They are smaller but the thing that still makes them a 10 gallon fish is that they need at least 6 to school with. They are so small and timid that bigger fish frighten them unless they are with a good sized grouping of their own kind and I have seen betta naughties frighten them to death. No they are not suitable for smaller tanks, I am sorry to say. (personal experience,

) Also in aquariums, the males will almost reach an inch and females will grow slightly over an inch in length. (resourced from
Identifying Corydoradinae Catfish written by Ian A.M. Fuller & Hans-Georg Evers - copyrighted in June 2005) I am thrilled and happy beyond words to own a brand new signed copy of it that I got from the author himself.
Rose