Tiny Jellyfish?

 This hobby is not short of "what is that" or "what kind of" questions. From the first moments spending time with your tank as it begins it cycle til you move on from the hobby, there will be moments of awe. 

Tonight, 2 small jellyfish with no visible tentacles. Unsure where they came from, but only a few possibilities. 

1. They were hitchhikers in some of the water from a frag bought week ago. 

2. They were in the "clean" water during a water change.

3. They've been there all along and were hard to spot this whole time.