Skin worms or Gyrodactylus are viviparous parasites which chiefly lodge in the skin of fish. A skin worm will grow to a size of about 0.3 to 0.5 mm. The appearance of a skin worm looks like that of a gill fluke. That is why they are closely related to each other. However, the gill fluke is smaller (0.1 to 0.3 mm) and lays eggs. Both the gill fluke and the skin worm are coming under the group of Trematodes. The skin worm is easy to recognize by the worm part that protrudes from an infected fish.
Symptoms of infection by skin worms include rubbing of fish and swimming timidly. The infected fish will also produce more mucus, which is an observable feature of an infection. Skin worms are usually brought along by newly introduced fish or by birds, drinking from the water.
Treat and prevent skin worms
Excellent means are available against skin worms. It is better to prevent infection with skin worms. Proper resistance of fish is therefore important. Supply quality feed to fish, containing required vitamins and minerals. Another cause could be bad water quality or a surplus of fish in a pond. Rule of thumb is 50cm of fish length per 1,000 litres of water. Besides, a properly functioning filter, provided with activated carbon brings relief, because carbon can purify water from all kinds of micro dust particles. Different pathogenic organisms will be filtered with it.