I think the two cyprinids near the front are Probarbus jullieni, and there's another barb at back which I think must be a tinfoil barb. I was looking at the catfish so didn't really pay any attention to the barbs at the time. There are also quite a lot of albino plecostomus in there as well of course.
I looked at those some days ago and remain puzzled. Not even sure about the family! Yes, the others are tinfoil barb + Probarbus. It seems all Probarbus frequently are labelled as P. jullieni, but the two other species in the genus, which were only described in 1992, are quite similar in coloration (especially P. labeamajor), native to the same region and present in fisheries too. Some info in this PDF. Note that longitudinal stribe count is from lateral line scale to dorsal fin.
I was back at the market today. I'd had the name "wood catfish" running around in my head and I asked the girl at this shop what species they were. She didn't speak any English but she showed me in her book. They are Trachelyopterus fischeri (syn. Parauchenipterus). I don't know if this is common to all related species but the males have a long bent dorsal spine, giving them that funny-shaped dorsal fin (there are some visible in the photo).
What I really like about the Fish Market at Chatuchak is that the people running and working in the stalls and shops really seem to be proper knowledgeable animal people, unlike the sellers of the birds and small mammals who seem more like animal abusers than animal lovers.
