Marine Fish Viruses

Tank owners, fishermen and fish farmers are affected when viruses invade marine fish populations. Keeping fish healthy helps their immune systems battle potential viral infections. Your job includes maintaining proper water temperature and pH levels, providing proper nutrition and minimizing stress.

  1. Lymphocystis

    • The most common virus affecting saltwater fish is lymphocystis. Cichlids, killifish, snook and sea bass are some varieties of fish that are susceptible to the virus. Growths that look like warts cover the fish̵7;s body, gills or fins when infected with the virus. They may appear gray or cream in color. Treatment is generally not required, and the growths clear up in a few weeks.

    Viral Hemorrhagic Septicemia

    • Viral hemorrhagic septicemia is a widely spread virus that infects both saltwater and freshwater fish. The virus affects a fish̵7;s internal organs and immune system, and is often deadly. Infected fish spread the virus through waste and reproduction fluids. When the disease is present, fish may suffer from bloody gills or eyes, swollen abdomens or bulging eyes. Some internal bleeding may also occur.

    Betanodaviruses

    • A group of viruses that cause viral nervous necrosis are known as betanodaviruses. These viruses damage the central nervous systems of infected fish. While older fish may be infected, the viruses are generally found in young fish, fry or larvae. According to the University of Florida extension service website, the four species of betanodaviruses are striped jack nervous necrosis virus, barfin flounder nervous necrosis virus, tiger puffer nervous necrosis virus and redspotted grouper nervous necrosis virus, each named for the specific genetic analysis. Other fish species can contract these viruses.

    Rhabdovirus

    • Direct contact during swimming or breeding is how fish spread rhabdovirus; it generally attacks perch, trout and salmon. Fish with rhabdovirus exhibit swimming and behavior changes, including lethargy or hyperactivity. Bleeding may occur around the fins or behind the skull. This virus causes internal bleeding and anemia, which makes affected fish appear pale.