I bought a large seedless watermelon 2 days ago, and I made sure to check for the following:   Yellow underbelly Hollow sound Solid rind   When I got home I left on the kitchen table. The room temperature was around 25-27 degrees C. Today, I touched the rind and it felt soft! I cut it open and I saw that the white pith had rotted.   Can anyone explain what the possible cause of this is?   (I've left watermelon out on the dining table for days at room temperature before, and nothing like this has ever happened. I should also mention that:   The watermelon was whole and unblemished.  There were no fruits around it and it wasn't in a bag, so the ethylene explanation is out.  
I find the wild salmon to be less fatty and easier to overcook.  I take off a few degrees from final temperature to keep the texture flaky, somewhere between 125-135. 