A mouse would be a fossil fuel first, since the fish would be in water it would have some source of living thing.
I think the answer your looking for is smooth muscles and cardiac muscles. They only muscles that can be voluntarily controlled is skeletal muscles. Let me know if this is what you're looking for:)
Leukocytes are produced/stored in thymus, spleen, and bone marrow
The gas state. When water boils, it releases a gas we know as steam.
