Aspectos populacionais em espécies de crustáceos do gênero Hyalella em diferentes ambientes da América do Sul

Abstract

The study of population dynamics plays a fundamental role in understanding the persistence and resilience of populations over time, as well as in formulating effective preservation measures. A comprehensive analysis of these studies allows for the identification of shared patterns among organisms within the same genus, providing a more holistic view of population interactions. Amphipod crustaceans of the genus Hyalella, found throughout South America, exhibit a wide diversity. Despite various population studies conducted on this diversity, significant gaps persist. Two specific gaps are identified in this context. The first emphasizes the need to expand studies to encompass all described species, while the second focuses on understanding patterns within the life histories of these species. Therefore, the central aim of this thesis is to explore the ecological aspects of both epigean and hypogean species of Hyalella and evaluate possible patterns that may emerge in similar environments. To achieve this objective, the thesis is divided into three articles. The first article comprises a systematic review of population studies related to the Hyalella genus in South America. The second focuses on analyzing population aspects of a specific troglobitic species, H. veredae. Finally, the third article investigates the population structure of a recently discovered and yet undescribed species, referred to as Hyalella sp. This extensive study on the ecology of the Hyalella genus has revealed common patterns in population dynamics, particularly when considering ecoregions, contradicting some latitude-based hypotheses proposed by other researchers. Additionally, even in subterranean environments, it has been observed that geographically proximate species, whether epigean or hypogean, may share similarities in their population structures. This thesis provides significant insights that enrich the understanding of Hyalella ecology, contributing to the expansion of knowledge in this research field.