The mangrove killifish is unique among vertebrates due to its self-fertilizing mode of reproduction. Here, we describe a three generation forward genetic screen to identify zygotic mutants which show phenotypes that disrupt early embryonic development. We treated parental fish (P; N = 34) with increasing doses of N-Ethyl-N-Nitrosurea (ENU) which induces point mutations in the germ-line in other model organisms. These P fish were self-crossed, producing 7,350 F1 progeny. 1,334 F1 fish were hatched and raised to maturity (18%). From these F1 fish, 284 were allowed to self-cross (284 genomes) and their F2 offspring were observed during embryogenesis for mutant phenotypes disrupting early development (zygotic mutants). We are currently observing these zygotic mutants into the F3 generation. Documented here are the types and frequencies of these zygotic mutants in our ongoing screen.