Molecular genetic diversity and differentiation of Nile tilapia (Oreochromis niloticus, L. 1758) in East African natural and stocked populations
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...
| Main Authors: | , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
BMC
2020-01-01
|
| Series: | BMC Evolutionary Biology |
| Subjects: | |
| Online Access: | https://doi.org/10.1186/s12862-020-1583-0 |
| _version_ | 1818578975094472704 |
|---|---|
| author | Papius Dias Tibihika Manuel Curto Esayas Alemayehu Herwig Waidbacher Charles Masembe Peter Akoll Harald Meimberg |
| author_facet | Papius Dias Tibihika Manuel Curto Esayas Alemayehu Herwig Waidbacher Charles Masembe Peter Akoll Harald Meimberg |
| author_sort | Papius Dias Tibihika |
| collection | DOAJ |
| description | 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 was genetically more divergent (Fst = 2.1) than expected suggesting that it might be a different sub-species. In East Africa, the genetic structure was congruent with both geographical location and anthropogenic activities (Isolation By Distance for East Africa, R2 = 0.67 and Uganda, R2 = 0.24). 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 in genetic diversity, which can be a consequence of bottleneck (G-W, < 0.5) caused by overfishing, genetic erosion due to fragmentation or founder effect resulting from stocking activities. Conclusions The anthropogenic activities particularly in the East African O. niloticus translocations, promoted artificial admixture among Nile Tilapia populations. Translocations may also have triggered hybridization with the native congenerics, which needs to be further studied. These events may contribute to outbreeding depression and hence compromising the sustainability of the species in the region. |
| first_indexed | 2024-12-16T06:54:20Z |
| format | Article |
| id | doaj.art-f234fd3a85fa4217b09eaa42ee41e826 |
| institution | Directory Open Access Journal |
| issn | 1471-2148 |
| language | English |
| last_indexed | 2024-12-16T06:54:20Z |
| publishDate | 2020-01-01 |
| publisher | BMC |
| record_format | Article |
| series | BMC Evolutionary Biology |
| spelling | doaj.art-f234fd3a85fa4217b09eaa42ee41e8262022-12-21T22:40:20ZengBMCBMC Evolutionary Biology1471-21482020-01-0120112010.1186/s12862-020-1583-0Molecular genetic diversity and differentiation of Nile tilapia (Oreochromis niloticus, L. 1758) in East African natural and stocked populationsPapius Dias Tibihika0Manuel Curto1Esayas Alemayehu2Herwig Waidbacher3Charles Masembe4Peter Akoll5Harald Meimberg6Institute for Integrative Nature Conservation Research, University of Natural Resources and Life Sciences Vienna (BOKU)Institute for Integrative Nature Conservation Research, University of Natural Resources and Life Sciences Vienna (BOKU)National Agricultural Research Organization, Kachwekano Zonal Agricultural Research and Development InstituteNational Fishery and Aquatic Life Research CentreDepartment of Zoology, Entomology and Fisheries Sciences-Makerere University KampalaDepartment of Zoology, Entomology and Fisheries Sciences-Makerere University KampalaInstitute for Integrative Nature Conservation Research, University of Natural Resources and Life Sciences Vienna (BOKU)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 was genetically more divergent (Fst = 2.1) than expected suggesting that it might be a different sub-species. In East Africa, the genetic structure was congruent with both geographical location and anthropogenic activities (Isolation By Distance for East Africa, R2 = 0.67 and Uganda, R2 = 0.24). 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 in genetic diversity, which can be a consequence of bottleneck (G-W, < 0.5) caused by overfishing, genetic erosion due to fragmentation or founder effect resulting from stocking activities. Conclusions The anthropogenic activities particularly in the East African O. niloticus translocations, promoted artificial admixture among Nile Tilapia populations. Translocations may also have triggered hybridization with the native congenerics, which needs to be further studied. These events may contribute to outbreeding depression and hence compromising the sustainability of the species in the region.https://doi.org/10.1186/s12862-020-1583-0CichlidsFish translocationsGenetic structureGene flowBottleneck |
| spellingShingle | Papius Dias Tibihika Manuel Curto Esayas Alemayehu Herwig Waidbacher Charles Masembe Peter Akoll Harald Meimberg Molecular genetic diversity and differentiation of Nile tilapia (Oreochromis niloticus, L. 1758) in East African natural and stocked populations BMC Evolutionary Biology Cichlids Fish translocations Genetic structure Gene flow Bottleneck |
| title | Molecular genetic diversity and differentiation of Nile tilapia (Oreochromis niloticus, L. 1758) in East African natural and stocked populations |
| title_full | Molecular genetic diversity and differentiation of Nile tilapia (Oreochromis niloticus, L. 1758) in East African natural and stocked populations |
| title_fullStr | Molecular genetic diversity and differentiation of Nile tilapia (Oreochromis niloticus, L. 1758) in East African natural and stocked populations |
| title_full_unstemmed | Molecular genetic diversity and differentiation of Nile tilapia (Oreochromis niloticus, L. 1758) in East African natural and stocked populations |
| title_short | Molecular genetic diversity and differentiation of Nile tilapia (Oreochromis niloticus, L. 1758) in East African natural and stocked populations |
| title_sort | molecular genetic diversity and differentiation of nile tilapia oreochromis niloticus l 1758 in east african natural and stocked populations |
| topic | Cichlids Fish translocations Genetic structure Gene flow Bottleneck |
| url | https://doi.org/10.1186/s12862-020-1583-0 |
| work_keys_str_mv | AT papiusdiastibihika moleculargeneticdiversityanddifferentiationofniletilapiaoreochromisniloticusl1758ineastafricannaturalandstockedpopulations AT manuelcurto moleculargeneticdiversityanddifferentiationofniletilapiaoreochromisniloticusl1758ineastafricannaturalandstockedpopulations AT esayasalemayehu moleculargeneticdiversityanddifferentiationofniletilapiaoreochromisniloticusl1758ineastafricannaturalandstockedpopulations AT herwigwaidbacher moleculargeneticdiversityanddifferentiationofniletilapiaoreochromisniloticusl1758ineastafricannaturalandstockedpopulations AT charlesmasembe moleculargeneticdiversityanddifferentiationofniletilapiaoreochromisniloticusl1758ineastafricannaturalandstockedpopulations AT peterakoll moleculargeneticdiversityanddifferentiationofniletilapiaoreochromisniloticusl1758ineastafricannaturalandstockedpopulations AT haraldmeimberg moleculargeneticdiversityanddifferentiationofniletilapiaoreochromisniloticusl1758ineastafricannaturalandstockedpopulations |