O uso de morfometria e microqu?mica de ot?litos saggitae como ferramentas para investigar a conectividade populacional de Mugil liza (Valenciennes, 1836) na costa do sudeste do Brasil

• Ano de defesa: 2019
• Autor(a) principal: Silva, Jos? Paulo do Carmo
• Orientador(a): Ara?jo, Francisco Gerson
• Banca de defesa: Ara?jo, Francisco Gerson de, Tubino, Magda Fernandes de Andrade, Martins, Raquel Renn? M., Costa, Marcus Rodrigues da, Magalh?es, Jayme Santangelo
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal Rural do Rio de Janeiro
• Programa de Pós-Graduação: Programa de P?s-Gradua??o em Biologia Animal
• Departamento: Instituto de Ci?ncias Biol?gicas e da Sa?de
• País: Brasil
• Palavras-chave em Português: Conectividade; recursos pesqueiros; ot?litos; zonas costeiras
• Palavras-chave em Inglês: Connectivity; fishery resources; otoliths; molecular markers; coastal zones
• Área do conhecimento CNPq: Biotecnologia; Zoologia
• Link de acesso: https://tede.ufrrj.br/jspui/handle/jspui/5806

The study aims to investigate the connectivity of an important fishery resource along the southeastern Brazilian coast of (mullet, Mugil liza) between semi-closed coastal systems and the adjacent coastal zone, aiming to provide subsidies for preservation and sustainable use. Two approaches were used to achieve these objectives, which correspond to the two chapters of the Thesis: 1. Morphometry of the Sagittae otolith; 2. Biochemistry of the Sagittae otolith. The fishes were collected along about 612 km, covering the coast of the states of Rio de Jneiro and S?o Paulo, in the following semi-closed systems and in their respective adjacent coastal zones: estuaries of Santos/Guaruj? and proximities of Caraguatatuba/Ilha Bela; bays of Sepetiba/Ilha Grande and Guanabara; and the coastal lagoons of Saquaremma and Maric?. We investigated, through the two approaches, the existence of different population groups throughout the study area, the population connectivity between the systems and the stocks/populations, and the existence of different pattern of individual movements within the different systems (lagoons, bays and estuaries). In the first chapter we tested the existence of different stocks of mullets along the coast of the states of S?o Paulo and Rio de Janeiro. Assuming that different morphotypes and/or variations in otolith shape may represent different populations/stocks, we tested the hypothesis that there is more than one Mugil liza stock/population across the study area. For this, we used Fourier elliptical descriptors and morphometric indices to identify variations in the shape of otoliths throughout the study area. A geographical pattern of separation, suggesting the existence of at least two stocks/populations throughout the study area was detected, and the presence of three otolith morphotypes that did not show a clinal distribution pattern was found, suggesting that the study area is a transition area for different stocks / populations of M. liza. In the second chapter, the patterns of movement and use of semi-closed systems and open coastal zone were studied. Assuming that mullets use estuarine systems during the early phase of their life cycle and migrate to the platform as adults, to be part of the migratory/spawning stock of the species. We tested the hypothesis that there is an individual differentiation of use, with some individuals returning to the estuarine environment after spawning and some others individuals do not need to exit estuarine systems to complete their life cycle. For this, the elemental strontium and barium profiles of the mullets captured within the main estuarine systems and respective coastal zone sites were evaluated. Sr concentrations along the nucleus-edge (life history) and nucleus (birth areas) axis suggest distinct populations / stocks and birth areas in both the adjacent platform and the estuarine region. Three movement profiles were identified, with the most common named Marine Visitors (MV), representing connections between estuarine and marine environments. The second profile was named Estuarine Resident Estuarine (ER), comprising individuals who remained in the estuarine environment during their life cycle. Finally, the third identified profile was named Marine Migrator (MM), represented by individuals who remained in estuarine environments during the early stages of the life cycle and apparently migrated permanently to the marine environment. In this study, the great plasticity of this species was observed in the use of adjacent estuarine and coastal environments, a possible adaptation to the euriraline conditions that allow the persistence of stocks / populations in high abundance in this transition region between the temperate and tropical areas of southeastern Brazil. Brazil.