Cory's Missing Tails

I've been trying to stock my 75 gallon with cory cats (sterbaI and albino's) - but I've noticed a lot of them have died, and one thing in common is their tails end up missing.

I don't notice too much aggression during the day - other then the once in a while "get out of my spot" nipping. Also, I've had two Albino's that have survived since day one, one I got that was just out of fry stage and they both are thriving. I just added 6 SterbaI cory's, and 2 of them have already died, both with tails missing. I thought maybe they died then got eaten, but one was still barely alive when I notice its tail was gone.

Could they be getting caught in something? Or are they just victims of a semI aggressive tank? I have 2 GBRs, Dwarf Gourami, 2 Angels and one Satanoperca juruparI (he was added late in the game, most of the deaths took place before he was added). Also a Chocolate Zebra Pleco that is mostly hidden in terracotta pots or under driftwood.

I was thinking of possibly moving them to my 36 - but the last set of cory's I had in that tank were very skittish when I moved them there. Also, it's about 5 degrees cooler then the 75 gallon.

 

Can you show pictures? There is a visual difference between bites and rot.

 

Augh! That's horrible! I wish I could be of more help, hope your cories get better. They are the best in my opinion, of course that's up for debate but I just love them and their little personalities. Some people say they are a very hearty fish, but I tend to disagree all kinds of stuff has happened with mine as well. I feel they are very sensitive to the medications and water parameters, I've had them pass with .25 ammonia! There's a local fish store that's absolutely awful when they receive new fish they put non compatible species together(archer fish with mollies, puffer fish with well any other fish etc) and I've noticed that cories have been without tails, oto without eyes etc. In my opinion, it sounds as if the stress of being picked on as well as the loss of tail could be what the problem is. Or if there's any ammonia spike that maybe you're not aware of?

 

Pictures?

 

Water parameters? pH, temp, ammonia, nitrites, nitrates

Are their barbels missing too?

 

My guess is a progressive form of finrot.
Had that ones in a Venezuelan.
Never grew back !

 

Water parameters? pH, temp, ammonia, nitrites, nitrates

Are their barbels missing too?

First of all - I unfortunately didn't take pictures - I didn't even think of it, I just got them out of the tank, examined them a bit and disposed of them.

Parameters are as follows: Ammonia 0, Nitrite 0, Nitrates 10 Ph 7.2, temp is 80F (fluctuates slowly between 79.5 and 80.5)

It's RODI water, I use Seachem Equilibrium, Acid and Alkaline buffers. Planted tank, Seachem Flourish is used regularly, Flourish Iron and Potassium sparingly.

Barbells in tact, one one of them it was part of the caudal fin, on another it was completely gone.

Just as a side note - I had emerald green cory's in this tank for 6 months with no issue - but they were housed with a different stock of fish - but same parameters (other then temp), filtering (2 x Fluval 306), substrate (eco complete), and similar decoration (plants, driftwood, terracotta pots).

 

I agree with DD, as it sounds like you're doing everything right. Might be worth QTing them and treating them.

 

I agree with DD, as it sounds like you're doing everything right. Might be worth QTing them and treating them.

I'll setup the QT tank. They will be cramped in a 10 gallon. Should I put substrate in? What is good for finrot? I heard Cory's can be sensitive to meds.

 

Is there a good current / flow in your tank ?

 

A thin layer of sand is preferable to a bare bottom in a QT for cories. An antibiotic would be my choice, Kanaplex or erythromycin might be good first options.