Scientific Name:
Odinium limneticum (FW)
Odinium ocellatum (Marine)
Common Names:
Velvet
Rust
Gold Dust Disease
|
|
Parasitic single-cell organisms known as dinoflagellates. Amylodinium on marine fish; its freshwater equivalent is usually referred to as Oodinium. |
Clamped fins
Respiratory distress
Breathing hard
White/yellow to light brown "dust" on the body, Resembling a fine powder
|
Velvet is a parasite which appears similar to and is often confused with ich. The difference is that velvet covers mostly the body of the fish and is a smaller "powder/dust" instead of salt like bumps. The parasite moves from fish to fish in the form of flagellated (tailed) spores, which can live away from the fish for at least 24 hours and probably much longer. It is usually introduced with new fish and can develop into a serious problem. Like similar diseases it can be caused by overcrowding, stress, or poor water conditions. The gills are usually the first thing affected, heavy infestations on the gills may kill the fish without causing any obvious signs of the disease. Velvet affects different species in different ways. Danios seem to be the most susceptible, but often show no discomfort. The disease is also persistent among killifish, anabantoids, goldfish and marine coral fish. This disease is highly contagious and can be fatal.
The life cycle of the parasites responsible for Velvet is similar to the ich parasite's life cycle.
Dinospores form a root like structure and become parasitic on skin, fins and gills.
After 3 - 7 days mature parasites fall away and swell up.
Each cell divides inside a cellulose cyst, producing over 200 spores.
The spore, so-called dinospores are released and have two obvious flagella
These change into mature dinospores as they complete the infection cycle. They can survive for several days without a fish host.
|
|
