Genetic diversity and population structure of selected lacustrine and riverine populations of African catfish, Clarias gariepinus (Burchell, 1822), in Kenya
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Date
2021
Journal Title
Journal ISSN
Volume Title
Publisher
Journal of Applied Ichthyology
Abstract
Determining the genetic characteristics of natural fish stocks is useful for conservation
and aquaculture programs. For African catfish, Clarias gariepinus, genetic characterization
could help identify populations suitable as brood stock for culture, and
those in need of conservation. This study determined the genetic diversity, population
structure, and demographic history of C. gariepinus from Lakes Victoria (LV),
Kenyatta (LKE), Kamnarok (LKA), and Rivers Nyando (NR), Tana (TR) and Sosiani (SR)
in Kenya. Using 128 DNA sequences of D-loop
control region, 34 haplotypes were
recovered, of which 79.4% were singletons. Only 7 haplotypes were shared between
sites, implying little gene flow between sites. Number of haplotypes was highest in
LKE and NR populations and lowest in SR. Haplotype diversity was highest in LV,
and lowest in SR, while, nucleotide diversity was highest in LKA and lowest in LV.
Phylogenetic analyses revealed five clusters: Lakes Victoria, Kamnarok and Kenyatta,
and Rivers Tana and Nyando, from both maximum likelihood tree and minimum spanning
network. This, together with significant FST values among the sites imply population
differentiation. Mismatch distributions were multi-modal
in LKA, LKE, NR and
TR, signifying demographic equilibria. Neutrality tests Tajima`s D values for the sampled
populations were negative and significantly different, suggesting stable populations.
These results show the existence of genetically distinct populations of C.
gariepinus that require spatially explicit management actions such as reducing fishing
pressure, pollution, minimizing habitat destruction and fragmentation for sustainable
utilisation of stocks.
Description
Keywords
Clarias gariepinus, Genetic differentiation, Haplotypes, Mitochondrial DNA control region, Multi-modal distributions
Citation
Alal, G. W., Barasa, J. E., Chemoiwa, E. J., Kaunda‐Arara, B., Akoll, P., & Masembe, C. (2021). Genetic diversity and population structure of selected lacustrine and riverine populations of African catfish, Clarias gariepinus (Burchell, 1822), in Kenya. Journal of Applied Ichthyology, 37(3), 427-438. DOI: 10.1111/jai.14167