How to Get Flukes in Your Fish Pond

Locating flukes in your fish pond can be disturbing. Flukes are parasitic and live off of the host fish and have very rapid life cycles. The three main types of flukes that affect fish in ponds are internal flukes (trematodes), gill flukes (dactylogyrus) and round worms (nematodes). Identifying how they have reached your pond can be difficult, but there are some things that are signals. Identifying the signals is the key to prevention.

Things You'll Need

Fish dip net
Small scalpel
High-power magnifying glass

Instructions

- 1
  Examine a dead specimen by placing it on a flat surface and making a small cut along the body with the scalpel. Open the fish up and look for small yellow knots. This is the sign of an internal trematode. They will need an intermediate host prior to infecting the fish. Common hosts are snails and mollusks. They are ingested as eggs and then will leave this host and locate a final host which is the fish. Regular water changing will reduce the problem.
- 2
  Examine the dead body to see if the gills are a deep red with a white film on them. If so this is sign of a gill fluke. These are also introduced through an intermediate host and are very difficult to detect until the fish is nearly dead. Bottom feeders such as koi, plecostomus and corydoras are commonly affected. Again, freshwater snails are the issue since they commonly are infected. Changing water regularly and removing snails will help eliminate this problem.
- 3
  Examine the deceased fish for a large lumpy midsection. This is a sign of roundworms. Cutting the midsection open usually reveals the worm and they can grow quite large in larger fish before killing the host. Their life cycle is not one that requires an intermediate host. They affect cichlids such as scalare and discus as well as most of the gourami species. No fish is immune from the parasite's effect, which causes a swollen belly. Regular water changes and removal of all ill fish is the best prevention.