Aunque los bosques tropicales predominan en su distribucion, los bosques templados presentan altos porcentajes para 6 especies. La proporcion de superficie protegida es superior a estimaciones del ano 2000. La estimacion precisa de la distribucion de los psitacidos presentes en Mexico tiene implicaciones de conservacion a nivel internacional, ya que 6 especies son endemicas y 4 tendrian su mayor distribucion potencial en Mexico de acuerdo con cifras de la IUCN. Ante la perdida de distribucion, algunas especies presentan una elevada vulnerabilidad presente y futura, por lo que se debe examinar la relacion entre aptitud ambiental de los modelos y patrones de abundancia poblacional. El uso de modelos de nicho ecologico para evaluar cambios en distribucion asociados al cambio climatico es necesario.

Thermophile mats of microalgae growing on the woody structure of a cooling tower of a thermoelectric power plant in Central Mexico

Abstract: The aims of this research are to identify and describe a periphyton community of thermophilic microalgae in order to expand our knowledge onbiodiversity of a particular environment. Conspicuous biomass of thermophilic microalgae (48◦C) inhabits the cooling towers of the thermoelectricpower plant of Villa de Reyes (Central Mexico). Aggregate samples or microalgal mats were taken in three different areas of the top of a cooling tower,for identification. According to the sequencing analysis of 16S and 18S rDNA genes, the community is dominated by 3 species of Cyanoprokaryota: Chlorogloeopsis fritschii, Arthronema africanum and Chroococcidiopsis sp., previously reported as thermophiles. Also, 2 species of the Chlorophyteor green algae Scenedesmus . Finally, 12 species of diatoms comprise the microalgal community; diatoms were only microscopically identifiedwithin the mats, suggesting that the mats constitute a suitable microenvironment in thermal ambiences. The identified species are of particularinterest because their habitat represents an extreme and an artificial biotope. To the best of our knowledge, this is the first report of thermophiliccommunities of microalgae in Mexico from a power plant; also, this is the first report of A. africanum for the country.

Modelación de la distribución del oso andino Tremarctos ornatus en el bosque seco del Marañón (Perú)

Abstract: Resumen El oso andino (Tremarctos ornatus) es una especie en situacion vulnerable, cuyo habitat se va fragmentando poco a poco por la expansion de las actividades humanas. En el Peru, el bosque seco del Maranon, ecorregion poco investigada a nivel biologico y ecologico, es tambien habitat de la especie. Lamentablemente, en la actualidad esta siendo afectada por la agricultura, ganaderia y construccion de vias de comunicacion, y en el futuro cercano se vera amenazada por la implementacion de actividades economicas de gran envergadura, como las centrales hidroelectricas. Con el objetivo de identificar areas prioritarias para la investigacion y conservacion del oso andino en el bosque seco del Maranon de las regiones Cajamarca y Amazonas, se modelo su habitat utilizando el algoritmo MaxEnt. Se emplearon 60 registros de presencia, asi como 6 variables ambientales. De un total de 6,501.2 km2 de bosque seco del Maranon, el habitat adecuado para el oso andino seria solo de 480.7 km2 (7.4%) y el habitat marginal de 2,418.5 km2 (37.2%). Se identificaron 3 sectores prioritarios de investigacion y conservacion que presentan, ademas, conectividad con bosques montanos y paramos de areas protegidas: Parque Nacional de Cutervo, Area de Conservacion Municipal Huangamarca (Cajamarca), Areas de Conservacion Privada Huiquilla y Huaylla Belen-Colcamar (Amazonas).

Checklist of helminth parasites of wild primates from Brazil

Abstract: The current study is the first attempt to include the many records from wild primate host species from the Helminthological Collection of the Oswaldo Cruz Institute (CHIOC), Rio de Janeiro, Brazil, along with updated information based on literature. We list a total of 50 species of helminth parasites associated with 46 species of wild primates in Brazil. A total of 814 records of helminths in wild primates from Brazil were listed, including 406 samples of helminths stored in the CHIOC. Of these samples, 16 are new host records (NHR). The majority of these helminth species are nematodes with 30 species reported, which corresponds to 60% of the total number of helminths. The helminth species with more host species is the nematode Dipetalonema gracilis (Filarioidea, Onchocercidae), associated to 13 species of primates. The primate species with more reports of helminths in Brazil is Saimiri sciureus (Cebidae), with 16 species (13 nematodes, 3 acanthocephalans). In the current study, 46 species of primates have at least 1 species of helminth recorded, which represents approximately 39% of species of this host in Brazil. Therefore, we can conclude that the helminths documented in wild primates from Brazil are obviously underestimated, since the helminth fauna in the majority of Brazilian primates remains unknown.

Nuevos registros de hongos micorrizógenos arbusculares para México

Abstract: The arbuscular mycorrhizal fungal species Diversispora trimurales, Gigaspora candida and Glomus corymbiforme are reported for the first time in Mexico. These taxa were collected from the rhizosphere of Mimosa lacerata, M. luisana, M. polyantha, and M. purpusii (Leguminosae-Mimosoideae), endemic species to Mexico, 2 of which are distributed only in the Valley of Tehuacan-Cuicatlan, Puebla and Oaxaca. The revised specimens are described in detail and compared with the most similar species of arbuscular mycorrhizal fungi.

Factors affecting nectar sugar composition in chiropterophilic plants

Abstract: Most pollinators prefer the sugars present in the nectar they consume, so it has been hypothesized that they have molded nectar trait evolution. However, nectar-feeding bats do not exhibit preferences for the sugars present in their diet. We analyzed the role that biochemical and ecological factors could play in shaping the nectar traits of chiropterophilic plants. We studied nectar traits and flower production in 49 plant species. We evaluated the relationship between nectar concentration and sugar composition using phylogenetically independent contrasts and if nectar traits were related to flower production using a Manova. We found that 42 species produced high hexoses nectars, and 7 species produced sucrose rich nectars. Phylogenetically independent contrasts showed that nectar concentration was negatively related to glucose content, positively related to fructose content, and was not related to sucrose content. A negative relationship was found from glucose and fructose contents to sucrose content, and glucose content was negatively related to fructose content. Finally, we did not found any relationship between nectar traits and the plants’ flowering strategies. We conclude that bat physiology and the relative low evolutionary time of the interaction between plants and bats may determine the lack of pattern in the nectar characteristics of chiropterophilic plants.

Nymphalidae frugívoras (Lepidoptera: Papilionoidea) asociadas a un ecomosaico agropecuario y de bosque tropical lluvioso en un paisaje del sureste de México

Abstract: Se evaluo si la coloracion de las Nymphalidae frugivoras es un indicador de las unidades del paisaje. Se consideraron 4 condiciones de matriz agropecuaria (vegetacion secundaria madura, vegetacion secundaria joven, pastizales y cercos vivos) comparadas con 4 unidades de bosque (referente ecologico), en Tenosique, Tabasco, Mexico. En cada unidad de paisaje se establecieron 10 trampas Van Someren-Rydon durante 5 dias, aplicando 4 repeticiones. Se identificaron 63 especies, 58 en la matriz agropecuaria y 42 en el referente ecologico. Treinta y siete especies son compartidas, 21 asociadas a areas agropecuarias y 5 solo del referente ecologico. La estructura de la vegetacion afecto la abundancia y composicion, pero no la riqueza de mariposas. Las comunidades de la matriz agropecuaria difirieron > 75% respecto al referente ecologico. Hubo correlacion entre el color y el habitat preferencial. Los patrones tigre y transparente (Danainae) se encontraron en el dosel cerrado. Con excepcion de Adelpha (Limenitidinae) y las de color corteza (Biblidinae), las demas utilizan ampliamente el paisaje, destacando el tipo Hamadryas asociado a ambientes abiertos. El mosaico del paisaje estudiado de remanentes de bosque asociados a una matriz agropecuaria arbolada favorece la conservacion del gremio de lepidopteros y mantiene una alta diversidad de las Nymphalidae frugivoras.

A study on monogenean parasites from the gills of some cichlids (Pisces: Cichlidae) from the Brazilian Amazon

Abstract: The aim of this study was to investigate monogenean fauna in gills of Geophagus camopiensis, Pterophyllum scalare, Satanoperca jurupari, and Satanoperca acuticeps in a tributary from the Amazon River system in Brazil. A total of 2,148 monogenean specimens were collected from 140 fish examined from March 2012 to March 2013, and 84.3% of these fish were parasitized by 1 or more species. Such monogeneans were: Sciadicleithrum geophagi, Sciadicleithrum juruparii, Gussevia spiralocirra and Gyrodactylus sp. However, only G. camopiensis was parasitized by more than 1 species of monogenean, while S. jurupari and S. acuticeps were parasitized by the same species. Prevalence, mean intensity and mean abundance varied among host species and the highest levels of infection were by G. spiralocirra followed by S. geophagi, both parasites with aggregated dispersion. Abundance of monogeneans was not influenced by the size of the host. In G. camopiensis, the infection levels by S. geophagi did not vary during the rainy or drainage seasons. This is the first study on monogenean infections for G. camopiensis and S. acuticeps.

Seed structure and in vitro seedling development of certain Laeliinae species(Orchidaceae)

Abstract: Seeds and seedlings of neotropical Laeliinae species (Cattleya loddigesii, Cattleya tigrina, Hadrolaelia purpurata, Laelia anceps, Schomburgkia gloriosa, and Sophronitis cernua) were studied. The seed germination process and the seedling grown in vitro are described. Seeds of the studied species are unitegmic and have conspicuous thickening in the anticlinal and inner periclinal cell walls. The embryo consists of a relatively long and multicellular suspensor. At first stage of seedling development, the embryo differentiates into a protocorm with rhizoids and meristematic tissue. The budding occurs on the protocorms. The endogenous taproot is produced after the first leaves have emerged. The root is triarch or tetrarch and it possesses velamen. Structural characters related to seed coat, suspensor, ontogeny of leaves, and vascular system of the root are significant indicators for the separation of Laeliinae species.

Effects of establishment of grazing areas on diversity of amphibian communities in tropical evergreen forests and mountain cloud forests of the Sierra Madre Oriental

Abstract: The establishment of grazing areas in humid tropical environments is one of the causes of amphibian population decline. This work evaluates the consequences of the establishment of grazing areas on amphibian communities in an area of the Sierra Madre Oriental using analyses of alpha and beta diversity. Sampling was conducted at 28 locations, 7 in tropical evergreen forest (TEF), 7 in mountain cloud forest (MCF), 7 in tropicalgrazing areas (TGA), and 7 in cloud forest grazing areas (CFGA) using the method of direct sampling. Amphibian diversity is reduced when the grazing areas are established in tropical environments (TGA, 8 species; 7.1 effective species and TEF, 10 species; 7.7 effective species); in contrast,the CFGA has a greater diversity (11 species; 9.3 effective species) compared with MCF (8 species; 3.9 effective species). The most dissimilar composition was found between the 2 communities of undisturbed forests (MCF-TEF; Jaccard dissimilarity 0.78). Establishment of grazing areasin TEF strongly influences the reduction of amphibian populations when compared with MCF.

Anoplurans (Insecta: Psocodea: Anoplura) associated with rodents distributed in the neotropical region of Mexico

Abstract: From April to December of 2010, we performed a cross sectional study in order to collect and identify the species of anoplurans associated with cricetid and heteromyd rodents from montane forests in 5 localities in Guerrero and Oaxaca, Mexico. We analyzed 147 rodents belongingto 10 cricetid species and 1 heteromyd species. A total of 378 sucking lice were collected (189 ♀, 106 ♂, 83 nymphs), distributed in 6 species ( Fahrenholzia microcephala, Hoplopleura emphereia, Hoplopleura ferrisi, Hoplopleura reithrodontomydis, Neohaematopinus neotomae, Polyplax auricularis ) and 2 families (Hoplopleuridae and Polyplacidae). Lice specimens were processed for morphological and molecular identification, using the mitochondrial gene cytochrome oxidase subunit I. Infestations were characterized based on the prevalence and mean abundance. Five of the 6 species were confirmed by molecular analysis. The highest levels of infestation were recorded for H. emphereia (66.7%; 4.4) on Megadontomys thomasi. All localities represent new records for the species studied.

A new species of scorpion of the genus Centruroides (Scorpiones: Buthidae) from the state of Michoacán, Mexico

Abstract: Centruroides ruana sp. nov. is described from Felipe Carrillo Puerto, from the Buenavista Municipality in the state of Michoacan, Mexico. The new species was compared with C. balsasensis Ponce-Saavedra & Francke, 2004, C. infamatus Koch, 1844, and C. limpidus (Karsch, 1879), which are both morphologically its closest relatives and geographically proximate. The description includes the male holotype, with 7 male and 8 female paratypes. A supplementary morphometric analysis is also presented allowing to distinguish the 4 species.

Cloud forests on rock outcrop and volcanic soil differ in indicator tree species in Veracruz, Mexico

Abstract: The tropical montane cloud forest (TMCF) of central Veracruz, Mexico, predominantly grows on volcanic substrate from the Quaternary (2–0.08 Mya), but in very small areas it grows on shallow soils over limestone rock outcrops from the Cretaceous (90 Mya). Our objective was to contrast the vegetation structure and tree species composition of forest communities growing on rock outcrops (FOR) with nearby forests on prevalent volcanic soil (FOV). Results show that species richness and vegetation structure were similar between FOR and FOV. However, a clear difference was revealed by indicator species analysis (ISA), and multinomial classification model (CLAM). ISA and CLAM, respectively, identified 14 indicators and 13 specialists in FOR, whereas, they identified 7 indicators and 14 specialists in FOV. Some FOR indicators were Cercis canadensis, Clusia guatemalensis, Garrya laurifolia, Ostrya virginiana and Quercus pinnativenulosa . Some FOV indicators were Carpinus tropicalis, Clethra macrophylla, Liquidambar styraciflua and Quercus xalapensis ; these species are also common in several Mexican TMCF. Our study demonstrates that the tree community on rock outcrops differs from the surrounding forest on volcanic soils; this is of particular interest because of its different species assemblage and contribution to the high beta diversity of the region.

Primer registro de Agaricus bisporus (Basidiomycota, Agaricaceae) silvestre en Tlaxcala y Veracruz, México

Abstract: El hongo conocido popularmente como champinon, Agaricus bisporus , es la especie comestible mas cultivada comercialmente en el mundo. A pesar de su importancia y de que se ha incluido en listados de diferentes estados de Mexico, su presencia de forma silvestre no se habia corroborado. El objetivo de este trabajo fue determinar si esta especie crece de manera silvestre en Mexico. Se realizaron recolectas en los estados de Tlaxcala y Veracruz, y se aislaron 7 cepas a partir de ejemplares silvestres. Se obtuvieron basidiomas de dichas cepas cultivadas en un sustrato a base de composta. Los ejemplares silvestres que se depositaron en el Herbario XAL, y los obtenidos en cultivo, se estudiaron macro y micromorfologicamente. La cepa IE 623 se utilizo para obtener la secuencia de la region ITS del ADN ribosomal. Los ejemplares revisados coinciden morfologicamente con A. bisporus y presentan en promedio 63.4% de basidios bisporicos. La secuencia de ADN corroboro la determinacion taxonomica, y de acuerdo con los analisis de similitud y filogeneticos se concluyo que la cepa proviene de un ejemplar silvestre y no de una cepa comercial cultivada. Las cepas de A. bisporus silvestres en Mexico podrian aportar germoplasma para mejorar su cultivo comercial.

Partial albinism in Rhinelepis aspera from the Upper Paraná Basin, Brazil, with a review of albinism in South American freshwater fishes

Abstract: This study reports a case of partial albinism in Rhinelepis aspera from the Aguapei River, Upper Parana Basin, Brazil and provides a review of albinism cases in freshwater fishes from South America. The captured specimen has depigmentation throughout almost its entire body, with pigmented eyes and little dark spots on the dorsal and caudal fins. It is an adult male, and we suggest that due to the benthic habitat, it would be able to reach adult size, avoiding predators. The review shows a scarcity of this phenomenon in nature.

New molecular data on subcutaneous Philornis (Diptera: Muscidae) from southern South America suggests the existence of a species complex

Abstract: The taxonomic identification of species in the genus Philornis Meinert (Diptera: Muscidae) has been based primarily upon analysis of morphological characters. However, relying solely on morphology has led to frequent species misidentification. This has been empirically demonstrated when specimens identified morphologically as Philornis seguyi have been reclassified as Philornis torquans based on DNA sequences of the second ribosomal internal transcribed spacer (ITS2), showing that the morphologic distinction between these 2 species is extremely challenging. Herein, new molecular data on specimens assigned to P. torquans and P. seguyi from the type locality of P. seguyi (Misiones province, Argentina) were analyzed. The ITS2 sequences obtained differed from those previously reported for Philornis, increasing to 3 the number of documented genotypes of flies morphologically indistinguishable from P. torquans. These results strongly suggest that subcutaneous Philornis spp. from southern South America could represent a species complex (P. torquans complex).

El uso de espinas del tallo en la identificación de las especies de Neobuxbaumia (Cactaceae)

Abstract: Este estudio evaluo la morfometria de variables de orientacion y tama˜no de las espinas, con el objetivo de indagar sobre la utilidad de lospatrones de espinacion en la identificacion de las especies del genero Neobuxbaumia (Cactaceae: Cactoideae: Echinocereeae). Este analisis seapoyo en un procedimiento de determinacion taxonomica tradicional y en herramientas de estadistica multivariada. Las variables se registraron encategorias preestablecidas en funcion de la organizacion de la areola. Se obtuvieron estadisticos circulares basicos y se construyeron los graficosdescriptivos que representan los patrones de espinacion. Se aplico un analisis canonico discriminante y un clasificatorio a partir de la asignacion–a priori– de especies. La capacidad para asignar correctamente los individuos dentro de su especie fue de 89.6%, en promedio. La orientacion yla longitud de las espinas mostraron potencial para identificar a la mayoria de las especies de Neobuxbaumia , ademas de la especie relacionada Pseudomitrocereus fulviceps . El uso complementario de otros atributos morfologicos vegetativos permite una identificacion mas robusta de lasespecies, como se refleja en la clave de identificacion incluida. Se considera de valor taxonomico el reconocimiento de patrones de espinacion paraidentificar especies en otros grupos de cactaceas en ausencia de estructuras reproductivas.

Situaciones que generan ansiedad en estudiantes de Odontología

Abstract: Se ha identificado que las altas exigencias academicas que se demanda a los estudiantes dentro del ambito universitario puede llevarlos a perder el control y la forma de afrontar los problemas, llegando incluso a presentar altos niveles de ansiedad y depresion, asi como una serie de conductas no saludables que llegan a afectar la permanencia y el rendimiento escolar de los universitarios. De acuerdo con estas consideraciones, en el presente trabajo se plantea la importancia de conocer las situaciones que generan respuestas de ansiedad en 87 estudiantes de Odontologia de la FES Iztacala de la UNAM, con edades entre los 17 y 31 a˜nos, a quienes previamente se les habia aplicado el ISRA de Miguel-Tobal y Cano-Vindel, y que fueron identificados como poseedores de altos niveles de ansiedad, lo que nos condujo a realizar un analisis cualitativo para determinar las situaciones en las que prevalece un mayor nivel de ansiedad y los tipos de respuesta ansiosa;tambien se compara por sexo y semestres. Los resultados mostraron las situaciones de examen y de hablar en publico como las de mayor relevancia para generar ansiedad; asimismo, se encontro que las mujeres del tercer semestre y los hombres del quinto semestre son los mas ansiosos, sobresaliendo las respuestas de tipo fisiologico.

Estructura y composición de la comunidad de escarabajos (Coleoptera: Scarabaeoidea) en el cerro Chacateca, Zapotitlán, Puebla, México

Abstract: Resumen Se estudio la abundancia, riqueza y diversidad de la fauna de Scarabaeoidea en el cerro Chacateca, Zapotitlan, Puebla. Se realizaron muestreos en la epoca de sequia y de lluvias, en 3 sitios ubicados en diferentes cotas altitudinales, con vegetacion y textura de suelo particulares. Mediante el uso de necrotrampas, coprotrampas, trampas de fruta, trampas de luz y recolecta directa se registro un total de 1,300 individuos de 16 generos y 25 especies. Se registraron cambios significativos en la abundancia y diversidad entre las 2 epocas de recolecta, encontrando mayor diversidad en la epoca de secas. La similitud de la comunidad de escarabajos entre epocas fue baja. La abundancia de los escarabajos copronecrofagos fue significativamente diferente entre sitios. El sitio de menor altitud mostro menor similitud en la composicion de especies en relacion con los sitios de mayor altitud. Los escarabajos fitofagos fueron analizados unicamente en los sitios con menor y mayor altitud, donde presentaron diferencias significativas en su abundancia y diversidad, ademas de una baja similitud en la composicion de especies.

Temperature treatments boost subclinical infections of Batrachochytrium dendrobatidis in a Mexican salamander (Pseudoeurycea leprosa)

Abstract: The first record about the pathogenic fungus Batrachochytrium dendrobatidis in Mexican plethodontid salamanders dates back to the 1970s. However, little is known of the patterns of infection in wild populations and the effects of changes in temperature on the degree of infection. This work quantified Bd infection in a population of Pseudoeurycea leprosa in La Malinche National Park, Puebla, Mexico from June 2011 to September 2012. A total of 160 adult salamanders were experimentally exposed to temperatures of 10, 15, 20, 23, 25, or 28◦C for 10 weeks. The results of this study revealed that: (1) the population of P. leprosa in La Malinche National Park is infected with Bd throughout the year at a low prevalenceof between 0 and 17%; (2) 20.6% of the salamanders that were Bd negative at the time of collection expressed chytridiomycosis after exposure to the experimental temperature treatments; (3) temperature was the cause of death in each treatment, with temperatures of 25 °C and 28 °C affecting the survival of P. leprosa ; (4) the infection load in certain P. leprosa individuals exhibited cycles of increasing and decreasing zoospore genomic equivalents over time.

Ecología trófica de la lagartija Xenosaurus mendozai (Squamata: Xenosauridae) en el estado de Querétaro, México

Abstract: Se determino la ecologia trofica de la lagartija Xenosaurus mendozai en Queretaro, Mexico, identificando la importancia relativa de las presas consumidas y evaluando las diferencias intersexuales en la composicion de la dieta, a lo largo de un ano. Para ello, se calculo su valor de importancia (IX), se evaluo el nivel de especializacion mediante el indice de Levins, asi como el solapamiento mediante el indice de Pianka. Los analisis del contenido del tracto digestivo indican que son insectivoras y su dieta se basa principalmente en 12 ordenes, de los cuales las larvas de lepidopteros, los coleopteros y los ortopteros representan mas del 60% de su dieta; por lo que la tendencia de esta poblacion es hacia la especializacion (BA= 0.015), con un alto indice de solapamiento entre machos y hembras (OMH= 0.946). En terminos generales, la conformacion de la dieta de esta especie es similar a lo registrado en otras especies del genero, lo que puede estar determinado por el uso del microhabitat. Sin embargo, se requiere de estudio de disponibilidad de presas para describir con mayor precision las preferencias alimentarias, asi como para realizar pruebas experimentales que permitan determinar si existe preferencia por algun tipo particular de presas.

Historia florística y ambiental del bosque mesófilo de montaña en el centro-occidente de México durante la pequeña edad de hielo

Abstract: Por medio de tecnicas paleoecologicas se documento la historia floristica y ambiental del bosque mesofilo de montana con presencia relictual de Acer saccharum subsp. skutchii del centro-occidente de Mexico. La reconstruccion de la vegetacion de los ultimos 720 anos se efectuo a traves del nucleo de sedimento (TLP-N2) de 37 cm de profundidad; los indicadores geoquimicos utilizados incluyen susceptibilidad magnetica, fluorescencia de rayos X y perdida por ignicion; mientras que el microcarbon fue empleado como indicador de incendios forestales. Los resultados muestran el inicio de la pequena edad de hielo a partir de 1341-1858 dC, con la presencia de abundantes taxones lenosos y pteridofitas. El periodo mas seco se presento de 1653-1720 dC, etapa que corresponde con el minimo de Maunder en la actividad solar; este se caracteriza por un aumento de polen de herbaceas como Poaceae, Piper y Arisaema. Las condiciones ambientales actuales se establecieron a partir de 1871 dC, que se asemeja con las condiciones del periodo calido medieval (1230-1319 dC), mientras que la actividad humana relacionada con la presencia de polen de maiz se infiere desde hace 720 anos. Los resultados del registro paleoecologico sugieren que el bosque mesofilo ha sido fluctuante y resiliente durante el ultimo milenio.

Integrando la estructura taxonómica en el análisis de la diversidad alfa y beta de los escarabajos Melolonthidae en la Faja Volcánica Transmexicana

Abstract: Se evalua la diversidad alfa y beta (disimilitud) de escarabajos Melolonthinae, Rutelinae y Dynastinae registrados en 8 estudios faunisticos de la Faja Volcanica Transmexicana. La diversidad alfa se analizo utilizando 2 medidas: la riqueza de especies y la diversidad taxonomica. Como se esperaba, la diversidad taxonomica y la riqueza de especies siguen tendencias distintas. La comunidad con mayor riqueza de especies (Popocatepetl) mostro una baja diversidad taxonomica, en tanto que en comunidades con valores comparativamente bajos de riqueza (Huehuetitla, Zapata, La Malinche, Iztaccihuatl y Pico de Orizaba), la diversidad taxonomica resulto con valores bajos y altos. La diversidad beta tambien se evaluo con 2 medidas: disimilitud de especies y disimilitud taxonomica. La disimilitud de especies vario del 61% al 94%, mientras que la disimilitud taxonomica vario del 29% al 68%. De acuerdo a lo esperado, se encontro una relacion significativa entre la disimilitud de especies y la disimilitud taxonomica, y no se detectan correlaciones entre la disimilitud y la distancia geografica entre localidades. Este estudio remarca la importancia del uso complementario de medidas de diversidad que consideren la informacion evolutiva de las comunidades, principalmente en zonas con una compleja historia biogeografica.

Spider cyberdiversity (Araneae: Araneomorphae) in an ecotouristic tropical forest fragment in Xilitla, Mexico

Abstract: The diversity of araneomorph spiders in an ecoturistic tropical forest remnant of approximately 40 ha is described. A 1-ha plot with homogeneous vegetation was established. Six sampling methods covered all microhabitats, except tree canopy. Four expeditions were conducted from August 2011 to June 2012. In a total of 485 samples, 4,118 adult specimens representing 205 morphospecies were collected. Nonparametric richness estimates varied between 229 and 295 species. All collected morphospecies and species were documented with 2,233 digital images available at www.unamfcaracnolab.com. These images are intended to expedite species identification and to allow comparisons of taxa not formally described. Morphospecies identifications included: 91 species, 12 as similar to a described species, 86 to genus and 16 to family. Differences between seasonality and species collected revealed that March and June were similar in composition and were better represented in both number of species and adult specimens than August and November, although the collecting effort was the same. The similarity ranged between 0.35 and 0.71 among seasons.

Diversidad algal de un ambiente extremo: el manantial geotermal Los Hervideros, México

Abstract: Resumen El presente trabajo describe la diversidad algal del manantial geotermal Los Hervideros, Michoacan, Mexico, asi como su distribucion en relacion con el gradiente de temperatura. Este manantial forma parte del sistema hidrotermal Los Azufres, localizado en el mismo estado, el cual es afectado por la actividad volcanica de la Faja Neovolcanica Transmexicana. La identificacion de las especies fue morfologica y se midieron parametros fisicoquimicos como la temperatura, la conductividad especifica y el pH. La temperatura del agua oscilo entre los 22.2 y 85.2 °C, presento una conductividad especifica de 3,400 a 4,430 μS cm-1 y un pH de 7.5 a 8.0. Las especies que dominaron los crecimientos fueron de la clase Cyanophyceae, con los generos: Arthrospira sp., Synechococcus sp. y Synechocystis sp. en temperaturas de 22 a 76 °C. En cuanto a las especies de Bacillariophyceae, se registraron: Achnanthidium exiguum, Halamphora veneta, Anomoeoneis costata, Diploneis elliptica y Pinnularia viridis en temperaturas de 22 a 55 °C. Tambien se registro una especie de la clase Chlorophyceae, Oedogonium sp., en temperaturas de 30 a 35 °C. Este manantial se caracteriza por presentar cambios drasticos de temperatura en trayectos cortos, que pueden ser de menos de 1 m, lo cual se observo reflejado en una distribucion heterogenea de las especies algales.