2 of my first fish were jewels. I lucked in with a breeding pair. They seemed to be passive fish for about 4 - 6 months, then they became territorial. The stayed in a cave only coming out to eat and chace off any other fish regardless of size.
Around this same time the red one of the 2, started laying eggs which she did a few times, but I never saw any fry. Not sure if they died, were eaten, or never hatched.
But I can say that they only liked each other and were extreamly aggresive toward any others invading their terrotory