I agree with Jim... this should not be such an important topic of discussion. People are getting way too picky in here about little details like how the fins are rendered. Look, 3d rendering has always involved taking shortcuts and performing "tricks" to create believable animation while maintaining a good framerate.
For example, run your favorite 3-D racing game, and take a close look at the trees on the side of the road. They are flat planes. But overall they contribute to a believable environment, unless you sit there and stare at one of them. You want more realistic trees? Then prepare to buy a GeForce10 and drive at 5 fps.
I'm not saying that making 'constructive' comments is a bad thing. But let's not go overboard. And let's not constantly remind Jim of the little compromises that he's had to make to get this incredible screen saver to work. He's well aware of them. He's a perfectionist more than any of us.
If you need to remind yourself just how great this screensaver is, go hunt around the internet, find the next best aquarium screensaver, load it up, and see how long you can tolerate it. You'll be back to Jim's masterpiece in no time.
Personally, I'd rather Jim concentrate on making new creatures than spending the next 6 months perfecting the lionfish. It's pretty awesome already...and would look even better next to a coral shrimp (hint hint).
Just my $0.02
