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Lymphocystis


Lymphocystis

Latin name:
Other names: Cell enlargement (hypertrophy)
Pathogen: virus

Symptoms: Microscopic examination shows lymphocystic cells resembling eggs of tapeworms and crustaceans. Lymphocysts can be observed on the walls of the stomach, spleen or ovaries as well as in the gill cavity, between gill filaments, Flat black overgrowth on skin and fins, Hemorrhages on the body and fins, Tumours near tail, ventral and pectorial fins, Very small white and gray nodules

Affected fish develop grayish nodules or shallow black growths on the skin, fins and sometimes eyes. Lymphocysts accumulate in lymphocystic cells of the skin and are sometimes surrounded by melanophores, cells that contain a black pigment melanin. In some fish, areas around nodules are swollen which results from the proliferation of connective tissues that surround these formations. Lymphocysts can be observed on the walls of the stomach, spleen or ovaries as well as in the gill cavity, between gill filaments, where they attach to the epithelium of the gills. Microscopic examination will show that lymphocystic cells resemble eggs of tapeworms and crustaceans.

Description:
Lymphocystis, otherwise known as cell enlargement (hypertrophy), is an infectious viral disease of fresh- and saltwater fishes. It is caused by a filter virus which is resistant to various mechanical effects. At temperature of +25C (77F) the virus rapidly loses its force. The virus causes cell enlargement. The enlarged cells may each reach 1.5 mm in diameter (normal cells are only 0.5 mm in diameter). A cell grows because it is forced to produce viruses. To the touch these growths feel like hard lumps. Every Lymphocystis is surrounded by a thick hyaline capsule Ц solid protein matter. These cells have a large nucleus; their cytoplasm (part of the protoplasm of animals and plant cells, which is not included in the nucleus) contains basophilic granules Ц grainy particles of the cytoplasm which are colored by dyes and have properties of bases, or reticular structure. Some scientists consider these particles to be part of the virus. At the end of summer, the enlarged cells rupture and release millions of viral particles into the water.

The most susceptible species are Anabantidae (paradise fish, gourami), Cichlidae (acaras, oscars, scalares), and Fundulus. Disease is associated with the appearance of lesions on the body. As a rule, disease first manifests itself at the edges of the fins and then spreads over the whole body. Injured fish contract the disease via direct contact with contaminated fish. Characteristically, members of the crustacean subclass Copepoda can be observed on the gills of the infected species. Almost all species susceptible to Lymphocystis are carriers of these parasites. Their number on the infected fish is presumably proportional to the rate of progression of the disease. The beginning of the life circle of these crustaceans coincides with the onset of disease. Transmission is though direct contact with infected fish. Skin lesions and disintegration of the skin and gill apparatus, caused by various ectoparasites, facilitate disease transmission.

How to cure:
Lymphocysts on the gills are treated with cautery using hot metal rods about 2 mm in diameter (fish are placed on a wet tampon). If the disease is still in the initial stage, cut off the affected rims of the fin with sharp scissors. Be careful not to damage the base of the fin. Lymphocysts which appear only on the fins do not reappear if treated with cautery. Fish with damaged skin are disposed of. If damage is extensive, fish die. Plants, gravel, and equipment are removed from the contaminated tank and boiled for 30 minutes. The tank is disinfected and filled with fresh water. Fish should be quarantined for a month. If disease does not manifest itself during this period, fish are reintroduced into the main aquarium.

Medicine:
Sera Baktopur and Sera Cyprinopur are used concurrently.

Prevention:


Fish susceptible to the disease/disorder:
All fish species could be susceptible to the disease, rimarily Paradise fish, Apistogramma, Fundulus, Gourami and other members of these families.