they look like what i have at my store now... which i randomly ordered one day not knowing but the name i ordered were "Whiptail catfish"...latin name was like lip..lai..something weird
The one posted by Sarcosuschus was a Pseudogastromyzon cheni by the looks of the pic. It is still one of the hillstream loach species discovered along with Beaufortia, Gastromyzon, Homaloptera, etc.
it might of been a flathead platycephalus fuscus. although the scientific name there are about 5 different species that i know of so dont use the scientific name to find out but here is a pic if it has simalar body shape it would be this. buy the way thoose chineese butterfly loach i had one and i must say they are a beautiful little thing.
once again dont use colours as in indicator as there are many different species of flathead.