The surface of gello-pools on Deimos is immune to everything player-related.

[Uthael]

So far, I'm having a great time exploring! Here's some specific feedback about one thing that's too strange for me to comprehend...
This birdfish is swimming in the apparently amazingly thick gello-pool:

 

Here it flew through the surface, out and away.

 

Here's me trying to make waves:

 

And here's the same crack on the surface as I see it on rocks and steel.
Tese birdfish are misterious. They're not ghosts, since you can shoot them, but they seem to swim through any matter, no matter its density.

 

I like this... Liquid? ... Solid?
... This matter a lot. Despite its buggy interactions, I like how it interacts with light and the player walking on it. Could you make it dent as we shoot it and slowly revert? As deep as weapon damage allows and as wide as the weapon would damage it. There's the idea for a new toy!

Edit: A fishing quest taught me it's called Exocrine.