I don't know. Is there an equivalent to humidity in water? Are there levels of dryness in a wet environment? Maybe extremely oxygenated water feels dryer the way humid air feels wetter. Does one fish say to another, "It's hot today." and the other replies, "Yeah, but it's a dry heat?" One would assume an animal that comes up for air would have a distinct sense of wet versus dry, but most fish, I have no idea. Damn it, this is going to be stuck in my brain for a week.