| Summary: | The mitogenome of an endemic catfish <i>Clarias camerunensis</i> was determined from the Cameroon water. This circular mitogenome was 16,511 bp in length and comprised 13 protein-coding genes, 2 ribosomal RNAs, 22 transfer RNAs, and a single AT-rich control region. The heavy strand accommodates 28 genes, whereas the light strand is constituted by <i>ND6</i> and eight transfer RNA (tRNA) genes. The <i>C. camerunensis</i> mitochondrial genome is AT biased (56.89%), as showcased in other <i>Clarias</i> species. The comparative analyses revealed that most of the <i>Clarias</i> species have 6 overlapping and 11 intergenic spacer regions. Most of the PCGs were initiated and terminated with the ATG start codon and TAA stop codon, respectively. The tRNAs of <i>C. camerunensis</i> folded into the distinctive cloverleaf secondary structure, except <i>trnS1</i>. The placement of the conserved domains in the control region was similar in all the <i>Clarias</i> species with highly variable nucleotides in CSB-I. Both maximum likelihood and Bayesian-based matrilineal phylogenies distinctly separated all <i>Clarias</i> species into five clades on the basis of their known distributions (South China, Sundaland, Indochina, India, and Africa). The TimeTree analysis revealed that the two major clades (Indo-Africa and Asia) of <i>Clarias</i> species might have diverged during the Paleogene (≈28.66 MYA). Our findings revealed the separation of Indian species (<i>C. dussumieri</i>) and African species (<i>C. camerunensis</i> and <i>Clarias gariepinus</i>) took place during the Paleogene, as well as the South Chinese species (<i>Clarias fuscus</i>) and Sundaland species (<i>Clarias batrachus</i>) splits from the Indochinese species (<i>Clarias macrocephalus</i>) during the Neogene through independent colonization. This pattern of biotic relationships highlights the influence of topography and geological events in determining the evolutionary history of <i>Clarias</i> species. The enrichment of mitogenomic data and multiple nuclear loci from their native range or type locality will confirm the true diversification of <i>Clarias</i> species in African and Asian countries.
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