cory injury. help please

[laur94x]

In my 138 litre long I have 5 male guppies, 5 white fin rosy tetra, 3 albino cories and 1 bn pleco. The other day I randomly noticed a big red mark on one of my albino cories side and I can't work out what Is causing it. At first I thought it could be some sort of parasite or something but now I'm wondering if he could have been attacked.

The only agression issues I ever had was the guppies fighting amongst themselves because they're all males but nothing bad. then I added the tetra a few weeks ago and all the tetras do is chase eachother round and a couple just hide. These aren't meant to be nippy tetra but I also found a split fin on one of the cories the other day which I've never had in the past and I'm wondering if they're attacking the cories.
My bn pleco keeps herself to herself and the guppies only seem to have a problem with eachother, they've lived happily with the cories for quite a while now.
So, from the rubbish quality picture, do you think he's been attacked by a tetra or does it look like something else? Its only on one side, looks like a graze or something but I can't think what else he could have hurt himself on. How likely are the tetras to attack him? He is the smallest cory and swims the least so an easy target. Thanks

 

[laur94x]

Sorry the pictures are rubbish, taken from my blackberry. Its a lot more red than it looks in the pictures. There's definitely blood just can't tell if its internal

 

[Dallascowboys16]

Keep your water clean

Looks like an injury of some kind for sure so the best thing you can do for right now is keep you water SUPER clean to keep it from getting a secondary infection. He should get better but there's no telling. Good luck

 

[laur94x]

Thanks for your reply, ill do extra water changes for a while and see how he gets on. Its not looking good though he's just laying at the bottom loads where as the other 2 are swimming around like normal

 

[laur94x]

Well all 3 of my cories are huddled in a corner, not like them at all, they're normally shooting around the tank, and the 5 white fin rosy tetra are all grouped up about 4 inches away from them just watching them. I think they're waiting for the cories to come out from behind the plant. So my guess is the tetras are attacking the cories, in which case the tetra are going back to the shop tomorrow, I'm sick of them attacking eachother and possibly my cories x

 

[Kimlafeiet]

I hope your cory heals ok. I would bet it was the tetras. I tried several schools of tetra, and all of them were too aggresive for my liking. The only ones I have had any luck with are neons......in a school of a dozen. Luckily, they do great in my community tank.

 

[Coursair]

Make sure there are several hiding places. BN Plecos will defend "their" caves sometimes.

 

[laur94x]

Thanks for the replies. Well the tetras went back to the shop last night, I kept catching thhem surrounding the cories and going for the guppies and cories if they dared to go near the bottom of the tank. I've never returned fish but I'm not risking my others getting beaten up by them and after the way I've seen them acting I'm pretty sure it was them

 

[Teakwood]

How weird! Cory's are like the universal 'most fish get along with' fish.