Todayโs path rounds are on ๐ฅ๐ฒ๐ฆ๐ฉ๐ก๐จ๐๐ฒ๐ฌ๐ญ๐ข๐ฌ!
๐๐ก๐๐ญ ๐ข๐ฌ ๐ข๐ญ?
๐๐ฒ๐ฆ๐ฉ๐ก๐จ๐๐ฒ๐ฌ๐ญ๐ข๐ฌ is a viral infection that produces large, cauliflower-like masses on the skin of fish. In fact, it is the most common viral infection of aquarium fish!
๐๐ก๐จ ๐ ๐๐ญ๐ฌ ๐ข๐ญ?
This disease affects some species of ๐ญ๐๐ฅ๐๐จ๐ฌ๐ญ fish, which are the ray-finned fish. Both freshwater and marine species are affected!
๐๐ก๐๐ญ ๐๐๐ฎ๐ฌ๐๐ฌ ๐ข๐ญ?
As mentioned, this is a viral infection, caused by a type of ๐ข๐ซ๐ข๐๐จ๐ฏ๐ข๐ซ๐ฎ๐ฌ called ๐๐ฒ๐ฆ๐ฉ๐ก๐จ๐๐ฒ๐ฌ๐ญ๐ข๐ฏ๐ข๐ซ๐ฎ๐ฌ. There are many different viruses within this family, with each identified virus affecting different groups of fish species. It is believed that the virus is transmitted when the masses rupture or shed cells, releasing the virus into the water, where it attaches to and infects other fish in the area.
๐๐ก๐ฒ ๐ข๐ฌ ๐ญ๐ก๐ข๐ฌ ๐ ๐ฉ๐ซ๐จ๐๐ฅ๐๐ฆ?
Thankfully, this disease is considered ๐ฌ๐๐ฅ๐-๐ฅ๐ข๐ฆ๐ข๐ญ๐ข๐ง๐ , meaning that it wonโt continue to develop or cause additional problems in the fish. In some cases, the masses may eventually disappear entirely. However, the masses caused by lymphocystis can be quite disfiguring, and make the fish look ugly. No one wants to buy an ugly fish, so often this disease is only problematic in terms of economics!
๐๐จ๐ฐ ๐ข๐ฌ ๐ข๐ญ ๐๐ข๐๐ ๐ง๐จ๐ฌ๐๐?
Often the veterinarian will suspect this disease just based on how it looks, however to confirm the diagnosis ๐ก๐ข๐ฌ๐ญ๐จ๐ฅ๐จ๐ ๐ฒ (looking at the tissue under the microscope) needs to be performed. On histology, the pathologist will see huge ๐๐ข๐๐ซ๐จ๐๐ฅ๐๐ฌ๐ญ๐ฌ (cells that produce fibrous tissue) that contain ๐ข๐ง๐๐ฅ๐ฎ๐ฌ๐ข๐จ๐ง ๐๐จ๐๐ข๐๐ฌ. These inclusion bodies are actually aggregates of proteins that the virus has produced!
๐๐จ๐ฐ ๐ข๐ฌ ๐ข๐ญ ๐ญ๐ซ๐๐๐ญ๐๐? ๐๐จ๐ฐ ๐ข๐ฌ ๐ข๐ญ ๐ฉ๐ซ๐๐ฏ๐๐ง๐ญ๐๐?
Unfortunately there is no treatment for lymphocystis. Fish keepers will often isolate affected fish from the others to prevent spread of the disease. Prevention of the disease typically involves maintaining good hygiene and keeping a low stress environment.
๐๐ก๐จ๐ญ๐จ๐ฌ
1-5) Examples of fish with lymphocystis lesions.
6) What lymphocystis looks like under the microscope!
๐๐จ๐ฎ๐ซ๐๐๐ฌ
Noga, EJ. Fish Disease: Diagnosis and Treatment. 2010.
Photos 1-6 ยฉ Noahโs Arkive contributors King, Jakowski, Metro, Render, Wolfe licensed under CC BY-SA 4.0.
