The Atlas Massif separates a northern and a southern mitochondrial haplotype group of North African water frogs Pelophylax saharicus (Anura: Ranidae) in Morocco.

We assessed the genetic variation of 47 Moroccan populations of the North African water frog (Pelophylax saharicus) using partial sequences of the mitochondrial cytochrome oxidase subunit I gene (COI). All 239 samples belonged to the main haplotype clade previously identified from Morocco, with no haplotypes of the Algerian/Tunisian clades among our samples. Altogether 40 haplotypes were found, with a maximum of 13 mutational steps between them. Two weakly divergent haplogroups separated by a minimum of six mutational steps were distributed (i) in the Anti-Atlas and the Sahara (south of the High Atlas Mountains) versus (ii) in the Middle Atlas, the High Atlas, and in the Rif area north of the Atlas Massif. Haplotypes of the northern haplogroup were found at the southernmost locality, which might be due to human translocation, and co-occurrence of the two haplogroups was recorded at three sites within the range of the northern haplogroup. [ABSTRACT FROM AUTHOR]