16ª JORNADAS DEL GRUPO IBÉRICO DE ARACNOLOGÍA         Assessing heritability in physiological and morphological traits in the wolf spider Lycosa fasciiventris: Implications for eco-evolutionary dynamics           Jorge F. Henriques*1,3, Mariángeles Lacava2, Celeste Guzman3, Eva De Mas3, Sara Magalhães1, Jordi Moya-Laraño3           1cE3c - Centre for Ecology, Evolution and Environmental Changes, Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal.           2Laboratorio de Ecología del Comportamiento, Instituto de Investigaciones Biológicas Clemente Estable, Avenida Italia 3318, Montevideo, Uruguay.           3Functional and Evolutionary Ecology, Estación Experimental de Zonas Áridas, CSIC, Carretera de Sacramento s/n, 04120-La Cañada De San Urbano, Almería, Spain.           Quantitative genetics is a field stuy that studies the inheritance of continuous/metric traits/phenotypes. Additive genetic proportion of genetic variation in a given population (narrow-sense heritability, h2) is an important parameter for predicting evolutionary trajectories. Taking this into consideration, determining the amount of additive genetic variation in physiological traits and its relationship with fitness is of major importance in understanding and predicting how populations may cope with current and future environmental stressors (e.g. climate change). In this study, we assessed the additive genetic variation of some physiological and morphological traits in populations of the wolf-spider Lycosa fasciventris, a common wolf-spider in the Iberian Peninsula. A half-sib split-brood design was used to evaluate additive genetic effects, heritability and genetic correlations in a series of life-history traits including body size, body condition and assimilation efficiency. Spiderlings of 50 sire and 100 dam families were raised under two feeding treatments, in which 3 spiderlings within each brood were fed three times more food than the remaining 9 spiderlings. This last procedure with the objective of assessing phenotypic plasticity and genotype-environment interactions due to dietary effects. Our preliminary results show negligible heritability for body size at birth and assimilation efficiency, but moderately high heritability for body condition at birth. The data presented here is part of a bigger study in which we intend to correlate a series of life-history and behavioral traits which altogether, may provide the best quantitative genetic estimates in funcional traits for a soil top predator to date. Compilation of these data will allow to draw relevant predictions for eco-evolutionary feedback loops within soil food webs.           Keywords: Quantitative genetics, body condition, size, food webs.