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Rick JA, Junker J, Kimirei IA, Sweke EA, Mosille JB, Dinkel C, Mwaiko S, Seehausen O, Wagner CE. The Genetic Population Structure of Lake Tanganyika's Lates Species Flock, an Endemic Radiation of Pelagic Top Predators. J Hered 2022; 113:145-159. [PMID: 35575081 PMCID: PMC9113442 DOI: 10.1093/jhered/esab072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 11/12/2021] [Indexed: 11/13/2022] Open
Abstract
Understanding genetic connectivity plays a crucial role in species conservation decisions, and genetic connectivity is an important component of modern fisheries management. In this study, we investigated the population genetics of four endemic Lates species of Lake Tanganyika (Lates stappersii, L. microlepis, L. mariae, and L. angustifrons) using reduced-representation genomic sequencing methods. We find the four species to be strongly differentiated from one another (mean interspecific FST = 0.665), with no evidence for contemporary admixture. We also find evidence for strong genetic structure within L. mariae, with the majority of individuals from the most southern sampling site forming a genetic group that is distinct from the individuals at other sampling sites. We find evidence for much weaker structure within the other three species (L. stappersii, L. microlepis, and L. angustifrons). Our ability to detect this weak structure despite small and unbalanced sample sizes and imprecise geographic sampling locations suggests the possibility for further structure undetected in our study. We call for further research into the origins of the genetic differentiation in these four species-particularly that of L. mariae-which may be important for conservation and management of this culturally and economically important clade of fishes.
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Affiliation(s)
- Jessica A Rick
- Department of Botany and Program in Ecology, University of Wyoming, 1000 E University Dr., Laramie, WY 82072, USA
| | - Julian Junker
- EAWAG Swiss Federal Institute of Aquatic Science and Technology, CH-6047 Kastanienbaum, Switzerland
- Division of Aquatic Ecology and Evolution, Institute of Ecology and Evolution, University of Bern, CH-3012 Bern, Switzerland
| | - Ismael A Kimirei
- Tanzania Fisheries Research Institute (TAFIRI), Dar es Salaam, Tanzania
| | - Emmanuel A Sweke
- Tanzania Fisheries Research Institute (TAFIRI), Dar es Salaam, Tanzania
- Deep Sea Fishing Authority (DSFA), Zanzibar, Tanzania
| | - Julieth B Mosille
- Tanzania Fisheries Research Institute (TAFIRI), Dar es Salaam, Tanzania
| | - Christian Dinkel
- EAWAG Swiss Federal Institute of Aquatic Science and Technology, CH-6047 Kastanienbaum, Switzerland
| | - Salome Mwaiko
- EAWAG Swiss Federal Institute of Aquatic Science and Technology, CH-6047 Kastanienbaum, Switzerland
- Division of Aquatic Ecology and Evolution, Institute of Ecology and Evolution, University of Bern, CH-3012 Bern, Switzerland
| | - Ole Seehausen
- EAWAG Swiss Federal Institute of Aquatic Science and Technology, CH-6047 Kastanienbaum, Switzerland
- Division of Aquatic Ecology and Evolution, Institute of Ecology and Evolution, University of Bern, CH-3012 Bern, Switzerland
| | - Catherine E Wagner
- Department of Botany and Program in Ecology, University of Wyoming, 1000 E University Dr., Laramie, WY 82072, USA
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Junker J, Rick JA, McIntyre PB, Kimirei I, Sweke EA, Mosille JB, Wehrli B, Dinkel C, Mwaiko S, Seehausen O, Wagner CE. Structural genomic variation leads to genetic differentiation in Lake Tanganyika's sardines. Mol Ecol 2020; 29:3277-3298. [PMID: 32687665 DOI: 10.1111/mec.15559] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 06/27/2020] [Accepted: 06/29/2020] [Indexed: 01/03/2023]
Abstract
Identifying patterns in genetic structure and the genetic basis of ecological adaptation is a core goal of evolutionary biology and can inform the management and conservation of species that are vulnerable to population declines exacerbated by climate change. We used reduced-representation genomic sequencing methods to gain a better understanding of genetic structure among and within populations of Lake Tanganyika's two sardine species, Limnothrissa miodon and Stolothrissa tanganicae. Samples of these ecologically and economically important species were collected across the length of Lake Tanganyika, as well as from nearby Lake Kivu, where L. miodon was introduced in 1959. Our results reveal differentiation within both S. tanganicae and L. miodon that is not explained by geography. Instead, this genetic differentiation is due to the presence of large sex-specific regions in the genomes of both species, but involving different polymorphic sites in each species. Our results therefore indicate rapidly evolving XY sex determination in the two species. Additionally, we found evidence of a large chromosomal rearrangement in L. miodon, creating two homokaryotypes and one heterokaryotype. We found all karyotypes throughout Lake Tanganyika, but the frequencies vary along a north-south gradient and differ substantially in the introduced Lake Kivu population. We do not find evidence for significant isolation by distance, even over the hundreds of kilometres covered by our sampling, but we do find shallow population structure.
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Affiliation(s)
- Julian Junker
- EAWAG Swiss Federal Institute of Aquatic Science and Technology, Kastanienbaum, Switzerland.,Division of Aquatic Ecology, Institute of Ecology & Evolution, University of Bern, Bern, Switzerland
| | - Jessica A Rick
- Department of Botany and Program in Ecology, University of Wyoming, Laramie, WY, USA
| | - Peter B McIntyre
- Department of Natural Resources, Cornell University, Ithaca, NY, USA
| | - Ismael Kimirei
- Tanzania Fisheries Research Institute (TAFIRI), Dar es Salaam, Tanzania
| | - Emmanuel A Sweke
- Tanzania Fisheries Research Institute (TAFIRI), Dar es Salaam, Tanzania.,Deep Sea Fishing Authority (DSFA), Zanzibar, Tanzania
| | - Julieth B Mosille
- Tanzania Fisheries Research Institute (TAFIRI), Dar es Salaam, Tanzania
| | - Bernhard Wehrli
- EAWAG Swiss Federal Institute of Aquatic Science and Technology, Kastanienbaum, Switzerland.,Institute of Biogeochemistry and Pollutant Dynamics, ETH Zurich, Zürich, Switzerland
| | - Christian Dinkel
- EAWAG Swiss Federal Institute of Aquatic Science and Technology, Kastanienbaum, Switzerland
| | - Salome Mwaiko
- EAWAG Swiss Federal Institute of Aquatic Science and Technology, Kastanienbaum, Switzerland.,Division of Aquatic Ecology, Institute of Ecology & Evolution, University of Bern, Bern, Switzerland
| | - Ole Seehausen
- EAWAG Swiss Federal Institute of Aquatic Science and Technology, Kastanienbaum, Switzerland.,Division of Aquatic Ecology, Institute of Ecology & Evolution, University of Bern, Bern, Switzerland
| | - Catherine E Wagner
- Department of Botany and Program in Ecology, University of Wyoming, Laramie, WY, USA
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Kmentová N, Bray RA, Koblmüller S, Artois T, De Keyzer ELR, Gelnar M, Vanhove MPM, Georgieva S. Uncharted digenean diversity in Lake Tanganyika: cryptogonimids (Digenea: Cryptogonimidae) infecting endemic lates perches (Actinopterygii: Latidae). Parasit Vectors 2020; 13:221. [PMID: 32357898 PMCID: PMC7195733 DOI: 10.1186/s13071-020-3913-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 01/24/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Lake Tanganyika is considered a biodiversity hotspot with exceptional species richness and level of endemism. Given the global importance of the lake in the field of evolutionary biology, the understudied status of its parasite fauna is surprising with a single digenean species reported to date. Although the most famous group within the lake's fish fauna are cichlids, the pelagic zone is occupied mainly by endemic species of clupeids (Actinopterygii: Clupeidae) and lates perches (Actinopterygii: Latidae, Lates Cuvier), which are an important commercial source for local fisheries. In this study, we focused on the lake's four lates perches and targeted their thus far unexplored endoparasitic digenean fauna. METHODS A total of 85 lates perches from four localities in Lake Tanganyika were examined. Cryptogonimid digeneans were studied by means of morphological and molecular characterisation. Partial sequences of the nuclear 28S rRNA gene and the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene were sequenced for a representative subset of the specimens recovered. Phylogenetic analyses were conducted at the family level under Bayesian inference. RESULTS Our integrative approach revealed the presence of six species within the family Cryptogonimidae Ward, 1917. Three out of the four species of Lates were found to be infected with at least one cryptogonimid species. Two out of the three reported genera are new to science. Low interspecific but high intraspecific phenotypic and genetic diversity was found among Neocladocystis spp. Phylogenetic inference based on partial 28S rDNA sequences revealed a sister group relationship for two of the newly erected genera and their close relatedness to the widely distributed genus Acanthostomum Looss, 1899. CONCLUSIONS The present study provides the first comprehensive characterisation of the digenean diversity in a fish family from Lake Tanganyika which will serve as a baseline for future explorations of the lake's digenean fauna. Our study highlights the importance of employing an integrative approach for revealing the diversity in this unique host-parasite system.
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Affiliation(s)
- Nikol Kmentová
- Department of Botany and Zoology, Faculty of Science, Masaryk University, Kotlářská 2, 611 37 Brno, Czech Republic
- Centre for Environmental Sciences, Research Group Zoology: Biodiversity & Toxicology, Hasselt University, Agoralaan Gebouw D, 3590 Diepenbeek, Belgium
- Laboratory of Biodiversity and Evolutionary Genomics, Department of Biology, KU Leuven, Ch. Deberiotstraat 32, 3000 Leuven, Belgium
| | - Rodney A. Bray
- Parasitic Worms Division, Department of Life Sciences, The Natural History Museum, Cromwell Road, London, SW7 5BD UK
| | - Stephan Koblmüller
- Institute of Biology, University of Graz, Universitätsplatz 2, 8010 Graz, Austria
| | - Tom Artois
- Centre for Environmental Sciences, Research Group Zoology: Biodiversity & Toxicology, Hasselt University, Agoralaan Gebouw D, 3590 Diepenbeek, Belgium
| | - Els Lea R. De Keyzer
- Laboratory of Biodiversity and Evolutionary Genomics, Department of Biology, KU Leuven, Ch. Deberiotstraat 32, 3000 Leuven, Belgium
| | - Milan Gelnar
- Department of Botany and Zoology, Faculty of Science, Masaryk University, Kotlářská 2, 611 37 Brno, Czech Republic
| | - Maarten P. M. Vanhove
- Department of Botany and Zoology, Faculty of Science, Masaryk University, Kotlářská 2, 611 37 Brno, Czech Republic
- Centre for Environmental Sciences, Research Group Zoology: Biodiversity & Toxicology, Hasselt University, Agoralaan Gebouw D, 3590 Diepenbeek, Belgium
- Laboratory of Biodiversity and Evolutionary Genomics, Department of Biology, KU Leuven, Ch. Deberiotstraat 32, 3000 Leuven, Belgium
- Zoology Unit, Finnish Museum of Natural History, University of Helsinki, P.O.Box 17, Helsinki, 00014 Finland
| | - Simona Georgieva
- Cavanilles Institute of Biodiversity and Evolutionary Biology, Science Park, University of Valencia, P.O. Box 46071, Valencia, Spain
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Weak population structure and recent demographic expansion of the monogenean parasite Kapentagyrus spp. infecting clupeid fishes of Lake Tanganyika, East Africa. Int J Parasitol 2020; 50:471-486. [PMID: 32277985 DOI: 10.1016/j.ijpara.2020.02.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Revised: 02/14/2020] [Accepted: 02/18/2020] [Indexed: 11/22/2022]
Abstract
Lake Tanganyika, East Africa, is the oldest and deepest African Great Lake and harbours one of the most diverse fish assemblages on earth. Two clupeid fishes, Limnothrissa miodon and Stolothrissa tanganicae, constitute a major part of the total fish catch, making them indispensable for local food security. Parasites have been proposed as indicators of stock structure in highly mobile pelagic hosts. We examined the monogeneans Kapentagyrus limnotrissae and Kapentagyrus tanganicanus (Dactylogyridae) infecting these clupeids to explore the parasites' lake-wide population structure and patterns of demographic history. Samples were collected at seven sites distributed across three sub-basins of the lake. Intraspecific morphological variation of the monogeneans (n = 380) was analysed using morphometrics and geomorphometrics of sclerotised structures. Genetic population structure of both parasite species (n = 246) was assessed based on a 415 bp fragment of the mitochondrial cytochrome c oxidase subunit I (COI) gene. Overall, we observed a lack of clear geographical morphological differentiation in both parasites along a north-south axis. This lack of geographical population structure was also reflected by a large proportion of shared haplotypes, and a pattern of seemingly unrestricted gene flow between populations. Significant morphological and genetic differentiation between some populations might reflect temporal differentiation rather than geographical isolation. Overall, the shallow population structure of both species of Kapentagyrus reflects the near-panmictic population structure of both host species as previously reported. Morphological differences related to host species identity of K. tanganicanus were consistent with incipient speciation at the genetic level. Both parasite species experienced a recent demographic expansion, which might be linked to paleohydrological events. Finally, interspecific hybridisation was found in Kapentagyrus, representing the first case in dactylogyrid monogeneans.
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