What size tank do you have, what size did you buy it at, has the fish been vented because it may be a female- (I saw a 13 inch female that was mean as all get out and even had a small hump). And what are you feeding it ? Also between the two cichlids who is the current dominate fish ?
Considering that red devils are actually mixed between Midas and Red devil (unless you purchased a proven A. labiatus from an importer or can trace its lineage), it may not develop a significant hump. Here's a proven red devil (courtesy of Jeff Rapps TUIC) with a hump
its in a 29 gal for now. he was only an inch long when i bought him. i feed him cichlid gold & tubiflex worms & anything hell eat.
If you've kept that inch long red devil in a 29 for a year, then you've probably stunted it quite a while. I suggest you get atleast a 75 gallon tank for the guy.
As the other guy stated a larger tank will lead to more growth and subsequently a larger hump. To give you a more direct answer though, it all comes down to genetics.. be patient give it plenty of room, high quality food and I’m sure you will be pleased ?
