Population ecology of a critically endangered gecko, endemic to north-eastern of Argentina.

Homonota taragui is an endemic gecko of the northeast of Argentina. We estimate demographic parameters: number of individuals by populations, sex and ontogenetic stage; sexual dimorphism; survival of this species; and describe the use of microhabitat and movement patterns. We measured 11 morphological variables, determined the sex and marked individually. We found bigger head width in males. Some factors contribute to the vulnerability of this species such as its constrained geographical distribution, use of the specific microhabitat and the isolation of their populations. We highlight demography studies as an essential data source for management and conservation of critically endangered species.

The isolated rocky outcrops of northeastern Argentina and their role on the herpetofauna conservation.

Isolated rocky outcrops represent biodiversity centers, refuges for endangered species, and favorable scenarios for endemism. Most studies in these ecosystems have been focused mainly on their flora and secondarily on different groups of animals. To highlight the value of rocky outcrops as ecosystems for biodiversity conservation, in the present study, we describe the diversity of herptiles of three isolated rocky outcrops of northeastern Argentina and compare it with that of other natural areas of the region. We conducted fieldwork from September 2010 to March 2017. We calculated the alpha diversity and the number of rare, threatened and endemic species. For comparative diversity analysis, we calculated the importance of each area for amphibians and reptiles and the beta diversity. Were recorded a total of 56 species (23 amphibians and 33 reptiles), representing 35% of the herptiles recorded for Corrientes province. These species included 19 rare species, seven threatened species, and two endemic species. The overall beta diversity showed considerably differences in species composition between the compared areas. The rocky outcrops showed higher importance for amphibians and reptiles than the other areas studied. Our study contributes to the knowledge of rocky outcrops and highlights their importance in biodiversity conservation.

Bat (Mammalia: Chiroptera) biodiversity in a subtropical inselberg ecosystem of Northeastern Argentina / Biodiversidad de murciélagos (Mammalia: Chiroptera) en un ecosistema inselberg subtropical del Noreste de Argentina

Abstract Introduction: Rocky outcrops influence both micro and macro habitat for plants and animals by increasing the availability and predictability of food, providing shelter, and unique microclimatic conditions. Objective: We describe the bat assemblage in three isolated rocky outcrops and their surrounding pediments, adding new data about trophic guilds and roosts. Methods: We surveyed the bat fauna of Paraje Tres Cerros, Corrientes Province, Argentina, exploring 13 sites during 26 field trips, using mist nets and search of roosts. We made an accumulation species curve and calculate inventory completeness. The similarity and composition of different habitats was compared by a Non-Metric Multidimensional Scaling (NMDS) and an ANOSIM test. Results: We reported 13 species, with a completeness inventory of the 80 % (Jacknife1), corresponding to the families Vespertilionidae, Molossidae and Phyllostomidae. The insectivorous bats were the best represented guild. We found nine types of roost for eight species in different sites. The analysis expressed low differences in the species composition between both types of habitats in the area. Conclusions: The rocky outcrops and their pediments are important ecosystems for the conservation and diversity of the bats in the region, since their assemblages are regionally unique.

Resumen Introducción: Los afloramientos rocosos influyen tanto en el micro como en el macro hábitat de plantas y animales al incrementar la disponibilidad de alimentos, proporcionar refugios y brindar condiciones microclimáticas únicas. Objetivo: Describir el ensamble de murciélagos en tres afloramientos rocosos aislados y sus pendientes circundantes, incorporando nuevos datos sobre gremios tróficos y refugios. Métodos: Muestreamos la fauna de murciélagos del Paraje Tres Cerros, provincia de Corrientes, Argentina, exploramos 13 sitios durante 26 viajes de campo, usando redes de niebla y búsqueda de refugios. Realizamos una curva de acumulación de especies y calculamos la completitud del inventario. La similitud y composición de diferentes hábitats se comparó mediante un escalado multidimensional no métrico (NMDS) y una prueba ANOSIM. Resultados: Reportamos 13 especies, con una completitud del 80 % del inventario (Jacknife1), correspondientes a las familias Vespertilionidae, Molossidae y Phyllostomidae. Los gremios mejor representados fueron los insectívoros. Encontramos nueve tipos de refugios para ocho especies en diferentes sitios. Los análisis expresaron bajas diferencias en la composición de especies entre ambos tipos de hábitats en el área. Conclusión: Los afloramientos rocosos y pendientes son ecosistemas importantes para la conservación y diversidad de los murciélagos en la región, ya que sus comunidades son regionalmente únicas.

Role of lithology in the presence of natural radioactivity in drinking water samples from Tarragona province.

One hundred and ninety-six drinking water samples from the different regions of Tarragona province (Catalonia, Spain) were analysed to determine the gross alpha and beta activity. Individual alpha emitting isotope activities were also determined to evaluate a possible relationship between their radiological content and the lithological and hydrogeological formations present in the studied area. The results obtained showed that approximately 23% of the analysed samples, mainly from five of the evaluated regions, had a gross alpha index exceeding the parametric value of 0.1 Bq/L for waters intended for human consumption according to the current legislation. This could be related to the presence of natural radionuclides in these water samples. The differences between the radiological content in these samples could be related to the different lithological conditions of the areas included in this study. High activity levels of 234U, 238U, 224Ra, 226Ra and 228Ra were detected in specific samples, mainly from granitic and carbonate areas. This research also focuses on evaluating the radiological risk associated with water ingestion. In this regard, consuming 95.5% of the drinking water samples analysed would not imply a health risk to the population as the annual effective doses calculated were below 0.1 mSv/year. There was only one sample that exceeded this level with a value of 0.33 mSv/year. 226Ra activity concentration was the radionuclide that mainly contributed to this dose.

Comparative cytogenetic analysis in Erythrolamprus snakes (Serpentes: Dipsadidae) from Argentina.

We described the karyotypes of five snake taxa from Argentina: Erythrolamprus almadensis, E. ceii, E. poecilogyrus caesius, E. p. schotti and E. p. sublineatus, and also intergrading individuals between the last two subspecies by conventional staining, chromosome bandings and fluorescent in situ hybridization (FISH) with 28S ribosomal DNA probes. Erythrolamprus ceii and E. almadensis share a diploid chromosome number of 2n= 28, whereas in E. poecilogyrus intraspecific variations were observed: E. p. caesius has 2n= 28, E. p. schotti and E. p. sublineatus as well as in the intergrading individuals have 2n= 32. In E. almadensis and E. p. caesius, the 2nd and 6th chromosome pairs respectively are heteromorphic by size, morphology and C-banding pattern. These results allow us to suggest that these chromosome pairs might be considered as the ZW sex chromosomes in these species. The present comparative cytogenetic analyzes contributes to the already remarkable karyotypic variability in Erythrolamprus genus and propose a hypothesis about potential mechanisms involved in the chromosome evolution among taxa analyzed. Furthermore, the karyotypic differences observed between E. p. caesius (2n= 28) and E. p. schotti and E. p. sublineatus (2n= 32) might play a causal role in speciation.

Comunidades de aves de bosques y pastizales en los afloramientos rocosos aislados del Paraje Tres Cerros, Corrientes, Argentina / Bird communities of forests and grasslands on isolated rocky outcrops in Paraje Tres Cerros, Corrientes, Argentina

ResumenLos afloramientos rocosos aislados se describen como paisajes destacados en biodiversidad debido a la gran variedad de microhabitats, presencia de taxones restringidos y al alto recambio de especies con la matriz circundante. Particularmente los afloramientos rocosos aislados del Paraje Tres Cerros (ARPTC), Corrientes, Argentina, representan un paisaje único en la región, biológicamente fueron poco explorados. Se estudió la comunidad de aves de bosques y pastizales de los ARPTC mediante 136 listas de Mackinnon de diez especies durante la temporada reproductiva y no reproductiva. Se evaluó la diversidad, riqueza estimada y completitud de inventarios, abundancia de gremios tróficos y fenología de las especies. Se comparó estos atributos entre los bosques y pastizales. Se registraron 107 especies donde el bosque es 1.3 veces más diverso que el pastizal. La completitud de inventarios varió de 83 a 90 % en el pastizal y de 88 a 99 % en el bosque. Los hábitats se complementaron en un 62 % indicando una elevada ocurrencia de especies exclusivas. Las aves insectívoras fueron abundantes en ambos ambientes, mientras que las frugívoras en bosques y las granívoras en pastizales. Ambos hábitats son significativamente más ricos en especies en la estación reproductiva por la llegada de los migrantes estivales. Los resultados concuerdan con los patrones generales conocidos para las comunidades de aves y con otros específicos para las comunidades de aves de afloramientos rocosos. El presente estudio resalta la importancia de los afloramientos rocosos aislados de Paraje Tres Cerros para la protección de la biodiversidad de aves a nivel local y regional y representa una herramienta de manejo para la conservación de estos ecosistemas.

AbstractIsolated rocky outcrops can act as patch habitats that host great biodiversity through the diversity of microhabitats, presence of restricted taxa and the high turnover of species in the patch matrix. The isolated rocky outcrops of Paraje Tres Cerros (ARPTC), Corrientes, Argentina, are a unique landscape in the region and biologically little explored. We conducted a study to describe for the first time the bird community of the forest and grassland of the ARPTC, using 136 lists following the ten species Mackinnon method from the breeding and non-breeding seasons. We evaluated the diversity, trophic guilds and phenology of the species, and compared attributes of grassland and forest communities. The total species richness was 107, with the forest being 1.3 times more diverse than the grassland. Completeness of inventories ranged from 83-90 % in the grassland and 88 to 99 % in the forest. The habitat complementarity was 62 %, indicating the presence of several species exclusive of forest and grassland habitats. The trophic structure of communities showed a good representation of insectivorous birds in both habitats. Frugivorous birds were more frequent in the forest and granivorous birds were more frequent in the grasslands. Due to the arrival of migrant species, both habitats had significantly higher richness in the breeding season than in the non-breeding season. Our results showed similar general aspects and patterns for bird communities and with specific studies for bird communities of rocky outcrops. The present study highlights the importance of the isolated rocky outcrops of Paraje Tres Cerros for the protection of local and regional bird biodiversity and represents a benchmark for the management and the protection of these ecosystems.

Diethylstilbestrol exposure in neonatal mice induces changes in the adulthood in the immune response to taenia crassiceps without modifications of parasite loads.

Industrial growth has increased the exposition to endocrine disruptor compounds (EDC's), which are exogenous agents with agonist or antagonist action of endogenous steroid hormones that may affect the course of parasite infections. We wanted to determine if the exposure to diethylstilbestrol (DES), an estrogen agonist, to both male and female mice affected the immune response and their susceptibility to T. crassiceps cysticercosis. In all infected groups, females showed higher parasite loads than males, and neonatal DES administration did not modify this pattern. In the spleen, noninfected mice showed sex-related differences in the percentage of the CD8+ subpopulation, but DES decreased the percentage of CD3+, CD19+, and CD8+ subpopulations in infected mice. In the mesenteric lymphatic node (MNL), DES showed a dimorphic effect in the percentage of CD19+ cells. Regarding estrogen receptor alpha (ER-α) expression, DES treatment induced a reduction in the expression of this receptor in both noninfected female and male mice in the spleen, which was decreased only in males in CD3+ and CD8+ lymphocytes in MNL cell subpopulations. Our study is the first one to demonstrate that DES neonatal treatment in male and female mice affects the immune cell percentage, without effect on the susceptibility to T. crassiceps cysticercosis.

The karyotype of Adenomera diptyx (Boettger 1885) (Anura, Leptodactylidae) from northeastern Argentina.

In this work we analyzed the karyotype of five populations of Adenomera diptyx from Argentina after conventional staining, Ag-NOR and C-banding. All specimens presented 2n = 26 and FN = 34. The karyotype was formed by three submetacentric, one metacentric and nine telocentric pairs. Silver staining revealed that the NOR was located on a secondary constriction in pair 7. C- banding evidenced constitutive heterochromatin at the pericentromeric region of all chromosomes. The karyotype of A. diptyx was similar to that of A. hylaedactyla (2n = 26, FN = 34) and different from that of A. andreae (2n = 26, FN = 40) in the fundamental number and secondary constriction position. It also differed from the karyotypes of A. marmorata (2n = 24, FN = 34 and 36) and of A. aff. bokermanni (2n = 23, FN = 34) in diploid number. Until a comprehensive cytogenetic analysis of all the species of the genus is performed, their chromosome evolution will remain poorly understood.

The karyotype of Adenomera diptyx (Boettger 1885) (Anura, Leptodactylidae) from northeastern Argentina

In this work we analyzed the karyotype of five populations of Adenomera diptyx from Argentina after conventional staining, Ag-NOR and C-banding. All specimens presented 2n = 26 and FN = 34. The karyotype was formed by three submetacentric, one metacentric and nine telocentric pairs. Silver staining revealed that the NOR was located on a secondary constriction in pair 7. C- banding evidenced constitutive heterochromatin at the pericentromeric region of all chromosomes. The karyotype of A. diptyx was similar to that of A. hylaedactyla (2n = 26, FN = 34) and different from that of A. andreae (2n = 26, FN = 40) in the fundamental number and secondary constriction position. It also differed from the karyotypes of A. marmorata (2n = 24, FN = 34 and 36) and of A. aff. bokermanni (2n = 23, FN = 34) in diploid number. Until a comprehensive cytogenetic analysis of all the species of the genus is performed, their chromosome evolution will remain poorly understood.