If you can't get the answer from the very knowledgable people here, here are some sites that I think have good info - I can't guarantee that they are all 100% accurate as sites have been known to contain errors and typos so it's always best to check with people here for their actual experiences.
FishProfiles.com - this has profiles for a lot of freshwater fish with size, behaviour, feeding and breeding info.
Loaches Online - this has a lot of information about many different species of loach.
Google is always a good way to find other pages of information about specific fish.