Well, I guess it is possible to sex the little critters, but I can't imagine the killifish care. Mine don't. But, to answer your question (indirectly), goto -> http://sdb.bio.purdue.edu/fly/aimain/1aahome.htm
See also http://ceolas.org/fly/
> First are Fruit Flies asexual or bisexual?
> Second if asexual as I suspect are they impregnated for life
> with one
> copulation as the Honey Bee is?
Survey Research Laboratory
Arizona State University