i just noticed that the end of my male motoro's tail had a piece missing and its white at the end...... its tail rot right ? the only thing that i would think that would bite him would be a 9in red tail tiger catfish.... idk u tell me
Could definately be a cat or some other bottom feeder gnawing on the tail. Hard to tell from pics. This is common with rays in community tank setups. Like stated above, keep up with the water changes and add a bit of aquarium salt to the tank