Koi Health
Argulus foliaceus (Fish Louse)
Argulus, also known as fish louse or fish lice, is a tiny parasite that posses a crustacean exoskeleton. It has two large circular suckers that it uses to attach to the skin of a Koi. Argulus has a spike that is uses to poke a hole and feed on blood. Argulus is an egg layer, it will lay several hundred eggs on solid surfaces like rock. The eggs have a gestation period of about a month. Argulus take about a month and a half to grow out enough to be able to see. During this time, they will attack any fish or amphibians in the pond. Argulus, like any other parasite, can cause a secondary infection like Aeromonas. Be careful when holding a larger Argulus, it will use its spike to defend itself.