# Serpae tetra mystery black spot and fin tear



## Zwicker (Jan 6, 2011)

Hi all! About 3-4 days ago I noticed that one of my serpae tetras had developed a blackish spot towards the back of it's anal fin


The spot was accompanied with a little discoloration that expanded out to the edge of the fin, but nothing else. By the next morning the fin had developed a tear along with the spot (this pic was taken today...things don't seem to have worsened since the tear was first noticed)


Needless to say I'm stumped. I haven't noticed abnormal behavior from any of the fish as far as aggressiveness or fin-nipping goes, so I can't confidently attribute this to an injury, altho I'm not home for most of the day.
My tank did finish cycling recently so I haven't been changing the water every 1-2 days like I used to...maybe water quality is the problem? I have been checking chemical levels tho and for the most part things are holding steady at 0/0/10-20. Behavior seems normal as well. Regardless, I'm going to do a large water change tonite and every 1-2 days for at least the next week to see if things get better.

Can anyone help diagnose what this fish might be afflicted with and/or provide suggestions for treating it? Thanks a lot!


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## Gizmo (Dec 6, 2010)

Could be parasites. I've noticed discoloration and "spikes" of random whatever-it-is around my zebra danios` anuses right before they die, and I can only attribute it to possible parasites. Feed your fish mashed garlic, or their regular flake food soaked in garlic - this will kill internal parasites. Watch for long white stringy poop from that fish or any others, as this will indicate not only that other fish have parasites, but that they are pooping the eggs out. If you see this, buy some anti-parasitic water meds and start dosing.


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