Pair of clownfish Fighting or Disease?

[ms asylum]

I got these clownfish in July of 2022 as a pair and put them in a 30 gallon. Originally, the frostbite was the larger one and expected to be a female. Now, the one I thought was female is slightly smaller than the expected male.
Recently, I upgraded to a 125 gallon tank and put in a female pink square anthias (who hid in the rockwork for the first 3 days). I waited until she started eating and established more of a territory before putting in the clownfish pair (which was last night), along with a tailspot blenny that was in the 30 gal as well. Almost immediately, the anthias started to chase the clownfish away from her cave but after a few hours, she was tolerating them being on her side of the tank. I’ve never seen the clownfish fighting but through research, I discovered that juveniles will fight to establish who is female and male. I have noticed, the now smaller clown, shaking next to the larger one so I assume this is normal behavior. I haven’t noticed actual fighting but this morning, I discovered that the smaller clown has a constant open mouth and possibly scars or white ish spots around the mouth. They were also very attached in the old tank but not as close in the new tank just in the few hours I’ve observed.
I did wait until the tank was cycled but I read ammonia between 0-0.25ppm this morning as well and didn’t know if this could also cause the mouth issue. I know the presence of ammonia can weaken the immune system, causing disease. Here are my other parameters in case I missed something:
pH- 8.16
Nitrite- 0
Nitrate- 0
Temp- 78.5
Salinity- 1.023
Here are also the best pictures I could take as she is constantly moving: (possible male and the injured one is the frostbite, possible female and the aggressor has 2 stripes)

Please let me know if I need to test something else or if something stands out in the pictures. Keep in mind, this happened over night. I don’t want to lose these guys, they were expensive and my first saltwater fish so I am very attached!

The last pic was from last night. Very blurry but it doesn’t look like his mouth is open.

 

[Luke Crabwalker]

What made you think the tank was cycled? a cycled tank must convert ammonia to nitrite to nitrate. Given you have 0 Nitrate I would say the tank just never got that far. Any indication of ammonia over 0 is a major red flag. I would go grab one of those reef ammonia alert badges as well from petco or any fish store. Here is what I am talking about: https://www.seachem.com/ammonia-alert.php. It will act as a separate indicator just in case the test is wrong.

As far as the fish chasing each other I wouldn't worry too much unless they are really hurting each other, its pretty normal if it goes away after a few weeks. Keep an eye on them.

 

[Darth Clam]

Just the two clowns determining the pecking order. I would add some turbo start 900 to make sure ammonia is zero

 

[ms asylum]

I had just added the 3 fish, a few snails amd hermit crabs when I made the post so I think it was just the increased bio load causing the ammonia to go up. I added bio spira at the same time and ammonia is back to 0 with nitrates around 5-10. I let it cycle for a while before adding the anthia so all is good now but I’m keeping a close eye on the levels.

It looks like his mouth is healing and they have started getting along better. It was just worrying because they have lived together since they were babies and never had issues until moving to the bigger tank. Thank you for your help!

 

[Sharkbait19]

Welcome to the forum!
Sounds like aggression to me - I would keep an eye out for any signs of bacterial infection from injuries as well as if the aggression gets much worse. For now I would monitor, but be ready to separate and treat if need be.

 

[Luke Crabwalker]

I had just added the 3 fish, a few snails amd hermit crabs when I made the post so I think it was just the increased bio load causing the ammonia to go up. I added bio spira at the same time and ammonia is back to 0 with nitrates around 5-10. I let it cycle for a while before adding the anthia so all is good now but I’m keeping a close eye on the levels.

It looks like his mouth is healing and they have started getting along better. It was just worrying because they have lived together since they were babies and never had issues until moving to the bigger tank. Thank you for your help!

Awesome! Just monitor for now and usually it works out. Beautiful clowns by the way!

 

[kevgib67]

My first two juvenile clowns did this trying to establish dominance. Scarred whiteness around the mouths which went away. Unfortunately one killed the other one. I added a new one that was over a half an inch larger and they have been together over 16 months.