We're they adults or juvies when you bought them? Is it possible they just aren't sexually mature yet?
I have a black calvus pair that just had their first viable clutch of fry. The male I raised myself and he is about 18 months old now. He has been with the female in my mixed African display for easy 8 months and had their 1st spawn 3 weeks ago. I didn't even know they were a pair. They paid absolutely no attention to one another until a couple of days before the spawn. The mail help guard the shell for about 5 days and then just moved back over to the other side of the 125 and left the female to herself with the fry. Once the fry were free swimming the female would even push the male away as though he was a threat...
