Seleção de habitat por espécies de aranhas em uma caverna calcária

Abstract

The purpose of this study was to evaluate habitat selection of four spider species and the influence of environmental parameters in a cave environment. These include distance from the entrance, height from the ground, substrate heterogeneity, floor and wall inclination, luminosity, temperature, air moisture, wind strength and food availability (potential prey). For this study, the species Oecobius navus Blackwall, 1859, Loxosceles anomala Mello-Leitão, 1917, Scytodes itapevi Brescovit & Rheims, 2000 and Philoponella vittata Keyserling, 1881 were selected, given their wide distribution throughout the Duca cave, in the municipality of Pains, in the State of Minas Gerais, Brazil. Secondly, due to its greater abundance, we evaluated the spatial distribution pattern of O. navus within a limestone cave. The first manuscript was prepared according to The Journal of Arachnology guidelines. In this study, we aimed to evaluate which environmental parameters determine, across different temporal and spatial scales, habitat selection and distribution of four spider species. The second manuscript was prepared according to the guidelines established by the journal Subterranean Biology, which aimed to analyze the spatial distribution pattern of Oecobius navus, at different temporal and spatial scales. The main results indicate that the selected spider species showed different habitat preferences, probably related to their physiological and ecological requirements. Such is the case with Oecobius navus, which showed preference for sections with light, where the Loxosceles anomala, Scytodes itapevi and Philoponella vittata do not usually occur. The latter tended to select less iluminated and more humid areas of the cave. Oecobius navus exhibits territorial behavior and lives under conditions of low prey abundance and considerable environmental homogeneity. Such factors are likely to determine the predominantly random microscale spatial distribution pattern within the cave. On the other hand, the creation of aggregations on a meso-scale was probably due to the selection of cave sites with certain environmental requirements, including light and wind conditions.