Abstract The remarkable sexual dimorphism, characteristic of the family Gonyleptidae (Opiliones), as well as the occurrence of discrete morphotypes in males with respect to body size and weaponry, have merited several analyses, by several authors, using linear morphometrics. In this work, we propose the application of geometric morphometrics techniques to analyze the morphometric variability in centroid size and shape of dorsal scutum and coxa IV of males of the Discocyrtus prospicuus complex (Gonyleptidae), in order to evaluate the existence of discrete morphotypes and the influence of the geographic factor on morphometric variability. Likewise, it is aimed to characterize the sexual dimorphism based on the same characters. One hundred-thirteen individuals (58 males and 55 females), from 11 localities in 3 Argentine provinces, were analyzed. Results show that sexual dimorphism affects both the size and the conformation of the 2 measured structures, although in a different direction in coxae and dorsal scutum. Meanwhile, males showed 2 separate subgroups with respect to the centroid size of coxae and scutum, although with slight differences depending on geographic origin. The occurrence of subgroups related to centroid size is also described for the first time for females. These results constitute an advance in the understanding of the occurrence of dimorphisms and the geographic variations associated with this variation.

Resumen El notable dimorfismo sexual característico de la familia Gonyleptidae (Opiliones), así como la existencia de morfotipos discretos en machos respecto del tamaño corporal y la armadura, han merecido diversos análisis por varios autores, utilizando morfometría lineal. En este trabajo se propone la aplicación de técnicas de morfometría geométrica para analizar la variabilidad en tamaño centroide y conformación del escudo dorsal y coxa IV de machos del complejo Discocyrtus prospicuus (Gonyleptidae), a fin de evaluar la existencia de morfotipos discretos y la influencia del factor geográfico sobre dicha variabilidad. Asimismo, se apunta a caracterizar el dimorfismo sexual con base en los mismos caracteres. Se analizaron 113 individuos (58 machos y 55 hembras), provenientes de 11 localidades de 3 provincias argentinas. Los resultados muestran que el dimorfismo sexual afecta tanto al tamaño como la conformación de las 2 estructuras medidas (coxas IV y escudo dorsal), aunque ocurriendo en distinto sentido. Por su parte, los machos evidenciaron 2 subgrupos separados en cuanto a tamaño centroide de coxas y escudo, aunque con leves diferencias según el origen geográfico. Se describe por primera vez la existencia de subgrupos relacionados a tamaño centroide también para hembras. Estos resultados constituyen un avance en la comprensión de la ocurrencia de dimorfismos y las variaciones geográficas asociadas con esta variación.

Abstract: Arsenic (As) contaminated drinking water is a well-known problem that still affects millions of people worldwide. Therefore, biomonitoring studies of human populations exposed to arsenic via drinking water along with the search for new biomarkers become important. Huautla, Morelos, Mexico, is a mining district where 780 000 tons of toxic wastes have been discharged at 500 m from Huautla town, where the main contaminants are Pb and As and still, there is no information about their effect on the human population health. Therefore, the aims of this study were: A) To examine As concentration in drinking water and in whole blood samples from the individuals residing in Huautla, Morelos, B) To evaluate DNA damage levels in whole blood lymphocytes from the exposed individuals and C) To evaluate if there is a correlation between DNA damage and total As blood levels from the exposed individuals. Our results demonstrate that drinking water from Huautla, Morelos, is contaminated with As (0.240 ± 0.008 μg/ml) exceeding the national (0.025 μg/ml) and international standards (0.010 μg/ml). Total As levels in whole blood samples from the exposed individuals corroborate this exposure (60 ± 9 μg/l). As stimulated positively the lymphocyte cell cycle and induced DNA breaks and chromosome aberrations (CA), which were positively and significantly correlated with As concentrations in whole blood samples. Among the types of CA analyzed, terminal deletions registered the highest determination coefficient (R2 = 0.70). We provide evidence that supports the use of total As blood concentration as an internal biomarker of exposure in human populations. A fact that might be of particular interest in subjects with kidney related conditions, in which the normalization of total As/gr creatinine in urine may not reflect accurately the exposure level to this metalloid.

Resumen: La contaminación por arsénico (As) en el agua es un problema conocido que sigue afectando a millones de personas en el mundo. Por lo que, el biomonitoreo de poblaciones humanas expuestas a As a través del agua destinada al consumo humano en conjunto con la búsqueda de nuevos biomarcadores es fundamental. Huautla, Morelos, México, fue un distrito minero, en el cual existen 780 000 ton de residuos mineros localizados a 500 m de la población y en donde los principales contaminantes son el Pb y el As y aún no hay información relacionada a sus efectos sobre la salud de la población. Los objetivos del presente trabajo fueron: A) Examinar las concentraciones del As en el agua y en muestras de sangre entera de individuos de la población de Huautla, Morelos, B) Evaluar los niveles de daño al ADN en linfocitos de sangre periférica de la población expuesta y C) Evaluar si existe una correlación entre los niveles de daño al ADN y la concentración de As en sangre de los individuos expuestos. Los resultados obtenidos demuestran que el agua para beber de la localidad de Huautla está contaminada por As (0.240 ± 0.008 μg/ml) excediendo las normas nacionales (0.025 μg/ml) e internacionales (0.010 μg/ml). La concentración de As en las muestras de sangre entera de los individuos expuestos corrobora la exposición (60 ± 9 μg/L). El As afectó el ciclo celular e indujo rompimientos en el ADN, así como aberraciones cromosómicas (AC), las cuales se correlacionaron positiva y significativamente con la concentración de As en sangre. Entre las AC analizadas, las deleciones terminales fueron las que registraron el coeficiente de determinación más alto (R2 = 0.70). Este trabajo provee evidencia que apoya el uso de la concentración total de As en sangre como biomarcador de exposición interna en poblaciones humanas. Lo que resulta importante en particular en individuos con enfermedades relacionadas con disfunción renal en los cuales la normalización de As/gr creatinina en orina puede no reflejar correctamente el nivel de exposición al metaloide.

Abstract: INTRODUCTION : Insects of the subfamily Triatominae are vectors of Trypanosoma cruzi , the Chagas disease parasite, and their flying behavior has epidemiological importance. The flying capacity is strikingly different across and within Triatominae species, as well as between sexes or individuals. Many Triatoma infestans individuals have wings but no flying muscles. In other Triatominae species, no clear relationships were found between wing length and flying behavior. If wing presence or size is not reflective of the flying behavior, which other parts of the body could be considered as reliable markers of this important function? METHODS : The genus Mepraia has exceptional characteristics with invariably wingless females and wingless or winged males. We calculated the porous surface exposed to odorant molecules to estimate the olfactory capacity of Mepraia spinolai . The head shape and thorax size were estimated using the geometric morphometric approach and traditional morphometric techniques, respectively. RESULTS : Alary polymorphism in M. spinolai was significantly associated with consistent modification of the thorax size, head shape, and notable change in the estimated olfactory capacity. The macropterous individuals had a larger olfactory surface and thorax size and significantly different head shape compared to those of the micropterous individuals. CONCLUSIONS: We concluded that these structural changes could be associated with the flying potential of Triatominae. Thus, morphological attributes not found on wings could help determine the likely flying potential of the bugs.

The presence of Triatoma infestans in habitats treated with insecticides constitutes a frequent problem in endemic areas. Basing our study on the hypothesis that descendants of a residual population should be more similar to the pre-treatment population than to any other, we compared the indications of two quantitative morphological approaches. This study seeks to find the origin of 247 T. infestans from three populations found in two chicken coops and a goat corral after treatment with insecticides. The results obtained by quantitative morphology suggest that the T. infestans found between three-34 months after the application of insecticides formed mixed populations with insects derived from residual foci and neighbouring habitats. Our analyses also showed the presence of a phenotype which does not resemble neither the pre-treatment phenotype nor the one from neighbouring populations, suggesting the presence of a particular post-treatment phenotype. The heads size showed some variations in males from different populations and remained unchanged in females, which reinforces the hypothesis of an intraspecific competition for food with priority for females. This article presents, for the first time, the combined analysis of geometric morphometry of heads and antennal phenotypes to identify the composition of reinfesting populations.