2024-09-172024-09-172018-06-20ALVES, Rayssa Borges Dias. Myliobatis freminvillei (Lesuer, 1824), um novo caso crítico no Atlântico Sul Ocidental. Orientador: João Bráullio de Luna Sales. 2018. 40 f. Trabalho de Conclusão de Curso (Especialização em Educação em Ciências na Contemporaneidade) – Campus Universitário de Breves, Universidade Federal do Pará, Breves, 2018. Disponível em: https://bdm.ufpa.br/jspui/handle/prefix/7206 . Acesso em: .https://bdm.ufpa.br/jspui/handle/prefix/7206The class of the Chondrichthyes is represented by the elasmobranch (cartilaginous fishes), which it divides in two subclasses: (sharks and rays) and Holocephalii (Chimeras). The genus Myliobatis is composed for 11 valid species distributed around the world, where three are present along the Brazilian Coast: Myliobatis freminvillei (Lesueur, 1824), Myliobatis goodei (Garman, 1885) and Myliobatis ridens (Ruocco, Lucifora, Astarloa, Mabragaña & Delpiani, 2012). The taxonomy of the rays belonging to the Family Myliobatiformes remains unaltered for long time. However, recent study’s bringing new insights about the validity of the family as well, the presence of new undescribed species within the genus. The present study performs a molecular phylogeny of the Myliobatis genus, testing the efficiency of the DNA Barcoding tool for the resolution of the species within the genus. Individuals from Para and Sao Paulo State where the genes COI and RAG1 was amplified. The Results shows two main finding: 1-From the nine species utilized in the present study, seven was recovered as monophyletic taxa in all phylogenetic procedures; the exceptions were M. freminvillei e M. chilensis. For the first one, samples from southeastern Brazil are genetically different from sequences from USA; 2- No one of the Brazilian specimens was recovered as sister species where M. fremenvillei was recovered more closely related to M. californica, a species restricted to the Pacific Ocean (Mexico and California), while M. goodei was recovered as sister species of M. chilensis and finally, M. ridenswas recovered more closely to M. peruvianus. Additionally, our results indicate the presence of a new genetic lineage of M. freminvillei in Brazilian waters. This results show the importance of more accurated studies targeted for fauna of elasmobranch species in Southwestern Atlantic. More sampling efforts as well and a systematic review will be helping to clarify the delimitation of thi snew genetic lineage on the brazilian coast.Acesso AbertoElasmobrânquiosMyliobatisDNA BarcodingEspécie crípticaElasmobranchCryptic speciesCNPQ::CIENCIAS BIOLOGICAS::GENETICA::GENETICA MOLECULAR E DE MICROORGANISMOSTrabalho de Conclusão de Curso - Especialização