If the male becomes too aggressive, she avoids the encounter, sending him into a frenzy. This is the reason two females are present in the breeding aquarium. Although the male can never be considered gentle in his breeding behavior, he soon calms down. With fin-stroking and bumpings, the pair align at the upper part of the spawning map, where quivering bodies produce an egg. The spawning mop should be removed, wrung out, and examined for eggs every other day.
Mummichogs are avid spawn-eaters.
They can be easily removed from the spawning mop with your fingers. I placed the eggs in a plastic margarine dish filled with water from the spawning aquarium and added enough acriflavine to color the water yellow. The acriflavine is a fungicide which protects the eggs for the first two days. I placed the covered margarine dish on top of the breeding aquarium to incubate the eggs. Replacement of the dish on the breeding aquarium and recleaning every two or three days is the norm.