Green Chromis got gash looking thing on side Good Photos

[BiGOrange]

I bought three chromis fish. The next morning this one looked like it had a big gash on it's side that was previously not there. I did not use a net, nor did the LFS. Any ideas what it was? It took about a week to do it in, I gave it garlic, no help. All the tests are fine on the tank and I added a goby 3 days ago which is fine, the other two chromis are fine too with no problems.

[Twize]

Sorry to see this happen Do you have any powerheads with open/exposed intakes?

[BiGOrange]

Originally posted by Twize
Sorry to see this happen Do you have any powerheads with open/exposed intakes?

No, all I have is the overhang box and the water is pumped back in using a standard Flexible Ball Socket Joint flat piece. It almost looks like he has a hole in his stomach.

Tankmakes are two other Chromis, a sleeper gold head goby and a small yellow tail Damsel which I gave to the pet store a couple days ago.

Tank is 125 Gallon. Skimmer is in sump.

[ATJ]

Looks like a pretty nasty bacterial infection. Did you quarantine the fish, or did they go straight into the display tank?

[Earl87gta]

Big orange are you the same big orange from the 67 72 truck board?

[BiGOrange]

nope

[Thaxx]

I've had 12 of these in my tank, not long ago. Almost all of them had this same red mark on them (though not nearly as severe as your pic) at some point. I always thought it was them picking on eachother, because it always healed up quickly, and there was normally a couple of scales missing in the same area.