That is really weird. Got a mayan the other day and woke up this morning to find a chunk of his tailing missing as well. I have him in there with a JD and Salvini.
it really depends on how long you want to have that community in your tank. If you are satisfied with having that arrangement for 2-3 months then it will be fine but eventually the mayan will kill anything in its space.
If you added HIM to THEIR tank, he's bound to get his ass beat the first night, especially if you have very many cons. They're already comfortable, he's not. Give him a few days, it'll be the other way around. Besides, tail nips are cowardly shots anyway . What's the size comparison?
i grew out 4 from one inch to 5 inches and mine didnt start showing aggression until they were 5 inches and it was little at that. i think normally they dont get real mean until there around 7 or bigger then they can be down right nasty toward other cichlids.
The Mayan I had beat the hell out of every other fish in my tanks and killed my big male Salvini (who WAS the boss of the tank.) The Mayan shredded the Sal to death, almost de-scaled my JD, tore apart a breeding pair of cons, and beat my male Nic (who was bigger than the Mayan) up so bad the Nic almost lost his eye.
The Mayan I had beat the hell out of every other fish in my tanks and killed my big male Salvini (who WAS the boss of the tank.) The Mayan shredded the Sal to death, almost de-scaled my JD, tore apart a breeding pair of cons, and beat my male Nic (who was bigger than the Mayan) up so bad the Nic almost lost his eye.