Gerlach et al. (2012; Mar Ecol Prog Ser 450:281-283) argue that temporal instability in patterns of cryptic genetic differentiation in Doryteuthis pealeii, resulting from sampling of family groups, is the most likely explanation for differences in patterns of genetic differentiation presented in Buresch et al. (2006) and Shaw et al. (2010). We agree that temporal genetic patchiness might be an explanation, but disagree that cohesive and genetically differentiated family groups are the cause. We conclude that currently there is not enough evidence for temporally stable population differentiation, explained by a feasible biological/physical mechanism, to support management of the species as anything other than single genetic stocks across large geographical regions of the NW Atlantic. Further study of this species is warranted to understand the factors generating temporal genetic changes.