A new species of the mygalomorph spider genus Euagrus Ausserer (Araneae: Euagridae) from central Mexico and new records of E. gus Coyle from Tlaxcala

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  A new species of the mygalomorph spider genus Euagrus Ausserer (Araneae: Euagridae) from central Mexico and new records of E. gus Coyle from Tlaxcala Abstract  A new species of the spider genus Euagrus Ausserer, 1875 from temperate pine-oak forests in the states of Tlaxcala and Hidalgo, Mexico is described: E. pulque sp. nov. The description of the new species is based on male and female adult specimens. Additionally, Euagrus gus Coyle, 1988 is recorded for the very first time in the state of Tlaxcala. These species have sympatric distributions in La Malinche National Park, Tlaxcala. With this description, the diversity of the genus increases to 23 species, with Mexico harboring the highest diversity with 17 described species.  Valdez-Mondragón, A., Salinas-Velasco, H. V. & Bueno-Villegas, J. (2026). A new species of the mygalomorph spider genus Euagrus Ausserer (Araneae: Euagridae) from central Mexico and new records of E. gus Coyle from Tlaxcala. Zootaxa 5810 (...

How spider diversity and traits interact with environmental variables in riparian sandy bars

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How spider diversity and traits interact with environmental variables in riparian sandy bars

Abstract

Spider ecology and functional traits were analysed within side bars (SB) of the middle Paraná River, investigating their relationship with environmental variables. Pitfall traps were utilized to capture spiders during four seasonal surveys spanning the years 2018 to 2019 on three SB, characterized by varying hydrological conditions. These surveys were conducted across three pre-defined zones: Wet Zone (WZ), Temporally Exposed Zone (TEZ), and Permanently Dry Zone (PDZ). The three zones were significantly differentiated according to sedimentological variables, vegetation cover, humidity, and soil organic matter (SOM). A total of 732 spiders were collected, representing 21 families and 49 species. Lycosidae and Linyphiidae were notably dominant. The species Sphecozone ignigena, Glenognatha lacteovittata, and Agalenocosa grismadoi were the most abundant. The PDZ was the most diverse zone in terms of guilds (8), species (spp) and morphospecies (msp) (34), families (18) and total abundance (295), in addition to exhibiting the greatest vegetation cover. Analysis of beta diversity of species during the rising limb of water flow revealed that replacement exceeded nesting levels in all seasons studied, indicating that most of the beta diversity was attributable to replacement. Furthermore, specific associations were observed within spider guilds. This study was a pioneer in exclusively examining the spider communities on the banks of the second longest river in South America and analysing how their ecology and functional traits behave under different environmental variables.
Segovia, L. N., Garello, N. A., Saigo, M., Blettler, M. C., Grismado, C. J., & Rodrigues, S. (2024). How spider diversity and traits interact with environmental variables in riparian sandy bars. Ecohydrology & Hydrobiology. https://doi.org/10.1016/j.ecohyd.2024.11.001