Green Cory tail injury advice please

[ShinyMoose]

Hello, about 3 weeks ago I added 5 Cory’s to my community tank since I had only one in there prior, and the other day I noticed one that seemed to be swimming weird and was dark around the middle so I assumed it was stressed. I looked closer at it and most of the tail was missing!

I’m not sure if it was picked on and nipped by another fish, or somehow got injured, or if it’s possibly fin rot, although this looks like a clean and not jagged looking tail end so I’m assuming not fin rot. The other tank mates are neon tetras, two Bolivian Rams (one Ram was purchased the same day as the Cory’s), and a small freshwater crab. I have seen the newer Ram occasionally chase after the Cory’s, and another Cory seemed to be chasing the injured one a little before I got it out of the tank. The crab leaves everything else alone so I don’t think it was the crab.

This is a 45 gallon tank and the water parameters are 0 ammonia, 0 nitrite, and about 20 nitrate.

I was able to remove the injured Cory and put it in a hospital tank which I’ve been treating for about 4 days now with Melafix, I don’t see any changes but I read it can take a while for fins to grow back. I’m wondering if I should be doing something else for him, and should I keep him in the hospital tank until the fins are completely healed? I wasn’t sure if him being alone in a tank for that long would be ok.

He seems to not have grown at all either since I got him, he’s much smaller now than all the others I got at the same time which were all the same size. He does eat though. I’m not sure if this is because maybe he had this injury a while before I noticed it? I have a lot of plants and hiding places in my tank and the other Cory’s are quite active.

I’m attaching a photo of the injured fish (I think it also might have damaged side and under fins), and also a photo of one of the other Cory’s I got at the same time for comparison of the tails. I’m hoping his tail isn’t too injured to regrow since it’s down to the stub. His barbels also look a little small, but hard to tell.

 

[Motherlovebetta]

What is the black substrate? If it’s black diamond blasting sand I had that and my cories underbellies were all beat up and the barbels were damaged as well. I know I see mixed reviews about whether or not it causes it, but I swapped it out for sand and then barbels grew back and bellies healed. The tail……may be the crab. As long as the cory is swimming fine and the tail doesn’t have open areas I personally would put it back with the other cories. The tail will take awhile to grow back. I have a clown pleco I saved (from a crab) at the LFS that has been sllllowwwlly regrowing a tail in my nano tank for a couple weeks.

 

[ShinyMoose]

The black substrate is just plain black sand from Petco. That’s what I have in the hospital tank which he/she’s only been in for 4 days. I was worried the Cory would continue to get picked on. I was leaning towards the culprit being the new Ram as I can now tell it’s another Male, and it’s been aggressive since I’ve gotten it. I was hoping to have picked a female for my sweet original Ram. I guess it could be the crab, but I’ve only seen it shy away from any fish or snails that come near it, whereas I’ve seen the new Ram chase the Cory’s and also the bigger Ram I have. I’ve been considering taking the new Ram back and getting a different one but they are so hard to catch! Lol

So, the tail fin will take a long time to heal, what about his side fins? It does struggle to swim, but can swim some. So should I leave it in the hospital tank until it can at least swim well enough to get away from whatever is picking on it?

 

[Motherlovebetta]

Could be the ram then. Yea, if it’s not swimming we’ll would leave it separate until you can rehome the ram. I’ve never kept rams i dont know if the other male will become aggressive towards the cories if he’s breeding. The side fins should come back too. I had a cory swim into a wave maker a few months ago got pretty beat up and I can’t even tell which one it is now.

 

[ShinyMoose]

My older male Ram is super sweet. I had gotten a female Ram before to pair it with who was also super sweet and they were always together, but unfortunately I could not get her to eat anything from day 1 (and I literally tried everything), she eventually perished after a month of not eating. So I tried to get another female, hoping for another sweet one like the last but instead got an aggressive male. He’s still a lot smaller than my original Ram but sometimes still goes after the bigger one, but the bigger one shows him who’s boss. The bigger one has never been aggressive to anything else in the tank so hopefully he stays that way.