Morfologia funcional das estruturas alimentares de duas espécies simpátricas do gênero Aegla (crustacea, anomura, aeglidae).

Abstract

The Aeglidae family has an important participation in the decomposition of organic matter in streams of first and second order. This dissertation aims to analyze morphological characters in sympatric populations of Aegla abtao and Aegla denticulata (Decapoda, Anomura), compared to the same species, but in allopatric populations. When phylogenetically close species are comprised within the same geographical area, with preferences of similar habitats, competition may influence the evolution of morphological adaptations that allow coexistence, attenuating competition in the environment, and making them more specialized and differentiated in sympatry. Comparing the morphology of 39 individuals from each sympatric and allopatric population of A. abtao and A. denticulata. We performed the analysis of linear morphometry, external structures under study, the brief stomach analysis, 3D reconstruction and stomach gastric mill of the species studied. It was observed some differences between structures related to food, having a predisposition to smaller proportions, in A. abtao had a body decrease when in sympatry, and a change in the alimentary content together with differentiation of the gastric mill, in counterpart A. denticulata, possessed some differences in linear morphometry, but obtained more prominence in the differentiations in the margin of the cut of the dáctilo and in the number of horny scales. The food does not have large differences, except for the largest amount of carapace fragments in A. abtao. The study showed that the presence of other species may influence the morphological responses of A. denticulata and A. abtao, indicating that an increase in competitive pressure in the creek habitat will have consequences for the group, with changes not only in the occupational layout but also in the size and shape of food appendages and for the survival of these crustaceans. Depending on the variation of the responses, it can be stated that these are species-specific. Sympatric areas have the potential to alter the behavior of these eglids, which may alter their foraging behavior and act as a morphological modifier for food structures.