In the present investigation, four macrophytes, namely Typha latifolia (L.), Lemna minor (L.), Eichhornia crassipes (Mart.) Solms-Laubach, and Myriophyllum aquaticum (Vell.) Verdc, were evaluated for their heavy metal (Cu, Pb, Hg, and Zn) hyperaccumulation potential under laboratory conditions. Tolerance analyses were performed for 7 days of exposure at five different treatments of the metals mixture (Cu, Hg, Pb, and Zn). The production of chlorophyll and carotenoids was determined at the end of each treatment. L. minor revealed to be sensitive, because it did not survive in all the tested concentrations after 72 hours of exposure. E. crassipes and M. aquaticum displayed the highest tolerance to the metals mixture. For the most tolerant species of aquatic macrophytes, The removal kinetics of E. crassipes and M. aquaticum was carried out, using the following mixture of metals: Cu (0.5 mg/L) and Hg, Pb, and Zn 0.25 mg/L. The obtained results revealed that E. crassipes can remove 99.80% of Cu, 97.88% of Pb, 99.53% of Hg, and 94.37% of Zn. M. aquaticum withdraws 95.2% of Cu, 94.28% of Pb, 99.19% of Hg, and 91.91% of Zn. The obtained results suggest that these two species of macrophytes could be used for the phytoremediation of this mixture of heavy metals from the polluted water bodies.

La distribución del complejo Aspidoscelis gularis en México ha sido difícil de modelar debido a los problemas taxonómicos que enfrentan sus integrantes y a que los modelos publicados excluyen zonas típicas donde los taxones han sido reportados. El objetivo de este trabajo fue actualizar la información sobre la distribución del complejo A. gularis y proponer un modelo aplicable a grupos de especies considerados “complejos”, así como para cualquier nivel taxonómico. La información generada permitió desarrollar un modelo de distribución con el algoritmo Tipicidad de Mahalanobis en IDRISI Taiga y se validó con el área bajo la curva (AUC), la cual obtuvo un valor de 0.932. La distribución modelada abarcó estados pertenecientes al Altiplano Mexicano. Se encontró que los taxones del complejo están asociados con la vegetación característica del Altiplano Mexicano clasificada como desierto Chihuahuense compuesta principalmente por matorrales xerófilos y pastizales, lo que sugiere un factor que limita su distribución en el norte hasta el centro de México, similar con otros grupos de reptiles.

CienciaUAT RESUMENLa caracterización geomorfológica es una herramienta para la instrumentación de programas relacionados con el uso y manejo del territorio, la planeación geográfica integral, la evaluación de paisajes y de escenarios relacionados con riesgos en las regiones. En el presente estudio se realizó la cartografía geomorfológica del complejo volcánico Nevado de Toluca -San Antonio, usando criterios morfológicos y morfográficos en escala de trabajo 1:50 000 del Área Natural Protegida Nevado de Toluca, localizada sobre el paralelo 190 en el Estado de México. La carta geomorfológica representa los elementos de origen tectónico, la morfología volcánica de edificios, relieve explosivo y efusivo; así como la constitución de cimas y parteaguas, sistemas de laderas, y procesos glaciares y fluviales. Este trabajo permitió relacionar los ritmos y procesos eruptivos del volcán con la configuración de su actual morfología, a través de ciclos de construcción-destrucción, en diversos períodos y sectores de los edificios.PALABRAS CLAVE: geomorfología, Área Natural Protegida, relieve, cartografía. ABSTRACTGeomorphological characterization is a tool for the implementation of programs related to use and management of territory, comprehensive geographical planning, evaluation of landscapes, and risk scenarios of regions This study consisted in creating a geomorphological map of the Nevado de Toluca -San Antonio volcano complex, using morphological and morphographic criteria on scale 1:50 000 of the Natural Protected Area Nevado de Toluca, located on parallel 190 in the State of Mexico. The geomorphology map shows elements of tectonic origin, volcanic edifice, explosive and effusive relief, as well as formation of peaks, watersheds, systems of slopes, and glacial and fluvial processes. The study found relationships between the rhythms and eruptive processes of the volcanoes and their actual morphology, through construction-deconstruction cycles

Rainfall implications on body size evolution of Aspidoscelis gularis (Squamata: Teiidae). Life history traits are highly variable attributes that maximize organisms's fitness. The relationship of weight and body size with environmental changes and habitat heterogeneity has been documented in previous reports; and size and body shapes are both considered life history attributes that are associated with rainfall, that boost available resources in the environment. While in Aspidoscelis genus, clutch size and relative mass are mainly associated with latitude and altitude, in Aspidoscelis gularis, winter rainfall favors two reproductive seasons, which may determine season variable clutch size. With the aim to study this, samplings were undertaken from May-July 2013, and May-September 2015. A total of 65 individuals lizards of the Southeast clade were obtained, and body length and interaxilar distance measurements were taken; furthermore, hepatic tissue samples were taken for DNA extraction, which allowed us to analyze phylogenetic relationships through a Bayesian Inference analysis, and subsequently, to apply Phylogenetic Comparative Methods (like phylogenetic signal, phylogenetically independent contrasts and reconstruction of ancestral character). Our results showed that there is a low phylogenetic signal regarding body size and shape, while the phylogenetically independent contrasts and reconstruction of ancestral characters suggest that small body sizes are associated to locations with highest rainfall. This can be associated to an establishment of an early sexual maturity, which reflects the maximum size of adults. Furthermore, according to an ANOVA and ANCOVA, there were statistically significant differences in body size and shape respectively, which promote a system for sexual competition for males and a system for fertility in females. These results were important to determine the effect of rainfall on some life history traits, pointing out that lizards of the Southeast clade, belonging to the A. gularis complex were able to face different selection pressures, determined by the environment. Rev. Biol. Trop. 65 (2): 725-733. Epub 2017 June 01.

<p>El género <em>Aspidoscelis </em>es un grupo de lagartijas distribuido ampliamente en México, los miembros del género son semejantes en características, morfológicas, ecológicas, fisiológicas y conductuales a lo largo de su distribución; presentan modo de paridad ovípara, son forrajeros activos con preferencia por los hábitats abiertos y con temperaturas corporales elevadas. Debido a estas similitudes y a los eventos de hibridación frecuentes al interior del grupo, <em>Aspidoscelis </em>es considerado un género complicado, con relaciones filogenéticas aún por resolver.<strong></strong></p>