Mastering Freshwater Aquarium Ecosystems
Bookmark This Page

Fish Health (Cont.)

Velvet Disease (Piscinoodinium pillulare, Oodinium)

The velvet parasite has a life cycle similar to ich. When fish are heavily infected with the velvet parasite they take on a white velvety appearance. Individual velvet parasites are difficult to see as they are much smaller than ich parasites. It often goes undetected until numbers on the fish give it velvety appearance. The velvet parasite can live on the skin, gills, and intestines of the fish. The velvet parasite is photosynthetic, and derives some of its nutrition from light.

When treating for velvet disease, it is recommended that the aquarium lights be turned off so the parasite cannot photosynthesize.

Heat therapy can kill velvet disease provided the fish you are treating are able to tolerate the higher temperature. The temperature of the water should be increased to 91° to 93°F (33° to 34°C) and maintained for 48 hours. Fish that are good candidates for heat therapy are discus, rams, and angelfish.

Salt (sodium chloride, NaCl) is effective provided the fish you are treating can tolerate a specific gravity measured between 1.005 and 1.009 or 7 to 13 ppt. To achieve this level of salt you will need to add 1 to 2 tablespoons per gallon of water. Salt treatment should be maintained for three weeks. Once treatment is complete salt will need to be removed through water changes.

Copper can also be used to kill velvet disease. See copper treatment for ich for recommendation on how to treat with copper.

Other medications that can be considered are acriflavine, malachite green, and formalin.

Chilodonella (Chilodonella cyprini)

Chilodonella is a protozoan that causes a cloudy mucus looking patch on the fish’s body, or cloudiness in the fins. It can attack the skin, fins, and gills of the fish. Chilodonella can move to other fish within the system. Chilodonella is typically only an issue when the aquarium water is in poor condition. Overcrowding can increase the chance that Chilodonella can become a problem.

Salt (sodium chloride, NaCl) is effective provided the fish you are treating can tolerate a specific gravity measured between 1.005 and 1.009 or 7 to 13 ppt. To achieve this level of salt you will need to add 1 to 2 tablespoons per gallon of water. Although salt treatment has proven 100% effective in 24 hours in grass carp (Ctenopharyngodon idella) it is recommend it maintained for three weeks to treat Chilodonella. Once treatment is complete salt will need to be removed through water changes.

Aquaworld Sponsor