Unhappy cory?

[CrashCourse]

I had 6 cories in my 20 gallon community tank, and one of them had gotten injured. I think he was getting picked on, which is weird because he was one of the bigger guys in the group. I never noticed any aggression, but he lost pretty much all but his tail fin, and it looked like nipping, not fin rot or other disease. There were also no other injuries in the tank.
He's in his own in my 10 gallon right now with 4 xray tetra, and he's healed up nicely. Some of the fins, I doubt will ever grow back (he lost spines and all), but he seems healthy. I'm considering putting him back in the 20 gallon so he's not alone, but I'm not sure if its a good idea. I know I'll just have to try, and watch carefully for any other signs of injury. I'm just not sure if its worth the stress it'll cause him.
He hides a lot, and is not very active. Ill see him playing in the bubble wall from time to time, but other than that, he doesn't come out much. He hides in a back corner most of the time, and I've had to start feeding him in his corner, because I never saw him come out for food. But at least he's not being picked on.
My real question is this: how do I know if he's unhappy being alone, or if he's better off where he is? What are the signs of stress for him to be alone, considering they are a schooling fish?

 

[Lardeelion]

If he's hiding a lot, that's a sign of a sad cory. They are normally so gregarious and playful. Shoaling fish really need to be with their buddies. If it were me I'd give him back to his family and keep an eye on him.

 

[CrashCourse]

that was kind of my thought too. I wanted to at least wait until he was fully healed before I put him back, it was that bad. he had fungus growing out of the injuries and everything. I really don't want either of us to have to go though that again.

also, love your location.
thanks!

 

[Lardeelion]

that was kind of my thought too. I wanted to at least wait until he was fully healed before I put him back, it was that bad. he had fungus growing out of the injuries and everything. I really don't want either of us to have to go though that again.

also, love your location.
thanks!

I think you took the prudent course of action. Always better to isolate an individual with a possible contagion.

And thanks. It's quite a place. (That's only half-sarcasm.)

 

[CrashCourse]

And thanks. It's quite a place. (That's only half-sarcasm.)

Oh I know... Haha.

 

[CrashCourse]

So, I moved this guy back to the 20 gallon on Christmas Day. Good news, he's happily back in the group and much more active.
Bad news is he seems to have lost another chunk of his dorsal fin, that was finally growing back, and the fungus is returning on a different nub. The water quality is better in this tank (0 across the board) than in the 10 gallon, which is going through a mini cycle right now. Both get vacuumed regularly.
He eats, but not as well as the rest. He's got a bloodworm sticking through his gill right now that he can't seem to shake.
I don't want to treat the tank for fungus, as it doesn't seem contagious. From what I've read, it could just be growing out of necrotic tissue surrounding the injured fin, although I thought it was healed.
Now that he's come out of hiding, I'm able to observe him much better. And in comparison to the rest of the group, he doesn't seem to have grown at all. The ones that were originally the same size, are now double that. Even the runt of the group is the same size he is now. I keep hoping that he'll heal and start to grow again, but that doesn't seem to be happening yet (healing-wise, I don't expect him to grow noticeably so fast). He's just all around very skittish. Especially at feeding time, he'll hang out in the back and only go up for food once everyone's occupied, even though he doesn't seem to be getting harassed.
I just don't know what to do for him.

 

[Tetra1990]

You might move him back to the 10 and let him heal. Then think about getting 1 more Cory and add it to the 10 so he's not lonely.

 

[CrashCourse]

I thought about it. Thing is, since the 10 gallon is having its mini cycle, I don't want to move an injured fish into worse water conditions.
I had bought him a friend when he was by himself in the 10, but he didn't do well there. The new one ended up in the 20.
I don't want to buy any more, because eventually I'd like to keep them in the 20. I'm already pushing it with the stock in that tank, and I don't think the 10 would be able to support a couple of extra cories.

 

[CrashCourse]

Can fish bruise?


This poor fish. He's about to get his very own 2 gallon.

 

[CrashCourse]

Could this be septicemia?

It looks similar to the pictures I've seen. One source says its bacterial, and enters the fish through an injury (his damaged fins) and is not contagious, but is most likely deadly. Someone else says its viral and highly infectious. Everyone else looks ok though.
Anyone have any experience with this?

 

[beginner on the loose]

Nope, no experience with septicemia but I like you have a 10 and a 20 I shift between and own a fair ammount of corys. The thing is if the water is better in the 20 you might want to keep him in there, corys are shoaling fish and need their bros. It might just take time, though I would advise you to keep a VERY close eye on him and if the slightest thing gets worse throw him into the 10 as to not compromise the life of the other fish.

 

[CrashCourse]

He didn't make it, poor guy. My unofficial diagnosis is bacterial septecemia. He followed all the symptoms. The bruising was internal bleeding, and he just got more lethargic until he died.
I took him out if the tank yesterday, in case he passed while I was at work. I didn't want the other fish nibbling on him and spreading the bacteria. He hung around through the day, but I lost him overnight.

 

[Tetra1990]

He didn't make it, poor guy. My unofficial diagnosis is bacterial septecemia. He followed all the symptoms. The bruising was internal bleeding, and he just got more lethargic until he died.
I took him out if the tank yesterday, in case he passed while I was at work. I didn't want the other fish nibbling on him and spreading the bacteria. He hung around through the day, but I lost him overnight.

Sorry to hear this.

 

[CrashCourse]

Thanks, me too.