So I've got a 45 gal. tall (20"X18"X30"tall) with lots of vertical rock work and caves. I've housed a dozen paracyp nigripinnis (3 male, 9 female) for almost a year now after picking them up at approx. 2" length. I'd assume they're mature as the males are colouring up and the females are 'bulking up', however aside from occasional fin displays and quivering, I've got zero love in the tank. No obvious dominant male, no pairing up, no failed spawns. So, my question is, is the tank footprint too small? It's not like they're swimming in circles, and there's plenty of refuge. Any opinions are welcome.