What are those goos by snails?

[Lannister08]

I've syphoned out snails from my shrimp tank, put them aside for my soon to be Dwarf Pufferfish tank, well you know DP eat snails.

But i noticed some goo at the bottom of the jar. It wasn't there 2 days ago. Any idea what it is? What are the potential consequences of such goo being in an aquarium if the snails were not removed.

https://photos.app.goo.gl/Cl6G9yU3KlZDaqI93

They were from this tank. You can see the snail infestation in just one area, there are plenty more on the wall.
https://youtu.be/5O9X66FLWH8

[Emperios]

Not sure about that =(