Help Needed For A Freinds Fish

[plecostomus-mad]

my freind has several outdoor ponds that stock coldwater fish. he setup another pond several months ago for 3 common carp, they are about 4 inches long. one of them seems to be shredding its skin like a snake .....none of the others have any symptoms or showing the same problem.

any idea what it could be?

many thanks in advance

 

[plecostomus-mad]

bump