Help! My Naso tang suddenly acts drunk

[jelazar]

Our beautiful naso tang has been in our tank about a year and has thrived, until about an hour ago.

- He appears disoriented and sometimes swims on his side. He swims into the wall a little harder than usual. Respiration rate is high. When he gets tired he'll lay nose down, belly up, on the sand in the corner.

- When he recovers some energy, he'll swim normally for a bit, then slowly roll 45 degrees or more to either side before dashing across the tank as though being chased (he's not). He smashed into a millepora hard enough to break off several branches.

- He doesn't float around at the surface, or struggle to maintain height. None of the fish show any physical (spots, etc.) or behavioral (swimming into flow, avoiding light, flashing, clamped fins, etc.) symptoms of ich/brook/velvet/flukes.

Tank aggression is a 4 on a 1-10 scale, and the naso is not bullied. Food is good quality, varied, and frequent. I feed a sheet of red nori several times a week, mysid pellets daily, and frozen food daily. Water quality is very good. I know what underfed fish look like, and the fish all have good body weight.

As background, I rigorously quarantined everything wet before adding to the tank. All fish went through FW dip, prazi, CP or copper, and metro. All corals/rock/sand etc. went through 76 days in a fish-free quarantine tank.

Has anyone seen this sort of behavior before and know what the cause is? I don't want to remove the fish and cause further stress unless I know what I'm trying to fix.

 

[Flippers4pups]

Aside from disease or parasites, check for stray voltage. Not ruling out end of life issues.

 

[xjiang7]

Could it have swam into the powerhead?

 

[jelazar]

Aside from disease or parasites, check for stray voltage. Not ruling out end of life issues.

Stray voltage is unlikely in this setup. There's ~30 other fish who are all acting normal, and there's only two electrical devices in the tank that might be leaking (a pair of Gyre 280s).

The fish is a male naso and his streamers had just started growing when we got him last year. So not so old.

Could it have swam into the powerhead?

There's no exposed powerheads. It could have hit the glass though. It's a big fish and goes fast when he wants to.


Good ideas; keep 'em coming.

 

[bevo5]

I have no idea if this is true for saltwater fish - but fish will act dizzy in FW when the nitrates get too high.

Just a thought.

 

[jelazar]

I did my Saturday morning water tests and nitrates were 0.25.

 

[robbyg]

I take it you have no Mantis shrimp or Pistol shrimp in the tank?
I have seen fish get hit in the head by a Mantis shrimp and it's like they have brain damage and just swim around in a crazy manor.

 

[Flippers4pups]

It's possible that it got spooked and hit something.

 

[jelazar]

It's possible that it got spooked and hit something.

That's the only thing that makes sense right now: he dashed across the tank and ran headlong into the glass. My hope is he has a fish concussion and will recover.

I left him alone for 48 hrs in the DT with the lights off with no improvement. Then I moved him into a hospital tank where he's been for another 24 hours. No real change in condition. He mostly rests on the bottom or up against the rockwork in some weird, random attitude. It's not at all like you see when a fish has velvet and is exhausted.

 

[jelazar]

The fish spent the last two weeks in a separate hospital tank and slowly recovered. He's back in the DT now, acting normal.

 

[jelazar]

Before:

Today:

 

[Cari]

Wow! Amazing! His eye in the before pic looks strange compared to the after pic. Maybe he really did have a fish concussion. I’m so glad that he’s all right. Naso’s are beautiful fish!

 

[Fowler freak]

Stoked he’s okay
I was going to say maybe he had a swim bladder issue and that alone spooked him and acted erratic. I dunno