I think is a good thing to ask questions when you want to know. and the fishy style popped in my head after having a smartass conversation on facebook and reading this. I could not resist saying it. lol
yes I love using thread as a rib when I am looking for a flat rib style fly. I don't like using tinsel that much and wire gives it a bumpy look. when I can I use thread for a rib. it gives a cool look and is everyday material.
if you have any other questions on it just ask no worries.
That is a very nice modern, steelhead hairwing-wet syle fly that uses pheasant rump instead of hair for the wing. One can use pheasant rump, hair, marabou, or even Krystal Flash or Flashabou for the wing on this style of fly. Heck, you could made the body from floss as you did here, chenile, Estaz (and its relatives), dubbing, wrapped quill (hackle quill or turkey or goose quill that has been split and scraped to get the pith out of it, yarn, Swiss Straw, or pretty much anything else.