Connectivity between Easter Island and Salas y Gómez Island: population genetic differentiation of culturally important fish Kyphosus sandwicensis (Sauvage, 1880).
Population connectivity has a fundamental role in metapopulation dynamics and population resilience after disturbances, due to that, it has important implications for the population persistence in space and time. In this regard, island systems as Easter Island (IP) and the island Salas y Gómez (SG),...
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| Formato: | tesis de maestría |
| Estado: | Versión publicada |
| Fecha de publicación: | 2018 |
| País: | Chile |
| OAI Identifier: | oai:repositorio.anid.cl:10533/232864 |
| Acesso em linha: | https://hdl.handle.net/10533/232864 |
| Access Level: | acceso abierto |
| Palavra-chave: | Ciencias Naturales Ciencias de la Tierra y del Medio Ambiente Ecología |
| Resumo: | Population connectivity has a fundamental role in metapopulation dynamics and population resilience after disturbances, due to that, it has important implications for the population persistence in space and time. In this regard, island systems as Easter Island (IP) and the island Salas y Gómez (SG), are ideal places for studying connectivity model, because they are two isolated systems in the Pacific Ocean, where the migration process would playing a critical role to the persistence of their populations. The aim of this thesis was to determine the genetic population structure and historical migration patterns of Kyphosus sandwicensis between IP and SG. Through the use of mitochondrial markers (COI and Region Control) it was attempted a molecular identification of the species and assess the existence of phylogeographic structure. Finally, using 16 microsatellite described for the species, it was estimated the degree of genetic differentiation between the geographic populations and the reciprocal migration pattern. The COI gene showed high similarity with the species K. sectatrix and K. bigibbus, indicating that our individuals could correspond to one of these species. The Control Region did not detect a Phylogeographical pattern, pointed out that populations of IP and SG have not been separated in the time. Moreover, the genetic variability of the microsatellites analyzed did not show differences between the allelic frequency of the individuals from IP and SG so they would be part of the same population. The two islands showed high and similar rates of genetic diversity and allelic richness nucleotide, coinciding with the absence of recent bottleneck. Historical migration analyzes suggest migration in both directions, being higher from SG to IP. Our results of connectivity between IP and SG are the first evidence of a genetic connectivity between these two oceanic islands. These migrations would be potentially determined by the oceanographic conditions predominant in the area, which includes: oceanographic discontinuities, ocean currents fluctuations, mesoscale eddies, and by the probable dispersal mechanism of k. sandwicensis by rafting in Sargassum algae which could provide the opportunity to disperse large distances and allows us to understand how a population composed of individuals separated by 415km, can maintain genetic connectivity. |
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