Complete mitogenome sequences of smooth hammerhead sharks, Sphyrna zygaena, from the eastern and western Atlantic.

We report the first mitogenome sequences of the circumglobally distributed, highly mobile, smooth hammerhead shark, Sphyrna zygaena, from the eastern and western Atlantic. Both genomes were 16,729 bp long with 13 protein-coding genes, two rRNAs, 22 tRNAs and a non-coding control region. The two Atlantic shark sequences differ from each other by 13 SNPs, and by 43 and 44 SNPs from the published mitogenome of an S. zygaena specimen from the eastern Pacific Ocean. The cross-Atlantic mitogenome sequences reported here provide a resource to assist with population genetics studies of this widely exploited species of conservation concern.