The red-finned shark is also called rainbow shark? Black with all red fins? I had one of those for years when I was a kid. A robust fish that does not like members of its own species or related species. One to a tank, unless you have a very big tank. I think they are fin nippers.
Red-tailed sharks I've never bought as they always appear to be at death's door at the lfs
. Listless, having trouble controlling bouyancy, just not looking like a very healthy fish. Most of the pet shops in my area (New port Richey, FL) are on par with WalMart so their fish are horrible. Don't suppose anybody knows of a good lfs
in this area?