I hatched my banded cat shark in a 45 gallon aquarium. I quickly transfered him (he DID have claspers) to my 125 gallon. He could have stayed in the 45 for a bit longer, but I happened to stumble on a used 125 for cheap. I'd say the shark grew to about 11-12 inches in about a period of 6 months. I've heard of a number of people keeping these sharks long-term in a 180 or so, but I can't vouch for the CAPTIVE raised size of any adults. I eventually turned my shark over to someone who a 1000 tank that was maintained by the LFS that I was part-timing at.
I will offer this advice: IF YOU ARE LOOKING FOR EXCITING PREDATORY BEHAVIOR CAT SHARKS ARE NOT A GOOD CHOICE. I was ofcourse very excited when my egg hatched after babying an egg for three months. And I was thouroughly stoked getting it to eat, and watching it grow. However, the shark spent most of the day in ONE place. Lilterally. The shark never hunted. I literally had to skewer a piece of meat and put it under his nose, or very close to. I fact was that cat sharks are nocturnal, and well, I'm not. So it wasn't a good fit for me. I finally decided to let the shark go when I was forced to introduce my Blue Angel back into the tank. The angel was litterally trying to peck out the sharks eyes. A very accurate and decided peck. At this point, it was one or the other, and well.....