Yellow Tang Swimming Erratically

[liebz15]

I have a medium sized yellow tang first introduced 3 months ago into my 75-gallon tank. The water quality is great and I have not seen any other fish picking on it. It schools with a foxface that is of similar size.

For approximately one week the tang has been swimmer rather erratically - it shoots across the tank in short burst then relaxes... and repeats. Its still eating fine and I don't see any discoloration or any unusual coloration (aside from a slightly lighter yellow streak about its side.

Has anyone had similar spastic / erratic behavior from a yellow tang? Does anyone have suggestions as to what may be causing these actions and/or possibly this is nothing to be concerned with?

[dabossinokc]

My yellow tang used to do that all the time, It usually happened after I had lost another fish in the tank or added a new fish in the tank. There was never any health problems that resulted from it, Just weird, sparatic behavior that usually was pretty entertaining. I wouldn't worry much unless you see some signs of stress other than his acrobatics.

[leebca]

WELCOME TO REEFLAND!

Assuming you've properly eliminated the possibility of this being a pathogen (e.g., by using a quarantine process), then there is one other major cause of this behavior. Basically, the behavior indicates the fish is irritated.

I have closely studied captive marine fishes for over 40 years now. I have seen a variety of fishes exhibit the behavior you mention, when previously they didn't exhibit such behavior.

Most I have been able to trace to a drop in water quality. You may do all your water tests and find no problem, but there is still something wrong with the water. It is usually a sudden build up in organics which has led to a bacterial bloom.

Large quantities of bacteria deplete dissolved oxygen in the water AND I believe, irritate the fish.

I have taken tanks with a single or multiple fishes exhibiting this, made a 50% or higher water change, put on activated carbon and cleaned and resized the skimmer to find that in a couple of days, the fish act 'calm' again and all is fine. When the fish exhibits this again, it is the same treatment.

Such organic excesses are often caused by food gone uneaten, the death of a marine lifeform (whether you see it or not), a detritus buildup, a faltering skimmer (or undersized one), failure to use carbon or a proper carbon over a period of time, a refugium crash, not using and keeping clean a mechanical filter (or filter sock), etc., etc.

You should read this to get a handle on the 'unseen' part to water quality: What is Water Quality

Good luck! And welcome again!

[liebz15]

I did recently remove the activated carbon and I am due for my monthly water change so this definitely could be the issue. Thanks for the responses and the very informative link. I will keep you updated.