Thanks, Blue and Mrbumblebee. My ds took it really hard. We've both been crying off and on all day (the rest of the family thinks we have gone bonkers to get so upset over a fish).
It took most of the day for ds to accept that Swimmy was really gone. He kept a vigil by the tank and kept asking me if I was sure, really sure, Swimmy had passed away.

We ended up having a nice little burial. Ds was adamant that Swimmy be buried in water, so we placed him in a small zippy bag full of water and then in a nice, paper towel cushioned box with a lid. Ds made a cross of popsicle sticks and wrote Swimmy's name and today's date on it.
He picked out the spot in the yard and dug the hole himself. That was a hard thing to do. To watch.

:
Even I am a bit overwhelmed at how sad I am about this. Ds has had Swimmy for over a 3rd of his life and this is his very first experience with the death of a pet.
Today really bites.

Lisa