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All of the information came from WetWebMedia.com
Disease FAQs on Loricariids, South and Central American Suckermouth Cats 2
"Yesterday I noticed his sucker was pinky/red sort of uneven. Is this
normal? I am assuming not. Could it be heater burn? Could it be
bacteria? Could it be a sign of gill flukes? What do you all think?
"It "could" be any of the above. My bet would be bacterial, but it
could be from something as simple as eating algae off of a rough rock.
Keep the water clean, remove all but smooth rocks and watch her. I
would not treat unless you see it get worse. Then a good broad
"... and noticed that he has developed a white spot on his side/back
that is surrounded in a milky colored haze (mucus?)"
"This could be a Protozoan infestation called Chilodonella. Treat the
fish with Metronidazole for about 10 days. Should clear it right up.
Move him to a QT if possible. Test the water whenever treating and
correct any spikes in ammonia or nitrite with water changes. Replace
med in new water."
[ QT = Quarantine Tank ]
Plecostomus with strange red splotches
"Plecostomus a few weeks ago and today I noticed that its fins looked
tattered and it had strange red, almost bloody looking splotches.
<Mmm, if you've had the fish this long, there is something in your
present system that is mal-affecting it>
This morning it wasn't too bad, but it has gotten noticeably worse as
the day went on. He or she is still breathing and moving a little
although it's not eating. In the morning it was on its back
<A very bad sign>
...and I flipped it over with a net. I only have a total of 4 fish in
my 10 gallon aquarium (3 platies and the Plecostomus its about 2 1/2
inches) and please write if you have any ideas about what I can do
because I am very concerned. It also had a few indentations that
looked similar to pock-marks. Will it contaminate my other fish?
<Have you water quality test kits? What are they telling you? Do you
have measurable ammonia, nitrite? What is the water pH? I would
quickly do a good 25% water change (vacuuming the gravel if you have
such a tool) and add an ammonia-nullifying product (e.g. Amquel,
Re: starving pleco
"Today I noticed that he has a small red circle on his belly that
doesn't look like a cut, lesion or abrasion, but something under his
skin (was not there yesterday). Our gravel has some angled shell
pieces but mostly rounded medium sized rock, so unless he is so
delicate that he bruised himself on the rocks or wood ...Any ideas?"
"it?s possible that he just rubbed himself on something."