One of my white skirt tetra's has blood in his fin. For about a month before this he had a white spot, instead of the red like in the picture I have uploaded below.
http
/img175.imageshack.us/img175/3839/untitlednv5.gif
Sorry for the poor picture, but obviously the red resembes where the blood is.
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Sorry for the poor picture, but obviously the red resembes where the blood is.