the spines wont grow back, but the fins will more or less.
http://weloveteaching.com/puregold/c...m%20the%20pond
BRINGING FISH IN FROM THE POND OR,
CLEANING A BADLY MUCKED UP POND

On Thu, 16 Oct 2008 11:49:29 EDT, Derek Broughton wrote:

wilma wrote:

My poor black fan tail ,after being put inside for the winter , I noticed
his whole one half of his fat body must have been sucked to the pond
filter for a time.Now his fins are only half there .His front one just a
stub.He still eats and swims,mostly in circles.Does'nt seem to be stressed
at
all.Should I salt or use Melafix,,something for a while? Will these fins
grow back a bit?

Usually, fins grow back if the spines aren't damaged.