ID Please

[WhatCouldGoWrong71]

In the last 48 hours the only things that is different is that I had to replenish some CUC and I dosed iron. I added:
- Trochus Snails, Florida Ceriths, Nassarius vibex, Astraea Snails, Dwarf Ceriths, Nerites, Assorted Hermits & Turbo Snails

I've never seen these in my tank before. The two near the inlet appear to have hatched? Please tell me Medusa hasn't been unleashed on my tank...

 

[Andreas' Reef]

I would say its a type of snail. Medusa worm eggs are planktonic and very small