I find the listing of fresh water fishes found in Thailand (including loaches of course) most interesting:
http://fish.mongabay.com/data/Thailand.htm
Click on the Scientific Name of each individual fish and you will get a description of their natural habitat, what they feed on, etc. Pangio Kuhlii lives in hill streams too!
Hope you will find this helpful.
Am sad that one of my favourite fish, the Redtail (Sharkminnow) Blackshark (Epalzeorhynchos Bicolor), is extinct in the wild
