2025-09-032025-09-032023-12-13NUNES, André Lucas Alves Dinâmica de especiação e expansão populacional em Ucides: insights a partir da análise genética de Ucides occidentalis (Ortmann, 1897) e Ucides cordatus (Linnaeus, 1763) (Decapoda, Brachyura). Orientador: Adam Rick Bessa da Silva. 2023. 21 f. Trabalho de Conclusão de Curso (Licenciatura em Ciências Biológicas) – Faculdade de Ciências Biológicas. Instituto de Estudos Costeiros, Campus Universitário de Bragança, Universidade Federal do Pará, Bragança-PA, 2023. Disponível em: https://bdm.ufpa.br/handle/prefix/8527. Acesso em: .https://bdm.ufpa.br/handle/prefix/8527The genus Ucides, consisting of the species Ucides occidentalis and Ucides cordatus, is widely distributed along the Atlantic and Pacific coasts of Central and South America. These species are crucial for studying the evolution and historical distribution of coastal organisms. Their geographical distribution suggests a vicariance event, possibly due to geological and climatic changes, which would have separated an ancestral population and led to speciation. This study analyzed 116 genetic sequences (46 from U. occidentalis and 70 from U. cordatus), using the COI gene to confirm the taxonomic status of the Ucides subspecies. The genetic divergence between the lineages varied from 0.152 to 0.192% in p-distance, with a temporal divergence estimate of about 2.7 million years. No significant substructures were found within each group, indicating panmictic populations for both species. BSP analyses showed a population growth that began about 15,000 years ago, for both species. The recent demographic expansion is related to the end of the Last Glacial Maximum and the expansion of mangroves, highlighting the importance of these findings for understanding the evolution, population dynamics, and conservation of these species.Acesso AbertoUcides occidentalisUcides cordatusRegião NeotropicalManguezaisConservaçãoNeotropical RegionMangrovesConservationCNPQ::CIENCIAS BIOLOGICAS::GENETICA::GENETICA ANIMALTrabalho de Curso - Graduação - MonografiaAttribution-NonCommercial-NoDerivs 3.0 Brazil