With proper care they can get massive, 10”+. I’ve seen altifrons at an LFS that were raised by one of the employees in a 300 gallon tank, and they were almost as long as my forearm. Before that I thought the size listed for them was a myth. I don’t know how long it takes to attain that, and if all abalios/altifrons will. I’m assuming they may average out to about 8”.