Sailfin picking at LTA?

[Miguel]

Hello,

I've had a LTA in the tank for about a month and last night it appeared as
tho shrinking back and closing up. The sailfin tang nibbles at it when it
is at this stage and has never been seen doing this before. It appeared ok
earlier today when my wife got home but since then has showed the same
"symtoms".

Another point is that the LTA has brownish "tentacles" which appear to
shrivle away / shrink and turn green in colour.

Any advise?

Ciao
Miguel