I know what the egg tube looks like. There have been definite males and females. They have fertilized them, as they will be a yellow green color, and though they constantly fanned them (they wouldn't even leave them for food), and i added Methylene Blue and another fungus inhibitor, they would still go bad. I was under the assumption that maybe it was the high pH that they live in. But then, i had a pair of firemouths breed recently. So I am thinking that may not be true.