Percorrer por autor "Mendonça, Fernando Fernandes"
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- Global phylogeography of the smooth hammerhead shark: glacial refugia and historical migration patternsPublication . Lopes da Silva Ferrette, Bruno; Coelho, Rui; Peddemors, Victor Marten; Ovenden, Jennifer R.; De Franco, Bruno Alexandre; Oliveira, Claudio; Foresti, Fausto; Mendonça, Fernando FernandesExtreme climate changes during the Cenozoic Era strengthened different biogeographical barriers that decreased the connectivity among populations, triggering lineage diversification of different species worldwide. The mitochondrial DNA control region was employed to explore the phylogeography of Sphyrna zygaena, a globally distributed species threatened by unsustainable, illegal, unreported and unregulated fisheries triggered by the international shark fin trade. It is listed as 'Vulnerable' by the IUCN Red List and its trade is regulated by CITES Appendix II. Only 13 haplotypes were found with low genetic diversity levels (hd = 0.686 +/- 0.014; pi = 0.00206 +/- 0.00004) compared with other species of the Sphyrnidae family. The species has a very strong phylogeographic population structure among the Atlantic, Indian and Pacific Oceans (phi(ST) = 0.79132). Worldwide, there are six distinct populations with some haplotype sharing. These populations are probably connected by a stepping-stone dispersal of a small number of migrants per generation from the Indo-Pacific towards the Atlantic. Modelling suggests that S. zygaena diverged into two lineages around 6.96 million years ago which have been isolated in glacial refuges in the Atlantic and Indo-Pacific oceans; and after deglaciation, a population expansion probably permitted secondary contact. Conservation plans to establish differentiated management units should be adopted in each of the identified populations. Among these, the Eastern Central Atlantic and West Indo-Pacific are the most important areas for the species considering the historical migration routes that act as a bridge connecting the Atlantic and Indo-Pacific Oceans while the Gulf of Guinea connects the Atlantic populations. Still, further studies are required to know if these populations are also linked with nursery areas for the species. The results herein can help to delimit the main evolutionarily significant units to implement effective policies to establish differentiated management units as starting points to genetic monitoring programmes for Sphyrna zygaena.
- Population genetics of the bigeye thresher shark Alopias superciliosus in the Atlantic and Indian Oceans: implications for conservationPublication . Morales, Millke Jasmine Arminini; Mendonça, Fernando Fernandes; Magalhães, Carolina Oliveira; Oliveira, Claudio; Coelho, Rui; Santos, Miguel Neves; Cruz, Vanessa Paes; Piercy, Andrew; Burgess, George; Hazin, Fabio Vieira; Foresti, FaustoPopulation structure and genetic connectivity are pivotal contributions to the establishment of conservation strategies for fisheries management, in particular for highly migratory species that are affected by commercial fisheries. This study used partial sequences of mitochondrial DNA control region to determine the genetic structure of the bigeye thresher shark Alopias superciliosus in the Atlantic and Indian Oceans. A total of 858 base pairs of mtDNA CR from 228 individuals were analyzed. The resulting nucleotide diversity (π) was 0.0011 ± 0.0008 and the haplotype diversity (h) was 0.127 ± 0.030. These are the lowest diversities registered in elasmobranchs with this genetic marker. Two genetically distinct lineages were identified, one of them represented by 3.9% of the analyzed individuals and none restricted to any particular area. Simulated scenarios of population structure, tested with AMOVA and pairwise ΦST did not result in significant values indicating high connectivity among all sampled groups. The absence of population structure, even between Atlantic and Indian Oceans, corroborates the high dispersal ability of this species. The low genetic diversity detected in this species and the identification of two historical lineages occurring in sympatry, one represented by a very small number of individuals, should be considered in the conservation efforts and management plans of A. superciliosus.
- Seascape genomics and phylogeography of the sailfish (Istiophorus platypterus)Publication . Ferrette, Bruno Lopes da Silva; Coimbra, Raphael T F; Winter, Sven; De Jong, Menno J; Williams, Samuel Mackey; Coelho, Rui; Rosa, Daniela; Rotundo, Matheus Marcos; Arocha, Freddy; Mourato, Bruno Leite; Mendonça, Fernando Fernandes; Janke, AxelPermeable phylogeographic barriers characterize the vast open ocean, boosting gene flow and counteracting population differentiation and speciation of widely distributed and migratory species. However, many widely distributed species consists of distinct populations throughout their distribution, evidencing that our understanding of how the marine environment triggers population and species divergence are insufficient. The sailfish is a circumtropical and highly migratory billfish that inhabits warm and productive areas. Despite its ecological and socioeconomic importance as a predator and fishery resource, the species is threatened by overfishing, requiring innovative approaches to improve their management and conservation status. Thus, we presented a novel high-quality reference genome for the species and applied a seascape genomics approach to understand how marine environmental features may promote local adaptation and how it affects gene flow between populations. We delimit two populations between the Atlantic and Indo-Western Pacific oceans and detect outlier loci correlated with sea surface temperature, salinity, oxygen, and chlorophyll concentrations. However, the most significant explanatory factor that explains the differences between populations was isolation by distance. Despite recent population drops, the sailfish populations are not inbred. For billfishes in general, genome-wide heterozygosity was found to be relatively low compared to other marine fishes, evidencing the need to counteract overfishing effects. In addition, in a climate change scenario, management agencies must implement state-of-the-art sequencing methods, consider our findings in their management plans, and monitor genome-wide heterozygosity over time to improve sustainable fisheries and the long-term viability of its populations.