I bought a 15" Juruense and when I got him he didnt have any streamers. They grew back quickly....and I mean quick at like 1/2" a day. The thing is that even though it grew 1/2" in lenght it was VERY thin and most of the time fell off with only the thickest part remaining. It continued to grow that way though...long thin, fall off with thickest remaining, more long thin, ect....
Anyway at one point he did develope a fork but it fell off and the fork hasnt grown back. It continued to grow in lenght. Ive had him for a month and half now and he went from no streamers at all to 10" thick beautiful streamers!
Also I forgot to mention that since the new growth is so thin it tends to wave around alot more then the thicker parts and they will litterally get knotted. When this happens it usually falls off and starts over.
Hope my novel helps!