Lampeyes are most un-killi like in their behaviour and habits being fast swimming schooling fish. That's because they are Poecilids, that is these particular egg laying tooth carps are more closely related to live bearing tooth carps - guppies, platies and the like - than other killifish. In fact Lampeyes and Livebearers are both member of family Poecilidae. Technically this makes livebearers killifish.