disappearing goldfish

Question
I have had fish in bowls and aquariums for approx.thirty years.  The present tank is a 5 and half gallon with charcoal filter, I either have 5 or 6 fish.  I say ths because last year a fish disappeared and never found (dead or alive)  Last month another one of my fish mysteriosly vanished for 8 days and then reappeared (unfortunately dead),which proves the others did not eat him. Last week my other fsh disappeared and could not be found. I removed the filter, castle and large shells to see if it was stuck.This morning it was there as plain as cou.ld be.  My sister feels it was burrowing in the gravel the entire time. I find this hard to accept because I did not see it eat with the others and it must move around to filtrate the gills. If you cannot hepl me I think that I will nickname the tank "The Haunted Aquarium" It is frustrating because the tank is set up in the kitchen where everyone views it several times a day;the fish are not neglected. Also note that the ones that have gone missing or vanished and died are brightly colored, so they can't be missed or camouflaged. Thank you for asssting me. Whether you think you can solve the mystery or not, a reply or theory would be appreciated.

Answer
Hi Patricia;

Hmmm?! A mystery indeed!

Goldfish don't burrow. It would tear up their skin and they wouldn't be able to pump their gills from the pressure of the gravel. Is someone playing a practical joke on you? Other than that, I don't have a clue!

You might try posting your question on this forum at About.com;

http://forums.about.com/ab-freshaquaria/start

I post there too. Lots of great folks that may be able to help us out!

Followups welcome

At Your Service;
Chris Robbins