How to Kill Marine Velvet

Stressed fish are particularly prone to the protozoan infection, marine velvet (Amyloodinium ocellatum). With many marine aquarium fish coming from the wild, rather than being bred in captivity, stress levels are often high. As a result, so are infections. If you have discovered the signs of marine velvet among your fish, the first step is medical treatment. Afterwards, take steps to provide the environment your fish need to be stress-free and healthy.

Things You'll Need

  • Copper-based medication
  • Net
  • Small, established tank
  • Guide to marine aquarium fish
  • Rocks
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Instructions

    • 1

      Observe your fish, especially new fish, for symptoms of the infection. Early signs include general lethargy and the fish struggling to breathe. Later on, yellowish spots appear over an infected fish's body, finally progressing to the eponymous velvet-like coating. The earlier you treat the infection, the greater the fish's chance of survival.

    • 2

      Use a copper-based medication according to the instructions, if it is safe to use in your tank. If used correctly, such medications effectively kill Amyloodinium ocellatum without hurting the fish. However, they are also toxic to many invertebrates, including starfish and corals, and not suitable for use in a reef tank.

    • 3

      Transfer the infected fish to a second, established tank. Reduce the salinity of this tank through partial water changes, until it is as low as the species of fish will tolerate. Amyloodinium ocellatum needs seawater strength water to survive; a lower salinity should kill it. Bring the salinity back up to normal gradually, before transferring the fish back to the main tank.

    • 4

      Quarantine new fish for several weeks in the second tank before introducing them to your community aquarium. If symptoms of marine velvet or ich appear, you can treat the fish in this tank without endangering your invertebrates.

    • 5

      Research each new species you acquire beforehand and provide exactly the right habitat, to reduce stress. Many species of fish need hiding places; some do best with a certain number of companions of the same species; and some species, such as clownfish, have a symbiotic relationship with another species entirely.

    • 6

      Acquire captive-bred individuals whenever possible, to avoid the health problems associated with wild-caught fish. This also reduces the conservation problems associated with taking fish from reefs.