a) The aquarium is 27g with the footprint of a 33g (not a 33g with the footprint of a 40g).
b) The size of the remaining Tang has repeatedly been referenced as 3cm and yet if you look at this
picture of the tank when it had 2 Tangs and do a little math to figure out the scale you get the following (17" monitor, blah, blah, blah the specifics don't really matter because everything is kept to scale anyway.): On my monitor the tank in the picture is 81mm long, and the smallest of the 2 Tangs (which is not parallel to the front pane of glass and is actually turned sideways somewhat) is 6mm long. Assuming the tank is indeed 36" long, 6/81 x 36" equals a 2-2/3" (or 6.8cm) Tang. Do either of the fish in the picture seriously look like they're 3% of the length of the tank?
c) Consider the observations made by Richard Harker: Upon setting up his newest aquarium (the really long one - I forget how long it was exactly - something like 12 or 15 feet) he noted that his Yellow Tangs began to exhibit much more natural behavior (swimming patterns in particular) than they had in smaller aquariums. Granted, the above case is in reference to a Yellow Tang and not a Regal Tang, but Harker's observations clearly indicate that "eliminating/changing" the aforementioned "4 needs" had a limited effect on "natural need for space", and that the desire for space was intrinsic and, once fulfilled, facilitated significant changes in behavior.
[ 19 September 2002, 16:23: Message edited by: Canadian ]