What Does Ich Look Like on a Freshwater Black-Fin Shark?

Ich (Ichthyopthirius multifilis) is a parasite. It shows itself as little white cysts on the body and fins of a fish. It looks like grains of salt on the fish's body. It is very contagious for all the fish in the tank. If left untreated, ich can be fatal.

  1. Life Cycle

    • Ich have a very complex life cycle. Once in the tank, they burrow into the fish's skin, showing themselves as white cysts. These cysts drop off, releasing several hundred tomites. Tomites are the free-swimming stage of ich. The tomites are invisible to the naked eye, but they attach themselves to a fish, where they stay until mature. The mature parasite burrows into the skin, starting the cycle all over.

    Causes

    • Ich is caused by cooler than tolerable water temperatures. Cool temperatures interrupt the slime coat on a fish. The slime coat is the fish's main defense against disease. Stressed fish will be more susceptible to catch ich.

    What to Look For

    • The obvious thing to look for is white spots on the body or fins of the fish. If the spots aren't visible yet, other signs may indicate a sick fish. Listlessness, lack of appetite, lying on the bottom of the tank or "scraping" the bottom of the tank or plants can all point to ich.

    Treatment

    • Pet stores carry several medications that can be added to the water to rid a tank of ich. These chemicals can be harsh on plants, as well as the fish themselves. Hands should be washed after administering these medications. A gentler way of ridding a tank of ich is to use salt. Because salt can kill some plants, all plants should be removed from the tank before administering. A mixture of 3 tsp. per gallon of water should be used. Any salt will work. Whether you're using a commercial medication or salt to treat ich, the treatment should continue at least a week after you see the last of the white spots. Water changes and gravel vacuuming should accompany the medication.