Fish parasite identification

[=?iso-8859-1?Q?B=F6rge?= Pettersson]

Dear all,
Can anyone help with identification of a fish parasite attacking rudds
(Scardinius erythrophthalmus) in Sweden? The fishes were about 15 cm
in length. Please find a picture at
http://arbetsplats.slu.se:4032/Shared%20Documents/Sarv4.jpg

I resend this request as I in my earlier message made a mistake with
the file name which could have rendered the picture difficult to
reach.

Thanks in advance
B?rge Pettersson