Have you ever caught a fish that had growths on it’s body that looked like irregular bumps or warts? John Stiles just sent me a couple of images of walleye he recently caught ice fishing that had “bumps” on it’s body and he was curious as to what they are. In case you catch a walleye that has these bumps or “warts”, here’s some information you may appreciate.
Walleye can develop tumors called Lymphocystis that are composed of a few grossly enlarged cells, or Dermal sarcomas consisting of irregularly shaped but normal-sized cells. Both diseases can infect fish. Both conditions are caused by different viruses; two viruses which have not been found to exist together in the same cell. At least 65 species of freshwater and saltwater fish are known to contract lymphocystis. Lymphocystis and dermal sarcomas are not generally fatal to the infected fish. Practically all will recover from their infections. Anglers need not worry if these growths are seen on their walleye. The flesh will be unharmed and neither disease can be transmitted to humans.