There aren't actually that many that can thrive in something that small. The only things that spring to mind are hillstream loaches and bulldog plecs, and even then you're pushing things. None of the shoaling stream-type species (zebra danios, WCMMs) would want to be in something that small.
BTW, if you post the same question in different places, things get confusing as to who said what in which thread. Therefore I have moved this thread into this section, and removed the other one.