How to treat anchor worm disease in fish? A detailed explanation of nine treatment methods

Anchor worms are parasitic copepods that are very harmful to fish. The common anchor worms include four species: Lernaea polymorpha, Lernaea cyprinacea (carp anchor worm), Lernaea ctenopharyngodontis (grass carp anchor worm), and Lernaea quadrispina. Anchor worms can parasitize both young fish of the year and adult fish; they bore their heads into the host's muscles or under the scales, while the thorax and abdomen remain exposed outside the host's body. At the sites where anchor worms parasitize, needle-shaped pathogens are visible to the naked eye. If anchor worms parasitize a fish for a long time, the surface of the worm body often has protozoa and algae growing on it, appearing to the naked eye like a bundle of gray cotton wadding. In fish parasitized by anchor worms, the early stage of the disease shows restlessness, reduced appetite, then gradual emaciation, sluggish swimming, and eventually death. At the sites on the fish body parasitized by Lernaea polymorpha, the surrounding tissue becomes inflamed and red and swollen, with red spots appearing due to bleeding; at the sites parasitized by Lernaea ctenopharyngodontis and Lernaea cyprinacea, a scale near the worm body can be seen "eaten" into a notch, with faded color, and congested red spots also appear at the parasite site, but generally do not swell into tumors. For anchor worm disease in fish, in addition to using 150 kg of quicklime per mu of water surface per meter of water depth to clear the pond with water before stocking fish fry as a preventive measure, the following nine methods can also be used for treatment.

I. If anchor worms are found parasitizing stocked fish fry, first soak them in a 10×10-6 to 20×10-6 potassium permanganate solution for 1.5 to 2 hours before stocking.

II. If the disease occurs during the rearing period, splash 0.3×10-6 to 0.5×10-6 of 90% crystalline trichlorfon over the entire pond to kill anchor worm larvae. If the anchor worms infecting the fish are mostly "juvenile worms," the drug can be applied twice consecutively within half a month; if mostly "adult worms," apply once; for "old worms," no drug application is needed.

III. In diseased fish ponds, apply 400 kg of fermented pig manure or cow manure per mu of pond water per meter of water depth, which has a good therapeutic effect.

IV. Use 10 to 15 kg of pine leaves per mu of fish pond, tie them into 5 to 6 bundles, and insert and hang them in the water around the feeding area, or crush the pine leaves, soak them to make a liquid, and splash it over the entire pond.

V. Soak 150 to 250 kg of fresh pig half-grass (Herba Pogostemonis) per mu of pond water per meter of water depth in the pond. If water intake and drainage are convenient, during treatment you can first drain the pond water, leaving only 30 cm of water, then put 35 to 40 kg of fresh pig half-grass into the water.

VI. Feed 100 to 150 kg of distiller's grains per mu of fish pond per meter of water depth, and results can be seen in 3 to 7 days.

VII. For every mu of fish pond at an average water depth of 1.3 to 1.7 m, mix 5 kg of pig blood with bean dregs or peanut cake (soaked and ground) daily and splash-feed it over the entire pond, feeding continuously for 3 days.

VIII. Take 100 g each of Leiwan (Omphalia lapidescens) and pomegranate peel, add 10 kg of water, decoct for 4 to 5 hours, until only about 2.5 kg of medicinal liquid remains, pour it out, then dilute with water back to the original volume, soak the diseased fish for 20 to 30 minutes and return them to the pond; after 3 to 4 days, the anchor worms parasitizing the fish body will all drop off.

IX. Mix turpentine oil with fine silt and splash it over the entire pond, using 1 g of turpentine oil per cubic meter of water. If the water surface is large or the fish disease is severe, apply the drug once more after 3 to 5 days, and the dosage can be appropriately reduced. Turpentine oil and fine silt should be mixed and used immediately.