Nope. Fish grow throughout their entire lifespan, until near the end, when the shrink a little bit. They have a range, and if the tank is big enough to support good water quality, then they are stunted or die.

Nate, if you're really interested in natives, then PM me. We can talk over the phone about it. Your best bet, get proper permits to collect natives, and target the pygmy sunfish species.

I'll send you a message when I'm ready to start haha. In Pa, you can collect any native species as long as you have a fishing license (still have to follow creel and size limits) and they aren't endangered. I think there are special regulations on Pike, but I'm not going for them. There are also regulations on the nets you can use (size and type limits). I hear NY is much more strict on obtaining fish.

I did my collecting in the NJ Pine Barrons.

I'm surprised NJ has live fish I kid, I kid! I was fishing in the Juniata a few months ago and walked through a tiny mountain runoff that went into the river... Sitting right in front of that run off, half of it's body out of the water, was a 6" bowfin. I almost touched the darn thing and could have probably caught it if I wanted... They probably get too big for what I want to build though...

I have an aquarium with 2 largemouths in it and a plecostomus to keep the glass clean.