Laérnea

Laérnea is a genus of parasitic crustaceans belonging to the order Copepoda. These organisms are endoparasites, meaning they live within the body of their host. Laérnea species are commonly known as "anchor worms" due to the characteristic shape of the female, which embeds its head into the host's tissues and swells, resembling an anchor. The posterior end, bearing the egg sacs, protrudes from the host.

The life cycle of Laérnea involves a free-swimming larval stage that infects a suitable host. Once attached, the parasite undergoes several molts, developing into a mature female. Males are typically smaller and free-swimming, their sole purpose being to fertilize the female. After mating, the male dies, and the female continues to grow and embed herself more deeply.

Laérnea parasites primarily infest freshwater fish, though some species can affect amphibians. The damage caused by Laérnea can vary depending on the site and severity of the infestation. Embedding of the parasite can lead to open wounds, secondary bacterial infections, and reduced growth or even death in heavily infected individuals. Control methods often focus on preventing introduction to aquaculture settings and treating infected fish with appropriate parasiticides.