Plumbing ...
No plumbing? Just fill'r up?! 
A huge dehumidifier and/or air exchanger is one critical thing I think is missing from the list ATM.
I didn't think a dehumidifier or air exchanger would be needed if the room had a seperate furnace with its own make up air. After thinking about it, some sort of dehumidification would be needed during the summer months when the furnace isn't active much.
A drop ceiling is a must!! Heat will rise quickly and a drop ceiling will help keep it in the basement.
I assumed a finished ceiling of some kind, but it can't drop too much unless the its 15' high.
Add a circulating fan (to limit temperature stratification) and waterproofing to the walls and you can (dare I say it...) RULE THE WORLD!
Mike
During winter months when the furnace is frequently active - if the air distribution and air returns are designed properly there should be a need to circulate it any more. Correct? In summer months when the furnace doesn't activate much then yes it probably would be needed.
Regarding the walls I'm debating between green board finished with gas station bathroom wall material or plywood with a water proof paint. I like the idea of plywood only because I like to mount things in periodic locations without having to worry about stud location. (How much you want to bet Blair uses the last sentence as his signature now?) Probably leaning towards green board.
If I had my perfect fishroom, it wouldn't be in my basement. I would have it attached to my garage so it was on the first floor. That way, I could have a "fire wall" that would separate it from the rest of the house to eliminate the potential for moisture problems.
For a basement fishroom, I would recommend the following substitutions or additions to what you have listed:
I think I would go with greenboard (moisture resistant drywall like you would use in a bathroom) as opposed to plywood. Mostly because once whatever you paint it with to seal it is breached, you'll see the plywood start swelling up like crazy.
I would also drywall the ceiling as well to help keep in moisture. Insulating the walls and ceiling are a good investment in keeping heat in the room.
I agree with Ron, an air exchanger is a good way to bring in fresh air, lower humidity, and keep most of your heated air.
For electrical, I would run conduit and boxes as opposed to in wall plugs (again, to help keep the room sealed up better).
LED lighting the length of each aisle.
For plumbing, I would have a tankless hot water heater.
I would also have each of my tanks drilled, with a central drainage system to eliminate having to carry buckets or pump water. For filling tanks, I would have a piping system around the room where there would be a fill pipe for each tank. All you would have to do is turn a valve and the tank would fill to either the top of a standpipe or bulkhead. I would also have a way of determining the temperature of the clean water (either some type of mixing valve or automated temp sensor) to ensure the water is the correct temp when refilling.
A sink and work table with good lighting is a must.
A stereo system is another excellent addition. My fish spawn like crazy to 80's hair bands and Metallica 
I don't want to have to go outside to get to my fishroom. I would end up neglecting them too much. An addition to the house is a possibility on the right house - most of the time it doesn't seem realistic though. This is way I'm looking at the basement fishroom.
I agree with your concerns on the plywood, which has me re-thinking that on the walls.
I planned on a finished ceiling, just haven't gotten the time to fill that part in.
When you say " I would run conduit and boxes as opposed to in wall plugs" are you referring to running the conduit and mounting the boxes on the surface of the walls and ceilings? This is for limiting air transfer through the wall?
Why LED lighting? Benefits, etc.?
I agree auto water changing is a must! Not sure of the best method though. Constant drip to all tanks? Water change controlled with sprinkler system controls? Supply water temp issues?
Sink, bench / desk, storage cabinets, and refrig / freezer are must haves as well.
Stereo would need to be for Liza and Barry though! LOL.