Primer registro de leucismo en el género Coendou Lacépède, 1799 (Rodentia: Erethizontidae)

A case of leucism is reported for the first time in the species Coendou prehensilis. The individual was found by chance in an area of disturbed forest in the Andes region of Venezuela.Se reporta por primera vez un caso de leucismo en la especie Coendou prehensilis. El individuo fue hallado de forma fortuita en una zona de bosque perturbado en la región de Los Andes en Venezuela

Ganglion-specific splicing of TRPV1 underlies infrared sensation in vampire bats.

Vampire bats (Desmodus rotundus) are obligate blood feeders that have evolved specialized systems to suit their sanguinary lifestyle. Chief among such adaptations is the ability to detect infrared radiation as a means of locating hotspots on warm-blooded prey. Among vertebrates, only vampire bats, boas, pythons and pit vipers are capable of detecting infrared radiation. In each case, infrared signals are detected by trigeminal nerve fibres that innervate specialized pit organs on the animal's face. Thus, vampire bats and snakes have taken thermosensation to the extreme by developing specialized systems for detecting infrared radiation. As such, these creatures provide a window into the molecular and genetic mechanisms underlying evolutionary tuning of thermoreceptors in a species-specific or cell-type-specific manner. Previously, we have shown that snakes co-opt a non-heat-sensitive channel, vertebrate TRPA1 (transient receptor potential cation channel A1), to produce an infrared detector. Here we show that vampire bats tune a channel that is already heat-sensitive, TRPV1, by lowering its thermal activation threshold to about 30 °C. This is achieved through alternative splicing of TRPV1 transcripts to produce a channel with a truncated carboxy-terminal cytoplasmic domain. These splicing events occur exclusively in trigeminal ganglia, and not in dorsal root ganglia, thereby maintaining a role for TRPV1 as a detector of noxious heat in somatic afferents. This reflects a unique organization of the bat Trpv1 gene that we show to be characteristic of Laurasiatheria mammals (cows, dogs and moles), supporting a close phylogenetic relationship with bats. These findings reveal a novel molecular mechanism for physiological tuning of thermosensory nerve fibres

CURRENT DISTRIBUTION, HABITAT USE, AND BREEDING RECORDS OF THE HOUSE SPARROW (PASSER DOMESTICUS) IN VENEZUELA

ABSTRACT ∙ The House Sparrow (Passer domesticus, Passeridae), native to Eurasia and northern Africa, was introduced to the Americas and Australia where it inhabits mainly urban environments. The objective of this study was to determine the distribution of the House Sparrow in Venezuela from our own observations and data reported in personal communications, published material, and eBird records. House Sparrows were recorded for first time in Venezuela in 1996 at the port of La Guaira. Since then, records have increased, and we found 133 records of the House Sparrow until July 2015, in the states of Falcón, Zulia, Vargas, Miranda, Carabobo, Anzoátegui, and Los Roques Archipelago. The states of Falcón and Vargas included the greatest number of records, and 2015 was the year with the most records. Most sightings occurred in urban areas of coastal Venezuela. House Sparrows were recorded within three protected areas: Refugio de Fauna Silvestre de Cuare (Falcón), Refugio de Fauna Silvestre y Reserva de Pesca Ciénaga de los Olivitos (Zulia), and Parque Nacional Archipiélago Los Roques. Two records for Caracas, one for Barquisimeto and another for Margarita Island, need confirmation. Breeding was confirmed in five states where the House Sparrow is currently present, and records indicated that the nesting season extends from February to November. Most nests (84%) were located in man‐made structures, but two breeding records included a nesting colony in cavities of an exotic palm (Phoenix sp.) in Falcón and a nest under a pile of dead coral fragments in Los Roques Archipelago. We found evidence of foraging on new food items from two coastal trees (Conocarpus erectus and Coccoloba uvifera). Formal research and long‐term surveys are required to assess the functional ecological role of this exotic species in the avian communities of Venezuela.  RESUMEN ∙ Distribución actual, uso de hábitat y registros reproductivos del Gorrión Común (Passer domesticus) en Venezuela El Gorrión Común (Passer domesticus, Passeridae), nativo de Eurasia y el norte de África, fue introducido en gran parte de América y Australia, donde ocupa principalmente hábitats urbanos. El objetivo de este trabajo consistió en determinar la distribución del Gorrión Común en Venezuela con base en nuestras observaciones y datos reportados en comunicaciones personales, material publicado y registros en eBird. Los Gorriones Comunes se registraron por primera vez en Venezuela en 1996 en el puerto de La Guaira. Desde entonces, el número de registros se ha incrementado y nosotros encontramos 133 registros de Gorrión Común fechados hasta el julio de 2015 para los estados Falcón, Zulia, Vargas, Miranda, Carabobo, Anzoátegui y el Archipiélago de Los Roques. Los estados con mayor número de registros fueron Falcón y Vargas, y el año con el mayor número de registros fue 2015. La mayor parte de los avistamientos se realizaron dentro de áreas urbanas en la costa de Venezuela. Se registraron gorriones en tres áreas protegidas: el Refugio de Fauna Silvestre de Cuare (Falcón), el Refugio de Fauna Silvestre y Reserva de Pesca Ciénaga de los Olivitos (Zulia) y el Parque Nacional Archipiélago Los Roques. Dos reportes de avistamientos para Caracas, uno para Barquisimeto y otro para la Isla de Margarita requieren confirmación. La reproducción fue confirmada en cinco de los estados donde el Gorrión Común está presente actualmente, y los registros indican que la época reproductiva se extiende de febrero a noviembre. La mayoría de los nidos (84%) se ubicaron en estructuras hechas por el hombre, pero dos registros reproductivos incluyen una colonia de anidación en cavidades de una palma exótica (Phoenix sp.) en Falcón, y un nido bajo una pila de fragmentos de coral muerto en el Archipiélago de Los Roques. Encontramos nueva evidencia de alimentación con ítems de dos árboles costeros (Conocarpus erectus y Coccoloba uvifera). Estudios formales y monitoreo a largo plazo son necesarios para evaluar el rol ecológico funcional de esta especie exótica en las comunidades de aves en Venezuela

MORFOLOGÍA COMPARATIVA DE EJEMPLARES DE ASTYANAX BIMACULATVS (CHARACIFORMES, CHARACIDAE) DE LAS CUENCAS DEL RIO ORINOCO Y DEL CARIBE (RÍOS UÑARE, MANZANARES Y LA TOMA), VENEZUELA

Se caracterizaron los patrones morfométricos de varias poblaciones de Astyanax bimaculatus provenientes de diferentes localidades de las cuencas del Río Orinoco y del Caribe mediante el método de las cerchas. Adicionalmente se determinaron 3 variables merísticas que permitieron separar distintos morfotipos de la especie en Venezuela. Los resultados del análisis univariado de los caracteres merísticos seleccionados y el análisis de componentes principales de la matriz de covarianza de los logaritmos de los datos, evidenciaron diferencias merísticas y moribmétricas entre ejemplares, comprobándose la existencia de al menos dos morfotipos bien diferenciados. Los ejemplares de los ríos Orituco. Tamanaco y Arenas no presentan dimorfismo sexual, mientras las muestras de los ríos La Toma y Gücre (Morfotipo A), sí lo presentan. Se evidencio que existen variaciones morfológicas ente los ejemplares de A. bimaculatus de las cuatro cuencas del estudio. La subcuenca del Rio Güere conforma una zona por demás interesante pues en ella coexisten simpátricamente representantes de dos morfotipos. Hxiste evidencia de que esta simpatría puede ser el resultado de introducciones desde el Orinoco realizadas en los años 70. Los complejos patrones de variación morfológica encontradas en esta especie, tanto dentro de las localidades de cada cuenca, como intracuencas. señala las dificultades que se presentan en la correcta interpretación de la historia evolutiva de la ictiofauna venezolana, donde no solo hay que considerar el concurso de diferentes procesos de diferenciación ecológica y biológica, sino también el posible trasplante indiscriminado de especies entre cuencas, sin consideración por los posibles procesos históricos y geográficos del país

Ganglion-specific splicing of TRPV1 underlies infrared sensation in vampire bats.

Vampire bats (Desmodus rotundus) are obligate blood feeders that have evolved specialized systems to suit their sanguinary lifestyle. Chief among such adaptations is the ability to detect infrared radiation as a means of locating hotspots on warm-blooded prey. Among vertebrates, only vampire bats, boas, pythons and pit vipers are capable of detecting infrared radiation. In each case, infrared signals are detected by trigeminal nerve fibres that innervate specialized pit organs on the animal's face. Thus, vampire bats and snakes have taken thermosensation to the extreme by developing specialized systems for detecting infrared radiation. As such, these creatures provide a window into the molecular and genetic mechanisms underlying evolutionary tuning of thermoreceptors in a species-specific or cell-type-specific manner. Previously, we have shown that snakes co-opt a non-heat-sensitive channel, vertebrate TRPA1 (transient receptor potential cation channel A1), to produce an infrared detector. Here we show that vampire bats tune a channel that is already heat-sensitive, TRPV1, by lowering its thermal activation threshold to about 30 °C. This is achieved through alternative splicing of TRPV1 transcripts to produce a channel with a truncated carboxy-terminal cytoplasmic domain. These splicing events occur exclusively in trigeminal ganglia, and not in dorsal root ganglia, thereby maintaining a role for TRPV1 as a detector of noxious heat in somatic afferents. This reflects a unique organization of the bat Trpv1 gene that we show to be characteristic of Laurasiatheria mammals (cows, dogs and moles), supporting a close phylogenetic relationship with bats. These findings reveal a novel molecular mechanism for physiological tuning of thermosensory nerve fibres

Phyllostomid bat occurence in successional stages of neotropical dry forests

Tropical dry forests (TDFs) are highly endangered tropical ecosystems being replaced by a complex mosaic of patches of different successional stages, agricultural fields and pasturelands. In this context, it is urgent to understand how taxa playing critical ecosystem roles respond to habitat modification. Because Phyllostomid bats provide important ecosystem services (e.g. facilitate gene flow among plant populations and promote forest regeneration), in this study we aimed to identify potential patterns on their response to TDF transformation in sites representing four different successional stages (initial, early, intermediate and late) in three Neotropical regions: México, Venezuela and Brazil. We evaluated bat occurrence at the species, ensemble (abundance) and assemblage level (species richness and composition, guild composition). We also evaluated how bat occurrence was modulated by the marked seasonality of TDFs. In general, we found high seasonal and regional specificities in phyllostomid occurrence, driven by specificities at species and guild levels. For example, highest frugivore abundance occurred in the early stage of the moistest TDF, while highest nectarivore abundance occurred in the same stage of the driest TDF. The high regional specificity of phyllostomid responses could arise from: (1) the distinctive environmental conditions of each region, (2) the specific behavior and ecological requirements of the regional bat species, (3) the composition, structure and phenological patterns of plant assemblages in the different stages, and (4) the regional landscape composition and configuration. We conclude that, in tropical seasonal environments, it is imperative to perform long-term studies considering seasonal variations in environmental conditions and plant phenology, as well as the role of landscape attributes. This approach will allow us to identify potential patterns in bat responses to habitat modification, which constitute an invaluable tool for not only bat biodiversity conservation but also for the conservation of the key ecological processes they provide

Species richness estimated with the first-order jackknife estimator, per site and per season.

<p>Study regions: Chamela Cuixmala Biosphere Reserve in Mexico (A), Unidad de Producción Socialista Agropecuaria Piñero in Venezuela (B), and Mata Seca State Park in Brazil (C). Sampling sites representing different successional stages are: pastures (from P1 to P3), early (from E1 to E3), intermediate (from I1 to I3) and late stage (from L1 to L3). Seasons: rainy season (triangles) and dry season (circles). Error bars represent the ±95% confidence intervals.</p

Percentage of variation in the population, ensemble and assemblage-level parameters associated with the variation of the explanatory variable.

<p>Study sites are the same as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0084572#pone-0084572-g001" target="_blank">Fig. 1</a>. Seasons: rainy season (RS), and dry season (DS). Parameters at population-level: capture rate (individuals/night) as an indicator of local abundance of the species. Parameters at ensemble-level: capture rate (individuals/night) as an indicator of local abundance of the guild. Parameters at assemblage-level: scores of the first and second ordination axis reflecting assemblages’ dissimilarities in species composition (Species SC₁ and Species SC₂, respectively); scores of the second ordination axis reflecting assemblages’ dissimilarities in guild composition (Guild SC₂), and species richness estimated by using the first-order jackknife estimator (Jack1). Explanatory variables: successional stage (S_stage) and scores of the first ordination axis reflecting sampling sites’ dissimilarities in vegetation structural complexity (V_struct). n: number of sampling sites. <i>R²_dev</i> is the fraction of the total deviance explained by a model considering all explanatory variables when the Poisson error distribution was used and <i>R²</i> when the normal error distribution was used. Significant relationships according to the randomization test appear in bold. Negative relationships are shown in parentheses. Only the parameters that were significantly associated with some explanatory variable are shown in this table. See <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0084572#pone.0084572.s005" target="_blank">Table S3</a> for all the results.</p