What are the transparent strands in this salad? What are the transparent, irregularly winding strands at the bottom of the following picture? They can obviously be had cold together with salad. They are very crispy.

They are much firmer and crisper than any "pudding jelly" I have met. They do not seem to be made in a mould but have a more "natural" shape.



I had this in Thailand and when I ask what it is, people have told me wun (jelly) and buk (which I don't know what it is). I am not sure this is correct.
(The staff preparing the salad buffet called it "buk", like English "book".)

What is it and how is it made?

In China I had somewhat similar food but warm and not completely transparent. I was told that was jellyfish. The only transparent things I come to think of are jellyfish (cut in strips) and konnyaku. Could this maybe be jellyfish?

Two more pictures:
https://imagizer.imageshack.us/v2/320xq90/r/908/B0O23n.jpg
https://imagizer.imageshack.us/v2/320xq90/r/537/3Sc643.jpg
I think what you are looking for is kelp noodles. They are considered a type of glass noodle. They can be eaten raw or cooked in other dishes. In their raw state they are crunchy. Please see this link for a picture and some info.

Hope this helps! :)