Join Date: Aug 2012
Location: Minneapolis, Minnesota
He's certainly not dying XD The oak leaf helps encourage instinctual spawning because it floats similarly to Indian almond leaves, which fall into the natural habitat of bettas and are commonly used to shelter bubble nests. Just be aware that leaves have a habit of capsizing after a certain amount of time and ruining bubble nests, so if you ever did spawn him you might want to consider taping the leaf securely to the side of the tank or offering him styrofoam/bubble wrap/plastic lids/other things that will definitely float long term.
The temperature increase could have also sparked his spawning behavior, and since he skipped his breakfast he's clearly serious about this nest. One way breeders get bettas in the mood to do this is turning up the tank temperature on purpose. Don't be surprised if he continues to refuse food for a couple of days, he may be waiting for his "spawn" to hatch. Sometimes male fish forget that they can't have babies on their own XD Many will not eat until their fry are safely free-swimming, which takes 3-4 days.