Anchor-worm
Guides
Lernaea
anchor worms
Lernaea is a genus of parasitic copepod crustaceans commonly called anchor worms, exclusively parasitic on freshwater fishes. Females burrow into fish flesh and transform into unsegmented, wormlike forms with egg sacs visible externally, while males are free-swimming and short-lived. The genus is widely distributed globally and causes significant disease in aquaculture and wild fish populations. Multiple species exist, with Lernaea cyprinacea being the most studied and economically important.
Lernaea cyprinacea
anchor worm, fish louse
Lernaea cyprinacea is a parasitic copepod commonly known as the anchor worm, a significant pest in freshwater aquaculture worldwide. Native to Eurasia, it has been introduced to multiple continents including North America and South America. The species exhibits sexual dimorphism with females becoming permanently attached to fish hosts while males are free-living and short-lived. It causes substantial economic damage through direct parasitism, reduced fish growth, and secondary infections.
Lernaeidae
anchorworms
Lernaeidae is a family of parasitic copepods in the order Cyclopoida, commonly known as anchorworms. The family contains approximately 131 species across 20 genera, all of which are obligate ectoparasites of freshwater fishes. Species in this family are characterized by elongated bodies, often with anchor-like holdfast structures used for attachment to host tissues. The most widely distributed and economically significant species is Lernaea cyprinacea, which has been introduced globally and causes substantial damage in aquaculture systems.