scholarly journals Outbreaks and genetic diversity of Francisella noatunensis subsp orientalis isolated from farm-raised Nile tilapia (Oreochromis niloticus) in Brazil

2014 ◽  
Vol 13 (3) ◽  
pp. 5704-5712 ◽  
Author(s):  
C.A.G. Leal ◽  
G.C. Tavares ◽  
H.C.P. Figueiredo
Keyword(s):  
Genetic Diversity ◽  
Oreochromis Niloticus ◽  
Nile Tilapia ◽  
Nile Tilapia Oreochromis Niloticus

scholarly journals Molecular genetic diversity and differentiation of Nile tilapia (Oreochromis niloticus, L. 1758) in East African natural and stocked populations

2019 ◽  
Author(s):  
Papius Dias Tibihika ◽  
Manuel Curto ◽  
Esayas Alemayehu ◽  
Herwig Waidbacher ◽  
Charles Masembe ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
East Africa ◽  
Oreochromis Niloticus ◽  
Nile Tilapia ◽  
Anthropogenic Activities ◽  
Genetic Erosion ◽  
Gene Pools ◽  
East African ◽  
Nile Tilapia Oreochromis Niloticus

Abstract Background The need for enhancing the productivity of fisheries in Africa triggered the introduction of non-native fish, causing dramatic changes to local species. In East Africa, the extensive translocation of Nile tilapia (Oreochromis niloticus) is one of the major factors in this respect. Using 40 microsatellite loci with SSR-GBS techniques, we amplified a total of 664 individuals to investigate the genetic structure of O. niloticus from East Africa in comparison to Ethiopian and Burkina Faso populations. Results All three African regions were characterized by independent gene-pools, however, the Ethiopian population from lake Tana showed to be more divergent than expected suggesting that it might be a different species. In East Africa, the genetic structure was congruent with both geographical location and anthropogenic activities. O. niloticus from Lake Turkana (Kenya) was isolated, while in Uganda, despite populations being rather similar to each other, two main natural catchments were able to be defined. We show that these two groups contributed to the gene-pool of different non-native populations. Moreover, admixture and possible hybridization with other tilapiine species may have contributed to the genetic divergence found in some populations such as Lake Victoria. We detected other factors that might be affecting Nile tilapia genetic variation. For example, most of the populations have gone through a reduction of genetic diversity, which can be a consequence of bottleneck caused by overfishing, genetic erosion due to fragmentation or founder effect resulting from stoking activities. Conclusions The anthropogenic activities particularly in the East African O. niloticus translocations, promoted admixture and contact with the native congenerics which may contribute to outbreeding depression and hence compromising the sustainability of the species in the region.

scholarly journals Population Structure and Genetic Diversity of Nile Tilapia (Oreochromis niloticus) Strains Cultured in Tanzania

2019 ◽  
Vol 10 ◽  
Author(s):  
Redempta A. Kajungiro ◽  
Christos Palaiokostas ◽  
Fernando A. Lopes Pinto ◽  
Aviti J. Mmochi ◽  
Marten Mtolera ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Oreochromis Niloticus ◽  
Nile Tilapia ◽  
Nile Tilapia Oreochromis Niloticus

scholarly journals Molecular genetic diversity and differentiation of Nile tilapia (Oreochromis niloticus, L. 1758) in East African natural and stocked populations

2019 ◽  
Author(s):  
Papius Dias Tibihika ◽  
Manuel Curto ◽  
Esayas Alemayehu ◽  
Herwig Waidbacher ◽  
Charles Masembe ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
East Africa ◽  
Oreochromis Niloticus ◽  
Nile Tilapia ◽  
Anthropogenic Activities ◽  
Genetic Erosion ◽  
Gene Pools ◽  
East African ◽  
Nile Tilapia Oreochromis Niloticus

Abstract Background The need for enhancing the productivity of fisheries in Africa triggered the introduction of non-native fish, causing dramatic changes to local species. In East Africa, the extensive translocation of Nile tilapia (Oreochromis niloticus) is one of the major factors in this respect. Using 40 microsatellite loci with SSR-GBS techniques, we amplified a total of 664 individuals to investigate the genetic structure of O. niloticus from East Africa in comparison to Ethiopian and Burkina Faso populations. Results All three African regions were characterized by independent gene-pools, however, the Ethiopian population from lake Tana showed to be more divergent than expected suggesting that it might be a different species. In East Africa, the genetic structure was congruent with both geographical location and anthropogenic activities. O. niloticus from Lake Turkana (Kenya) was isolated, while in Uganda, despite populations being rather similar to each other, two main natural catchments were able to be defined. We show that these two groups contributed to the gene-pool of different non-native populations. Moreover, admixture and possible hybridization with other tilapiine species may have contributed to the genetic divergence found in some populations such as Lake Victoria. We detected other factors that might be affecting Nile tilapia genetic variation. For example, most of the populations have gone through a reduction of genetic diversity, which can be a consequence of bottleneck caused by overfishing, genetic erosion due to fragmentation or founder effect resulting from stoking activities. Conclusions The anthropogenic activities particularly in the East African O. niloticus translocations, promoted admixture and contact with the native congenerics which may contribute to outbreeding depression and hence compromising the sustainability of the species in the region.

Virulotyping and genetic diversity of Aeromonas hydrophila isolated from Nile tilapia (Oreochromis niloticus) in aquaculture farms in Egypt

Aquaculture ◽  
2021 ◽  
pp. 736781
Author(s):  
Yasmine H. Tartor ◽  
El-Sayed Y. EL-Naenaeey ◽  
Hossam M. Abdallah ◽  
Mohamed Samir ◽  
Mayada M. Yassen ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Aeromonas Hydrophila ◽  
Oreochromis Niloticus ◽  
Nile Tilapia ◽  
Nile Tilapia Oreochromis Niloticus

scholarly journals Molecular genetic diversity and differentiation of Nile tilapia (Oreochromis niloticus, L. 1758) in East African natural and stocked populations

2019 ◽  
Author(s):  
Papius Dias Tibihika ◽  
Manuel Curto ◽  
Esayas Alemayehu ◽  
Herwig Waidbacher ◽  
Charles Masembe ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
East Africa ◽  
Oreochromis Niloticus ◽  
Nile Tilapia ◽  
Anthropogenic Activities ◽  
Genetic Erosion ◽  
Gene Pools ◽  
East African ◽  
Nile Tilapia Oreochromis Niloticus

Abstract Background The need for enhancing the productivity of fisheries in Africa triggered the introduction of non-native fish, causing dramatic changes to local species. In East Africa, the extensive translocation of Nile tilapia (Oreochromis niloticus) is one of the major factors in this respect. Using 40 microsatellite loci with SSR-GBS techniques, we amplified a total of 664 individuals to investigate the genetic structure of O. niloticus from East Africa in comparison to Ethiopian and Burkina Faso populations. Results All three African regions were characterized by independent gene-pools, however, the Ethiopian population from lake Tana showed to be more divergent than expected suggesting that it might be a different species. In East Africa, the genetic structure was congruent with both geographical location and anthropogenic activities. O. niloticus from Lake Turkana (Kenya) was isolated, while in Uganda, despite populations being rather similar to each other, two main natural catchments were able to be defined. We show that these two groups contributed to the gene-pool of different non-native populations. Moreover, admixture and possible hybridization with other tilapiine species may have contributed to the genetic divergence found in some populations such as Lake Victoria. We detected other factors that might be affecting Nile tilapia genetic variation. For example, most of the populations have gone through a reduction of genetic diversity, which can be a consequence of bottleneck caused by overfishing, genetic erosion due to fragmentation or founder effect resulting from stoking activities. Conclusions The anthropogenic activities particularly in the East African O. niloticus translocations, promoted admixture and contact with the native congenerics which may contribute to outbreeding depression and hence compromising the sustainability of the species in the region.

scholarly journals Molecular genetic diversity and differentiation of Nile tilapia (Oreochromis niloticus, L. 1758) in East African natural and stocked populations

2020 ◽  
Author(s):  
Papius Dias Tibihika ◽  
Manuel Curto ◽  
Esayas Alemayehu ◽  
Herwig Waidbacher ◽  
Charles Masembe ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
East Africa ◽  
Oreochromis Niloticus ◽  
Nile Tilapia ◽  
Anthropogenic Activities ◽  
Genetic Erosion ◽  
Gene Pools ◽  
East African ◽  
Nile Tilapia Oreochromis Niloticus

Abstract Background The need for enhancing the productivity of fisheries in Africa triggered the introduction of non-native fish, causing dramatic changes to local species. In East Africa, the extensive translocation of Nile tilapia (Oreochromis niloticus) is one of the major factors in this respect. Using 40 microsatellite loci with SSR-GBS techniques, we amplified a total of 664 individuals to investigate the genetic structure of O. niloticus from East Africa in comparison to Ethiopian and Burkina Faso populations. Results All three African regions were characterized by independent gene-pools, however, the Ethiopian population from lake Tana showed to be more divergent than expected suggesting that it might be a different species. In East Africa, the genetic structure was congruent with both geographical location and anthropogenic activities. O. niloticus from Lake Turkana (Kenya) was isolated, while in Uganda, despite populations being rather similar to each other, two main natural catchments were able to be defined. We show that these two groups contributed to the gene-pool of different non-native populations. Moreover, admixture and possible hybridization with other tilapiine species may have contributed to the genetic divergence found in some populations such as Lake Victoria. We detected other factors that might be affecting Nile tilapia genetic variation. For example, most of the populations have gone through a reduction of genetic diversity, which can be a consequence of bottleneck caused by overfishing, genetic erosion due to fragmentation or founder effect resulting from stoking activities. Conclusions The anthropogenic activities particularly in the East African O. niloticus translocations, promoted admixture and contact with the native congenerics which may contribute to outbreeding depression and hence compromising the sustainability of the species in the region.

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