Clown acting weird....dying?!

[drew61199]

This is a newer tank (15g - setup 3mos). I have two clowns, a watchman goby, and a Randall's shrimp. One clown has always seemed to be a "weaker swimmer"....fins are always moving super fast....more spastic in general. This morning I noticed it was swimming at the top of the water vertically (Mouth up), but when I fed, it chased after some food, ate, etc, so I didn't think much of it. I just came home and found it in my rockwork....laying down in a crevice....and the other clown will go "nuzzle it" (not sure how long it takes them to bond, but they're definitely fond of one another)....and then the 1st clown would shoot out, swim around all frantic again, and lay down somewhere else. It seems totally unnatural. Visually, it looks fine as far as I can tell.

My last water change was 5 days ago. Two days ago I added a hammer, frag of zoas, and a small favia. All other occupants, corals, etc look healthy. I just checked basic parameters - salinity is 1.026 and Nitrate 10ppm.

*EDIT* for pic / video
So you can see the fish on its side on top of my rockwork - this is where it rested after it came out of the original crevice. I then turned the lights to full white so I could take clearer pic/video and it hasn't stopped swimming now. I dropped a few pellets in and it attacked them instantly. You can see how much "harder" it appears to swim, but has always been this way.

Maybe all is okay, but my last clown lived to 15 and only died bc my house flooded and breaker tripped and I never saw that one lay on its side or in a crevice, so just alarmed

 

[Reef Jedi]

Interesting behavior, how long have the clowns been in the tank?

 

[drew61199]

Late August. I cycled with live rock, live sand, and the additive to boost bacteria, so it was quick (they were added after the cycle)

 

[drew61199]

Had to leave the house for a few hours...just got home (10pm....lights have been off a few hrs), and nothing unusual. Both clowns hanging out together along the back wall like they normally do.

I'll continue to monitor...

 

[drew61199]

Well, woke up this morning to find the fish back in the rocks. Looks like labored breathing. Tries to swim some, but doesn't seem to be able to get out of the crevice.

As mentioned, it has always seemed to work very hard to swim. I would imagine fish are like people....some may have genetic disorders - eg - heart condition, etc that may cause them to have a much different quality of life or life span in general?!

*Edit* seems the video gets cropped when uploaded bc he's clearly centered in my shot when I took it. The Goby flares up towards the end bc the other clown is swimming down to "nuzzle" the first one

*EDIT 2* Took the dog outside to use the bathroom....came back and the fish is swimming around like nothing happened. I defrosted some brine shrimp, poured in, he grabbed a few pieces and is swimming around all over the place. Just newfound weird behavior ?! I'm at a total loss otherwise