The vast majority of inherited biological information is hard-coded in DNA sequence; however, epigenetic modification provides an additional conduit for intergenerational transmission of molecular memory. In mammals, inheritance of epigenetic memory in the form of DNA methylation is largely prevented by extensive erasure and reprogramming early in germline formation. We recently discovered that, unlike mammals, the germline of zebrafish does not undergo genome-wide erasure of DNA methylation during development. The significance of epigenetic memory preservation and its consequences for basic biological processes such as sex determination, is discussed.