what to do when catheter tube has bubbles in it

I have a 1994 Honda accord and I checked my transmission fluid & it had bubbles on my dip Stick. What does dat mean??

central vacuole

The leavening agent reacts with moisture, heat, acidity, or other triggers to produce gas that becomes trapped as bubbles within the dough. When the dough is baked, it "sets" and the holes left by the gas bubbles remain, giving bread the baked goods their soft, sponge-like textures.

You are supposed to have bubbles in your fish tank or else your fish will die because they don't have enough oxygen.