Fish Pond Parasites

Ich (Ichthyophthirius Multifilis)

• Ich can be only be seen by microscopes in its early stages, but is visible as it becomes more advanced. The parasites appear as white spots with horseshoe-like shapes in the center. The spots appear around the fins and gill openings of fish. The parasites will kill the fish eventually, so it needs to be treated as soon as the infestation becomes apparent. Early signs of ich can include fish jumping out of the water.

Chilodinella

• Chilodinella, also known as "Killer Don," can be fatal for fish, especially when the weather is cooler. The parasite thrives in cold water and looks similar to an outstretched heart. When the parasite is dead, it's round with small markings that look like bubbles. Symptoms can include excessive slime production or fish gasping at the surface.

Costia

• Costia is a very deadly parasite that lives in very cold water. Signs of costia infestation may include a loss of appetite or fish rubbing themselves against the side or the bottom of the pond or gasping for air at the pond's surface. The parasites are not visible to the naked eye and can only be seen under microscope; however, costia have wiped out entire fish ponds, so they are a very dangerous parasite.

Flukes

• Flukes are common and very dangerous microscopic parasites. Flukes have a tube-like shape with a wide head. They reproduce very quickly, so it is imperative to get them under control as soon as possible. The flukes carry bacteria, which can cause permanent ulcers in fish. Some symptoms of flukes may be frayed fins, jumping and visible white lesions.

Anchor Worm

• Anchor worms are easily recognizable because they look like a worm attached to the fish. These parasites are less common than ich and flukes, but can be very harmful to fish. Do not try to remove the worm from the fish because the head can remain attached to the fish. The parasite will survive if the head is not removed.