Saskatchewan Fish Lovers

Velvet attacks all fish and will even affect fry that are only a few days old. Anabantoids, danios, goldfish, zebrafish, and killifish are particularly susceptible to velvet disease.

Cause:
Parasite caused by the dinoflagellate parasites of the genera Oödinium, Piscinoodinium, Amyloodinium or Crepidoodinium which gives the fish a dusty, slimy look.

The parasite is single-celled and enters the slime coating or the gills of a host fish in its motile juvenile stage where it matures. The mature parasites break through the slime layer and drop to the bottom of the aquarium and attach themselves to solid surfaces. Here they form a cyst, which develops into numerous new juvenile individuals known as tomites.

Velvet is highly contagious and can prove fatal to fish. It is therefore important to treat as early as possible. The infected fish usually swims around scratching at things in the tank very rapidly and usually has its fins very close to its body.

Treatment:

There are many off-the-shelf commerical treatments available from your local pet shop. The most effective chemical is Acriflavine. Though Copper sulphate, Malachite green can be used (with care).

Since freshwater Velvet photosynthesis make sure the tank is completely dark for 7 days. If the fish can handle it, raise the water temperature to 29C (84F).

Aerate well. This parasite attacks the gills and so the fish has trouble breathing.

Add Salt to the tank (if your fish can tolerate it).

Typical commercial products:

• ParaGuard, PolyGuard, Cupramine by Seachem
• No 7 Anti Slime & Velvet by Interpet
• Protozin by Waterlife
• Acriflavine by Kordon
• Methylene Blue by King British
• Velvet Guard by Jungle Labs
• Maracide or CopperSafe from Mardel Labs

• To clear a tank from Velvet remove all fish for at least 7 days. After that time all velvet will be dead.
• Watch out for secondary infections from bacteria infecting the open sores of a treated fish. This can also kill. Treat with a antibacterial agent as well.