I studied the population genetic structure of abyssal grenadier: Coryphaenoides armatus and Coryphaenoides yaquinae of the Pacific and Atlantic Ocean basins, testing the hypothesis that population genetic structure is detectable by microsatellite allele analysis. I determined allele frequencies at six microsatellite loci, assessing genetic structure using Jost’s D_est.

Pacific versus Atlantic C. armatus yielded D_est comparable to Pacific C. armatus caught 170 km apart. Given the subspecies designation of North Pacific versus Atlantic C. armatus, it was unexpected that D_est of the former comparison would approximate the latter; or that the latter would be significant at all. Pacific fish may exhibit depth-driven genetic structure. Coryphaenoides yaquinae of the eastern Pacific, CCZ, and central North Pacific were also compared. Only the CCZ versus eastern Pacific yielded unambiguously significant D_est. Similar values among D_est in both species suggest horizontal distances among sampling sites are not the principal driver of population genetic structure.