Population genetics of freshwater stingray require investigation to confirm DNA contamination: Reply to Alshari et al. (2023)

Alshari et al. (2023; Endang Species Res 50:311-313) were able to collect 3 Fluvitrygon kittipongi specimens from the Pahang River, which were not available to us at the time of our study (Lim & Then 2022; Endang Species Res 48:43-50). The cytochrome c oxidase I (COI) sequences (or haplotypes) of these 3 stingrays were identical to each other but differed from the haplotypes of our Perak River specimens. The result of 100% similarity between COI sequences of our Perak River rays and the eDNA water samples isolated from Pahang River in our study was suggested by Alshari et al. (2023) as DNA contamination in our study, which is plausible. However, further population genetics studies would be necessary to ascertain that the Perak River haplotype does not occur in stingrays of the Pahang River.