I used to have one. I bought him at like an 1". It was the most active one in the tank. As it grew larger and larger (very quickly, I might add) I realized that it was blind and born without eyes. It was a cool fish none the less. I had to keep it alone though to ensure it was getting food. It grew quite large and even for being blind, it would be able to hunt down feeders that I gave it once or twice a year. It went from 1" to 8" in 6 months. I wanted to put him in the Big Boy Tank, but since it was blind, I didn't want to risk it nipping at anything that moved or not eating enough. I was doing a water change one day and moved it into a tub while I was cleaning it's tank. It just went into shock or something. By the time I finished cleaning, it died on me 
It was about 2 years old. He didn't get to big, just because I had it in a 20 gallon tank. So I can't really tell you about agression with other fish, but I can tell you they grow quickly and even though it was blind, it was kind of personable. It would feed from my hand and stroke itself against my hand. I believe that they grow to 24" and I hear they're pretty aggressive feeders. I've seen tanks with these guys in there with other fish and they seem to be find as long as they have a hiding place.
It was about 2 years old. He didn't get to big, just because I had it in a 20 gallon tank. So I can't really tell you about agression with other fish, but I can tell you they grow quickly and even though it was blind, it was kind of personable. It would feed from my hand and stroke itself against my hand. I believe that they grow to 24" and I hear they're pretty aggressive feeders. I've seen tanks with these guys in there with other fish and they seem to be find as long as they have a hiding place.
Unbelievable.
