Clown Fish Gill Issue

[NewFishGuy]

I bought a pair of clown fish tonight, from an out of town shop while on my way back to Brantford. All the clowns looked fine when I was viewing them in store, but once I got home and had a closer look, one of the two has a strange issue going on with its Gill. Being fairly new to salt water, I'm not familiar with the diseases/maladies just yet. Is this a disease or a wound from aggression?
The other clown appears to be fine, swimming around the qt, very energetic. This guy is only slightly less so. Not acting sick/injured per se, just slightly less active.

 

[LIttle Reef Keeper]

It's looks to be deformed. The head is sunken in and seems to have either flared or a short operculum.

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[SamB]

If the fish is breathing and swimming normally, you can watch and monitor the situation
If recently purchased, perhaps ask the seller for a replacement but if it's just a birth defect, that might be kinda cool !
I've attached a good resource for clownfish diseases

http://www.wetwebmedia.com/clnfshdisart.htm

 

[NewFishGuy]

Thanks guys. I emailed the seller last night when I noticed the issue, so will see what they have to say about it.