Odd Fish Behaviour between sick Blue Tang and Koran Angel.

[WRB]

I have a Blue Tang that over the past 3 months has gone from good to bad to good and has now decided to lay flat 99% of the time. Won't eat again and no obvious interest, day 4 now. He did this before and recovered with minor intervention but I doubt he'll make it this time.
What is odd to me is my Koran Angelfishes behaviour. He will hover over the BT and even lay flat fractions of an inch above him. Never showing any aggression but acting very protective even though no-one in the tank are being aggressive to anyone else and definitely not with the BT.
The Angel is a longtime resident and more than twice the size ofthe Tang. They never seemed to have any issues.
Any ideas.
TIA

 

[vetteguy53081]

Sounds like protective behavior from the angel.
Is fish thin?
How is its breathing?
Have you tried a freshwater dip?
Tank parameters and type of test kits being used?

pictures would also be helpful under white lighting

 

[WRB]

Will try an grab a pic later but they're pretty well hidden. The Angel's behaviour I haven't ever seen in 30 years in the hobby.
BT got a fresh water dip a couple days ago and a epson bath yesterday morning, that is what seemed to help him last time. Color and breathing look good. The most recent attempts to motor around he was swimming tail down and only out for 30 seconds then back in to his safe place on his side.
Hanna testers.
Temp. 79
Salinity 1.021
Amoania none
ph 8.0
Tank has been up for 3 decades, did my normal 20 % water change a week ago, 120 DT.
Nothing but fish. No inverts,no corals.

 

[WRB]

This is the link to last months back story on the same Blue Tang.
I'm not hopeful and was curious about the Angels behaviour.

Help! Blue Tang decided to quit eating.

Blue tang has been in my 120Dt for months without ant issues. Entire crew are like a band of brothers. He's been eating from day one basically anything that was put in the tank. He looks fine, color,breathing,stomach,fins etc. He's active but has decided to quit eating. Nothing new introduced...

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