missing scales

My "largest" goldfish (3 to 4 inches long) is missing about 4 small scales
on both sides of its body about midway between the head and tail. Its in a
29g tank with two much smaller goldfish (no other tank occupants). Its look
and behavior is normal and has been for the 8 months I've owned it. I'm
thinking it may have scratched itself on an ornament or the intake valve of
the filter. Everything in the tank was bought from a fish store so
hopefully its "fish safe". Is this a normal thing that happens, an injury,
or possible infection?

Water parameters:
ammonia 0
nitrites 0
nitrates 5ppm
ph 7.2

Thanks
E.Otter

In article link.net,
says...
My "largest" goldfish (3 to 4 inches long) is missing about 4 small scales
on both sides of its body about midway between the head and tail. Its in a
29g tank with two much smaller goldfish (no other tank occupants). Its look
and behavior is normal and has been for the 8 months I've owned it. I'm
thinking it may have scratched itself on an ornament or the intake valve of
the filter. Everything in the tank was bought from a fish store so
hopefully its "fish safe". Is this a normal thing that happens, an injury,
or possible infection?

Water parameters:
ammonia 0
nitrites 0
nitrates 5ppm
ph 7.2


Yep, it can happen fairly easily, actually. (S)he probably chased
some food into a narrow space between objects, then struggled to
get out. Barring other problems, it'll eventually grow back,
but you should try to eliminate such tight spots if possible.
(It can also be caused by disease or parasites, but mechanical
trauma is most likely.)

BTW, the scales that grow back may be a different color, or
misshapen -- one of mine now has two white spots on each
side where he rubbed off 2 or 3 scales.

Gunther

Thanks.