Sick Cories?

[Vodalian]

I recently moved my Emerald Green Corydoras to their new home with everyone else... They were previously stuck in my 10 gallon quaranteen tank until my new 35 gallon tank was done cycling. Well about 4 days ago it was completely cycled out so I moved everyone.

All my fish are doing great... they are all very colorfull and happy, except my cories . Before my cories were happy little fish swimming up and down the glass all day long. They would always shoot to the surface for a gulp of air, and were always winking at me! Now when I sit and watch them they rarely move... they have taken on this very dark nearly tarnished bronze color, and rarely head to the surface for gulps of air. I have inspected them and they dont have any signs of illness, its just they have become lethargic and changed to this very dark color. Also whenever I had my hand in the tank moving stuff around they would tear off to hide in a cave or behind some plants. Now when I have my hand in the tank they rarely move, and I can nearly pick them up with my hands.

Anyone have any ideas? I really miss my active happy little cories! I might just scoop them out and move back to my quaranteen tank... was thinking about using it for a cory breeding tank anyway.

 

[Corys4u]

If they are gulping air from the surface it may be an idea to add an airstone to the tank. The reason they are coming to the surface for air is because there is not enough Oxygen in the water.

What are the stats in the tank and other tank mates?

 

[Vodalian]

Tank mates are in my signature. I have a 10" bubble bar that makes a very nice wall of bubbles along the back. They do get air from the bubbles, but like all cories make their way to the top for a gulp of air as well.

Tank is fully cycled... P.H. is sitting at 6.8 temp is 78F, ammonia is 0, nitrites 0, nitrates 40. I read that aquarium salt burns them... I did add aquarium salt to the tank, but it was well before adding them. Do you think that there might still be the presence of aquarium salt in the tank?

 

[WILDER]

Darkening in colour can indicate a bacterial infection.
Corys are very prone to bacterial infections, what do there barbels look like have they changed.

 

[Vodalian]

Yes their barbels are darker in color as well... i'll pull them out and add them to my hospital tank. What is a good way to cure a bacterial infection?

 

[WILDER]

I think I would go in with some maracyn plus.

 

[Vodalian]

Ok upon closer inspection their barbels are a white color at distance but when close they are somewhat clear. When they are swimming around their barbels match their bellies. Also the dark color seems to be getting lighter at the tops of their backs... i'll keep a close eye on them and if there isnt any more improvement i'll start adding meds.

 

[WILDER]

Good Luck.

 

[jollysue]

Emerald Catfish/Cories or more properly Brochis splendens are not really Cories, they are Brochis. The emeralds do darken. Mine were very dark when they were in a tank with a black substrate. I have moved them to a deeper tank with a salt and pepper colored sand substrate, and they have lightened up. I can see their green again. They can get a little shy with other tank mates. Who are they with? Cories and Brochis really do like "Cory" only tanks. My first guess is that they were happy in their old tank and are unsure of the new one.

I had a Betta with the Emeralds once, who took to chasing them around and harrassing them when I wasn't looking. I noticed their changed behavior and eventually caught the culprit. It took them a long time to to get happy again.

 

[Vodalian]

They are in with the fish listed in my signature. The tank does have black gravel in it so that could be part of the reason. No one picks on them... they usually are sitting around left alone. I was just worried because they arent as active as they used to be. They always used to swim up and down the glass all day long or in the bubble bar.

I'm getting ready to plant my tank... perhaps a change of scenery along with more places to hide will help their stress?

 

[jollysue]

As I mentioned, I just moved mine. I moved them from a 20 long with the currents subdued for the long fins' sake, and the temeratures a little lower also for the longfin peppers' sake. They moved into a 40 Tall with a strong current and higher temp. I don't know if any of these things affected them or not. They swam around a bit in the 20 long, but in the 40 tall they are swimming all over. The whole tank is extra active now. The sterbais were out and around before, but they are much more active now. I don't know if it is temporary or the dynamics of the new tank.