One of my fictional planets is a lot like Venus. Tons of volcanoes, extreme air pressure, similar density. The volcanoes are active. There is 1 creature here that depends on minerals and acids. Without acids, these creatures would be toast.
Okay here is what I am proposing for a creature who absolutely need minerals and acids:
The creatures have a cold field around them to protect them from volcanic temperatures. They are very heat resistant on the inside and as soon as lava gets into the mouth, it is supercooled. This supercooled lava is then digested by an extremely strong acid.
Then the minerals are surrounded by weak polyprotic acids. This protects them from the HCl that is in their blood.
HCl is like water for these creatures in that it is absolutely crucial to living. If HCl levels get low on the planet, a lot of these creatures will die from lack of acid.
Is it plausible that these strong acids are like water in that they are necessary for these creatures to live?