The rolling sounds like flashing, which is a sign of parasites or water
quality problems. The fish is not comfortable. He is trying to scrape off
the parasites or scratch an itch from something in the water. It is a good
idea to have someone scrape the fish for a microscopic examination to
determine the type of parasite, and it is a good idea to have a complete set
of tests run, pH, and ammonia in particular.
--
RichToyBox
http://www.geocities.com/richtoybox/pondintro.html

"david williams" wrote in message
...
Hi I've noticed rcently that one of my koi is performing a sort of roll,
where it swims on its side for just a moment and then rolls. Anyone any
ideas?
thanks
DW