Fish that can stay in place like hummingbirds

I saw that ther are some fish In real life that can move their fins opposite direction so they can stay still or move backwards. Would be cool to see it in game. They could go into dark places or stay still in vegetation, also including caves.
There's already seaweed and for the movement of water the most realistic thing would be having ultrasound detection for the predators but that's another suggestion so I think it'd be best to do this in 2021 when the game has already been released.

Tom Johnson

Developer of Ecosystem
There is some support for creatures being harder to see in dark places or if they match the foliage, though at the moment their behaviors are quite simple so they are not smart enough to know when to do something like this. Enabling more complex behaviors is definitely on my list but it is likely that it will be something I add after the initial Early Access release. I will keep this idea in mind when I get to that point though, thanks.