Genetic Diversity in the mtDNA control region and population structure of Chrysichthys nigrodigitatus from selected Nigerian rivers: Implications for conservation and aquaculture

  • Sylvanus A. Nwafili
  • Tian-Xiang Gao
Keywords: Chrysichthys nigrodigitatus, mtDNA control region, Niger Delta, Niger River, Lagos Lagoon, Shiroro Lake


The genetic diversity and population structure of Chrysichthys nigrodigitatus were evaluated using a 443 base pair fragment of the mitochondrial control region. Among the eight populations collected comprising 129 individuals, a total of 89 polymorphic sites defined 57 distinct haplotypes. The mean haplotype diversity and nucleotide diversity of the eight populations were 0.966±0.006 and 0.0359±0.004, respectively. Analysis of molecular variance showed significant genetic differentiation among the eight populations (FST =0.34; P < 0.01). The present results revealed that C. nigrodigitatus populations had a high level of genetic diversity and distinct population structures. We report the existence of two monophyletic matrilineal lineages with mean genetic distance of 10.5% between them. Non-significant negative Tajima’s D and Fu’s Fs for more than half the populations suggests that the wild populations of C. nigrodigitatus underwent a recent population expansion, although a weak one since the late Pleistocene.


S.A. Nwafili [+]
Department of Fisheries, Faculty of Agriculture
University of Port Harcourt, Nigeria
T. X. Gao
Laboratory of Mariculture, Ocean University of China,
266003 Qingdao, PR China