So Jo Ann,

Test for ammonia and/or nitrites. Rule that out. If they readings are up
you may have your cause. If you are worried about Parasitism's do a gill
scrape and look under a microscope for bad bugs. If the area is healing it
will blacken, but you need to figure out what caused it.

Tom L.L.
===========================
"FBCS" wrote in message
news
Yes Rich, but the second paragraph states-
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Another type of blackening is a generalized type wherein the fins and
body may develop a blackening change from chronic or caustic trauma. Case
in
Point: Fish are badly ammonia burned by a filtration failure or
inadequacy --- A week later, after water quality is restored, the fish
develop blackened areas, called a Melanophore Migration. Severe
parasitisms
can later cause blackening as the skin starts to heal. The blackening is
not
permanent, but may remain for two to four weeks before subsiding.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

So maybe they are healing from something.

Joann

"RichToyBox" wrote in message
news:68u7b.406624$Ho3.62101@sccrnsc03...
Joann,

Shimi's are black markings on kohaku koi, usually, that are not supposed
to
be there. It is apparently caused, per some, by the sanke coming out in
them. Makes for a good kohaku into a very poor excuse for a sanke.
There
are methods of surgically removing shimi's.
--
RichToyBox
http://www.geocities.com/richtoybox/pondintro.html


"FBCS" wrote in message
...
I just came across this at Koivet, is it a possibility?
Second paragraph - they have not seemed to be sick. Joann
snip
Black Spots Appearing
Some little black spots are called Shimi. This is an unfortunate
genetic defect in some fish wherein a Kohaku gets some little black
dots
and
they're suddenly a worthless Sanke. There is also a growing body of
evidence
that suggests the condition may be common in water with high turnover
or
exposure to caustic irritants like Chlorine. Case in point: Shimi is
rarely
noted in natural greenwater ponds but is common in crowded manipulated
reuse
systems.
Another type of blackening is a generalized type wherein the
fins
and
body may develop a blackening change from chronic or caustic trauma.
Case
in
Point: Fish are badly ammonia burned by a filtration failure or
inadequacy --- A week later, after water quality is restored, the
fish
develop blackened areas, called a Melanophore Migration. Severe
parasitisms
can later cause blackening as the skin starts to heal. The blackening
is
not
permanent, but may remain for two to four weeks before subsiding.


"FBCS" wrote in message
...
Ingrid help, anybody else can jump right on in with suggestions.

I noticed some of my GF have black in their gills (inside). Is it
something
to be concerned about. I have tested the water and all seems fine.
They
look
fine none are wacking out. None of my Koi have this. I never noticed
this
on
them before last week. What made me notice was one of my ugly black
GF
that
I thought was gone showed up a pretty red gold then I noticed the
black
inside the gills thought it was his coloring then I noticed some of
the
others had the same thing. I have read about gill damage, is this
it?
Joann