70 research outputs found

    Sceloporus smithi Hartweg and Oliver, 1937 (Squamata: Phrynosomatidae): distributional range extension and a new elevation record from Oaxaca, México

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    A male Sceloporus smithi was collected at Hierve El Agua, in the Municipality of San Lorenzo Albarradas, Oaxaca, México. This record extends the known distribution of the species by approximately 25 km N from the closest acknowledged locality and also represents a new upward elevational record. Even though the elevation at this site is almost 700 m higher than for previously documented localities, the subhumid forest and igneous rock association is similar to other inhabited localities at lower elevations

    Primer registro de <i>Sceloporus serrifer</i> Cope 1866, (Squamata: Phrynosomatidae) para Quintana Roo, México

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    Se reporta por primera vez para el estado de Quintana Roo la presencia de la lagartija Sceloporus serrifer. Este hallazgo es importante ya que extiende el rango de distribución a 217 km de la localidad más cercana y amplia el rango de distribución de la especie dentro de la península de Yucatán, además, aumenta el número de especies de saurios presentes en este estado.Asociación Herpetológica Argentina (AHA

    Diversity of Copestylum Macquart, 1846 (Diptera, Syrphidae) associated to decaying cacti (Cactaceae Juss, 1789) in two Biosphere Reserves from central Mexico

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    El conocimiento de la biodiversidad de los sírfidos (Diptera: Syrphidae) en las zonas semiáridas de México, es muy limitado, sobre todo, al relacionado con las cactáceas en descomposición. Este estudio aporta un inventario faunístico de los sírfidos del género Copestylum asociados a los tejidos en descomposición de los cactus de matorrales crasicaules en dos Reservas de la Biosfera, “Barranca de Metztitlán” (RBBM) y “Tehuacán-Cuicatlán” (RBTC), ambas situadas en el centro de México. Se analiza la diversidad y composición de especies de sírfidos en ambas reservas y se documenta la especie de cactus a la que se asocian las larvas de estos dípteros durante la época de lluvias. El método de recolecta fue mediante búsqueda directa de estados inmaduros que se desarrollan en tejidos de cactáceas en descomposición. Se obtuvieron 137 ejemplares de sírfidos pertenecientes a 10 especies entre las dos reservas estudiadas. Los resultados indican que no existen diferencias significativas en la riqueza de especies entre ambas reservas, pero sí hay diferencia al comparar la diversidad de orden q2. En la RBBM, la especie dominante fue Copestylum latum, mientras que Copestylum posticum fue la especie dominante en la RBTC. La especie de cactus determina la segregación de sírfidos en cada reserva. En la RBBM, las especies de sírfidos se asociaron a las especies de cactus Isolatocereus dumortieri y Myrtillocactus geometrizans, mientras que, en la RBTC fueron Neobuxbaumia mezcalensis, Pachycereus hollianus y Myrtillocactus geometrizans.Biodiversity knowledge of syrphids (Diptera: Syrphidae) from the semiarid environments of Mexico is still limited; particularly, those associated to the decaying cactus. In this study, we provide an inventory of the syrphid species from two Biosphere Reserves in the semiarid zones of central Mexico. We compare the diversity and species composition of syrphids through both Biosphere Reserves and we documented the host cactus species of syrphids during the rainy season. Larvae were sampled by hand searching on decayed cacti tissues. We recorded a total of 137 individuals of syrphids and 10 species between the two studied Biosphere Reserves. Our results revealed that there are not significant differences in species richness between RBBM and RBTC but there were significant differences in species diversity of order q2. We found that Copestylum latum was the dominant syrphid at RBBM whereas Copestylum posticum was dominant across the RBTC. The cactus species is presumably determining the species segregation of syrphids. In the RBBM, syrphid were associated to the cacti Isolatocereus dumortieri and Myrtillocactus geometrizans; meanwhile, in the RBTC syrphids were associated to Neobuxbaumia mezcalensis, Pachycereus hollianus and Myrtillocactus geometrizans

    Primer registro de <i>Sceloporus serrifer</i> Cope 1866, (Squamata: Phrynosomatidae) para Quintana Roo, México

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    Se reporta por primera vez para el estado de Quintana Roo la presencia de la lagartija Sceloporus serrifer. Este hallazgo es importante ya que extiende el rango de distribución a 217 km de la localidad más cercana y amplia el rango de distribución de la especie dentro de la península de Yucatán, además, aumenta el número de especies de saurios presentes en este estado.Asociación Herpetológica Argentina (AHA

    Primer registro de <i>Sceloporus serrifer</i> Cope 1866, (Squamata: Phrynosomatidae) para Quintana Roo, México

    Get PDF
    Se reporta por primera vez para el estado de Quintana Roo la presencia de la lagartija Sceloporus serrifer. Este hallazgo es importante ya que extiende el rango de distribución a 217 km de la localidad más cercana y amplia el rango de distribución de la especie dentro de la península de Yucatán, además, aumenta el número de especies de saurios presentes en este estado.Asociación Herpetológica Argentina (AHA

    Effects of traditional agroecosystems and grazing areas on amphibian diversity in a region of central Mexico

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    Habitat loss or degradation due to land cover change is regarded as one of the main drivers of amphibian decline; therefore, it is imperative to assess the effects of land-cover change on this group of vertebrates. In this study, we analyze changes in alpha and beta diversity of amphibian communities found in five land-cover types: mountain cloud forest, tropical evergreen forest, shade coffee, milpa huasteca, and grazing areas; six samples sites were established for each land-cover type, separated at least one km away. The study was conducted in the northwest part of the state of Hidalgo, in a transition zone between the Sierra Madre Oriental and the Gulf of Mexico, which is a region rich in amphibian species. The results indicate that alpha diversity decreases with loss of canopy cover, this being high in mountain cloud forest, tropical evergreen forest, and Shade coffee, and low in milpa huasteca and grazing areas. The land-cover type with the highest species evenness was found in milpa huasteca and the lowest in. The highest beta diversity was observed among tropical evergreen forest and grazing areas. Mountain cloud forest contains both exclusive species and the highest number of species currently regarded as threatened by national and international conservation assessment systems. In order to preserve amphibian diversity in the study area it is vital to protect the last remnants of native vegetation, especially mountain cloud forest, but also including Shade coffee, since the latter habitat harbors amphibian diversity similar to that found in native forests. Finally, implementation of policies that both reduce Grazing areas and increase their productivity is also necessary, since these highly modified areas turn out to be the ones that affect amphibian diversity the most

    Xenosaurus newmanorum Taylor, 1949 (Squamata: Xenosauridae): Occurrence in the state of Hidalgo, Mexico

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    Herein we report 22 individuals of Xenosaurus newmanorum representing a new state record for Hidalgo, Mexico from the Municipality of Pisaflores. Previously, this species was known only from the Municipality of Xilitla in San Luis Potosí. These new records extend the distribution of this species 13.6 km south of its previously known occurrence. We also compare total body and tail lengths for the lizards in addition to cloacal temperatures and several measurements associated with microhabitat characteristics, which are equivalent at all three sites. That microhabitat congruence suggests that its preservation is critical for protecting X. newmanorum from population decline

    Quantitative trait locus mapping associated with earliness and fruit weight in tomato

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    The flowering time is regarded as an important factor that affects yield in various crops. In order to understand how the molecular basis controlling main components of earliness in tomato (Solanum lycopersicum L.), and to deduce whether the correlation between fruit weight, days to flowering and seed weight, is caused by pleiotropic effects or genetic linkage, a QTLs analysis was carried out using an F2 interspecific population derived from the cross of S. lycopersicum and S. pimpinellifolium. The analysis revealed that most of the components related to earliness were independent due to the absence of phenotypic correlation and lack of co-localization of their QTLs. QTLs affecting the flowering time showed considerable variation over time in values of explained phenotypic variation and average effects, which suggested dominance becomes more evident over time. The path analysis showed that traits such as days to flowering, seed weight, and length of the first leaf had a significant effect on the expression of fruit weight, confirming that their correlations were due to linkage. This result was also confirmed in two genomic regions located on chromosomes 1 and 4, where despite showing high co-localization of QTLs associated to days to flowering, seed weight and fruit weight, the presence and absence of epistasis in dfft1.1 × dftt4.1 and fw1.1 × fw4.1, suggested that the linkage was the main cause of the co-localization

    Why is the egg retention in oviparous species a step to viviparity?: an example with lizards

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    Se presenta una revisión sobre las hipótesis ecológicas y fisiológicas en la transición de la oviparidad a la viviparidad usando como grupo modelo a las lagartijas (Squamata). Además, se incluyen ejemplos de especies de lagartijas que prueban la retención de los huevos en el oviducto durante el desarrollo embrionario prolongado en altas latitudes y ambientes templados de montaña. Las hipótesis ecológica y fisiológica indican que el clima frío favorece la retención del huevo por tiempos prolongados y la disminución de glándulas calcáreas, favoreciendo el paso evolutivo a la viviparidad en este grupo de vertebrados. Actualmente, hace falta estudios con especies ovíparas que habitan ambientes templados de altas latitudes (climas fríos) y de ambientes templados de montañas que presentan retención de huevos en estadios avanzados.A review on the ecological and physiological hypotheses in the transition from oviparity to viviparity is presented using lizards (Squamata) as a model group. In addition, examples of lizard species are included that test the retention of eggs in the oviduct during prolonged embryonic development in high latitudes and temperate mountain environments. The ecological and physiological hypotheses indicate that the cold climate favors the retention of the egg for long periods of time and the decrease in calcareous glands, favoring the evolutionary passage to viviparity in this group of vertebrates. To date, studies are needed with oviparous species that inhabit temperate environments at high latitudes (cold climates) and temperate mountain environments that present egg retention in advanced stages

    Reproductive strategy of male and female eastern spiny lizards Sceloporus spinosus (Squamata: Phrynosomatidae) from a region of the Chihuahuan Desert, México

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    We examined the reproductive strategy of male (n = 84) and female (n = 62) S. spinosus from a single population in San Luis Potosí, México. The male reproductive cycle peaked in March and April and declined from May to September, and was not correlated with fat body mass, but was positively correlated with liver mass. The female reproductive cycle peaked in April and May and declined from June through November, and was not correlated with fat body mass, but was correlated with liver mass. Mean clutch size based on oviductal eggs was 17.5 ± 1.9 (n = 12), and was not correlated with female snout-vent length. Our results for S. spinosus are generally similar to those of other populations of the S. spinosus species group. However, there are differences in some traits (e.g., timing of the initiation of the female reproductive cycle; clutch size), suggesting that the S. spinosus group could serve as another model group within Sceloporus to explore ecological and evolutionary causes of among population life history variation
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