Molecular Identification of an Invasive Sarotherodon Species from the Atchakpa Freshwater Reservoir (Oueme River Basin, Benin) and Comparison within S. melanotheron Using COI Markers

The Atchakpa freshwater reservoir (Oueme Basin, Benin) was found to harbour an unexpected population of a cichlid species that was presumed to be Sarotherodon melanotheron. This species became dominant in the reservoir and became the main fisheries target species. We applied DNA barcoding to identify this population. Besides specimens from the reservoir, we also sequenced S. melanotheron from its native range in Benin at the lower Oueme and So Rivers, and from Lake Nokoue, and Porto-Novo Lagoon. High sequence similarity indicated that all specimens were conspecific. Hence, we cannot exclude that a natural range extension led to the presence of the species in the reservoir. A comparison with sequences from NCBI GenBank confirmed that all samples belonged to the subspecies S. m. melanotheron, which is native to Benin. This comparison also showed that this subspecies was previously introduced in the Philippines. We call for further studies to investigate the socioeconomic, ecological and environmental impacts of the species in the Atchakpa reservoir.

Automated summary

The study revealed that the population of Sarotherodon melanotheron in the Atchakpa reservoir may have resulted from a natural range extension within Benin. The subspecies S. m. melanotheron has also been previously introduced in the Philippines. Further research is necessary to investigate the socioeconomic, ecological, and environmental impacts of this species in the reservoir.