North African sharptooth catfish Clarias gariepinus In silico analyses for genetic expansion of a peculiarly successful catfish species in and out of its African homelands

The African sharptooth catfish Clarias gariepinus originated from Africa, but its sturdiness and resistance to different environmental conditions enabled it to spread to almost all continents of the world. To develop effective conservation strategies for C. gariepinus, the connection patterns of its geographically related and isolated strains should be precisely described. For this purpose, 65 sequences for cytochrome oxidase subunit 1 (CO1) mitochondrial gene were retrieved from GenBank database. Common and unique haplotypes, average numbers of nucleotide substitutions (Dxy), fixation indices (FST), neutrality and expansion, phylogeny, and haplotype network analyses were all identified. 13 different haplotypes were found, most of which are related to an African haplotype mainly found in Nigeria. Other African, Asian, and South American haplotypes were detected, with the South American and some Asian haplotypes showing the greatest diversion from the main African one. The Nigerian population of C. gariepinus seems to be the most rapidly expanding one, due to the highest frequency of singletone haplotypes among all studied populations. Our results agreed with the knowledge about the world-wide propagation of C. gariepinus recorded in the Food and Agriculture Organization introduced aquatic species database and other related reports, what may confirm the effectiveness of such molecular markers and bioinformatic tools for tracking the origin and movement of the C. gariepinus out of Africa.