Diversidade molecular dos camarões de água doce do grupo Macrobrachium amazonicum (Heller, 1862) (Decapoda, Palaemonidae) nas ecorregiões hidrográficas do nordeste do Brasil

• Ano de defesa: 2018
• Autor(a) principal: Xavier, Ana Carolina Carvalho
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Brasil; UFRN; PROGRAMA DE PÓS-GRADUAÇÃO EM SISTEMÁTICA E EVOLUÇÃO
• Palavras-chave em Português: Filogeografia; Introdução de espécies; Complexo de espécies; DNA mitocondrial; Macrobrachium pantanalense; CNPQ::CIENCIAS BIOLOGICAS: SISTEMÁTICA E EVOLUÇÃO
• Link de acesso: https://repositorio.ufrn.br/jspui/handle/123456789/26468

Macrobrachium amazonicum (Heller, 1862) is a species of freshwater prawns with wide geographical distribution in the Neotropical region and of great socioeconomic importance in Brazil. The species is found in several cisandian hydrographic ecoregions, occurring from large hydrographic basins, such as the Amazon and Paraná-Paraguay rivers, to smaller coastal basins in different phytophysiognomic domains. However, part of this occurrence may be due to anthropic introductions. Because it is a freshwater species, it is expected that the dispersion will be limited and that it will present population structuring related to the hydrographic ecoregions. But occurrence in estuarine areas may allow connection between adjacent watersheds. Despite this, few studies on the systematics and geographic distribution of this species were carried out in the Brazilian northeast, where the species was supposedly introduced. The present study aims to investigate the molecular diversity of the shrimp strains of the M. amazonicum group of the ecoregions of the Brazilian northeast (Maranhão-Piauí, Northeast Middle East and São Francisco), in order to determine if the genetic structure of the species is related to hydrographic ecoregions, and to verify possible areas of introduction of the species. Mitochondrial DNA sequences of the cytochrome oxidase subunit I gene (COI) and phylogenetic and phylogeographic analyzes were used. The molecular data showed the existence of three clades - Amazonas, Coastal and Paraná/Paraguay. Northeastern Brazilian specimens belong to the coastal clade and present low haplotypic diversity in the ecoregion of the Northeast of the Middle East, as well as haplotypes similar to those in the Amazon Estuary ecoregion, and distinct from the adjacent ecoregion (Maranhão-Piauí), corroborating the hypothesis that the populations of this region, as well as the ecoregion of the Upper Paraná, also with low haplotype diversity, are in fact derived from anthropogenic introductions. This information on the evolution and geographic distribution of the M. amazonicum group in Brazil can help in the management and conservation, when recognizing a distinct lineage, as occurred with the description of M. pantanalense Santos, Hayd & Anger, 2013, the results of the delimitations of lineages and distance values p indicate a possible new species within this group, as well as it is possible to recognize areas of anthropic introduction.