[lurrch]

I have a green cory catfish that has had its fins torn up and I don't know who or what did it. I have several other cory catfish that haven't suffered any damage. I've moved it to another tank, but I would really like to know if this will happen to my other fish.

Stock (75g tank):
3 (now 2) green cory catfish
3 peppered cory catfish
9 zebra danios
9 boesmani rainbowfish
3 otos
1 bristlenose pleco
snails


The tank has a number of large shade producing plants as well as a couple of ceramic huts. My other cories seem to enjoy sitting under those, but this one liked to swim in the middle of the tank (though I only noticed this after he had some damage). I never saw anything show any aggression towards it, but who knows what happens when the lights go off.

 

[sampster5000]

Keep a close eye on the danios and rainbowfish. A quick fin nip happens in the blink of an eye. Some dont do it aggressively. They just do it quickly then go back to normal. Thats all I can think of.

 

[JSA]

If it were just damage to the fins, I think you could assume aggression, but your header indicates the barbels also show damage. To me this suggests illness or abrasion.

Julia

 

[wkndracer]

either way on figuring out what did it (bacteria or aggression) lots of clean water is the best help you can offer the damaged fish. do partial water changes daily on the recovery tank if you can.

 

[lurrch]

I'll do the water changes. It's a 10g and I have a Python so it takes 10 minutes.

I tested my water and everything came up normal (a little on the soft side). I first noticed this about 2 weeks ago, and none of my other cories seem to have any problems. I would think if it were environmental or disease, they would have shown some signs.

I think it may have been the rainbowfish. I have a bad male/female ratio with 5 males, 4 females (up from 3 around the time this happened), and one that I thought was a female but is looking oranger. I've keep trying to get females, but I'm not able to tell the difference very well in the store.

 

[pinkertd]

You could be getting fins nipped, but with the damaged barbels it's definitely from substrate that is not clean enough. Not all cories suffer barbel damage from dirty substrate at the same rate of speed. You need to do better gravel vacs with each water change. Barbels will grow back but it takes quite a while. Sometimes in addition to seeing the wearing away of the barbels, you'll also see wearing away of the pec fins as well.....dirty substrate. Vac, vac, vac.

 

[Razorworm]

What is the tank's substrate?

 

[wkndracer]

What is the tank's substrate?

While many, many threads dealing with barbel erosion blame sharp substrate this is slowly being proven to be more a cleaning issue rather than a substrate problem most of the time.

I've kept Cory over Flourite original for years and many claim it to be the kiss of death. Currently have them over Black Beauty blasting grit with the same results. Sadly for those saying this will destroy barbels and ultimately kill the fish mine are happy and healthy.

What pinkertd posted above is the best medicine for treating barbel issues 99% of the time.

 

[lurrch]

I have eco complete that I vacuum at least once a week. As far as I can tell, the only people who think that eco complete hurts cory barbels are those who don't have it.

I don't see how a poor substrate or water conditions could cause the damage I see on the caudal and dorsal fins.

 

[JRMott]

Fins and barbels sound unrelated.

Even though you're gravel vacuuming weekly, perhaps you're overfeeding? Based on your fish, I can't guess who the aggressor would be. I've had most of these fish and never had problems. If it was anyone, I'd think the Danios, but mine always kept to themselves and rarely left the top of the tank.

I too am leaning towards illness over aggression.

No one has mentioned it, but if I remember correctly, cory cats are very sensitive to aquarium salt, so whatever you do please google that before putting any in the tank to 'help' their recovery.