No other signs of a parasite attack? It could make them flash.
Just a thought,
Per Johannesson

"Jerrispond" skrev i meddelandet
...
3 days ago I noticed a sore on my large koi, today there is one on another
koi.
Both koi are white females, one a butterfly. Both are about 20" and in
great
health. They are on the side of one and the top of another. the one with
the
sore on its back has a large shred of skin following. It looks exactly
like
they rubbed on some of the rocks. There is no preditor behavior and both
are
being social and eating like the pigs they are. My question is....why
would
they get scraped on the pond for the first time within 3 days of each
other,
and in a pond they have been in over 5 years? Do female koi go after each
other for territories or males ....or any strange thing like that???
Would the
channel catfish ( who is their size) gone after and scared them for some
reason
??? Any ideas They have spawned in this pond for several years and
never
got scraped up. Jerri


http://www.fringeweb.com/Ponds/JerrisPond