Bill Stock wrote:
I have a Rosy Barb with a chunk out it's tail just ahead of the fins. The
wound looks fairly round like an Ulcer or something that popped. But it
could also be an attack from another fish(es). The fish is still active and
eating, but I'm still tempted to pull him out. I've lost a few Barbs (4)
over the past few months, one at a time. All looked like they'd been pecked
at. Before or after death I can't say. I'm also missing a Tetra, but they
have been in there for months. I'm wondering if one of my SAEs is a CAE in
Sheep's clothing.

Have you had time to sit watch your fish interact?
Sometimes I have caught the aggressors by sitting down by the aquarium
for a while and warching the interaction.

You also may have aeromonas from the description you gave. Aeromonas is
often in an aquarium and is an opportunistic bacterial pathogen.
You might try a methylene blue dip on the wounded fish.
Then treat your fish in a hospital tank (if available) with Kanamycin
or nitrofuracyn. I prefer Kanacyn in higher pH and furacyn in lower pH.
Melafix can work for aeromonas too

Here is more info about aeromonas:
http://www.americanaquariumproducts....Aeromonas.html

Carl