Sea lice

Sea lice are marine ectoparasitic crustaceans (copepods) that parasitise fish, most notably salmonids such as Atlantic and Pacific salmon. The most significant species in aquaculture is *Lepeophtheirus salmonis* (salmon louse), which feeds on the skin, mucus, and blood of fish, leading to tissue damage, stress, increased susceptibility to secondary infections, and economic losses in aquaculture. Sea lice have a complex multi-stage lifecycle, comprising free-swimming (naupliar and copepodid) and attached parasitic (chalimus, pre-adult, and adult) phases. Control is challenged by rapidly evolving drug resistance and limited specificity of treatment options. Sea lice are not considered molecular therapeutic targets in the sense of receptors or enzymes; rather, they are whole-organism parasites targeted for eradication in the context of aquaculture management. Key clarifications: "Sea lice" refers to a *parasitic organism*, not a molecular entity such as a protein, receptor, or gene. This is not a valid therapeutic target per the structured information requested. Most drugs used are broad-spectrum antiparasitics and do not act on a specific molecular target within sea lice, but on whole parasite neurobiology or physiology. Please select a specific molecular target within sea lice (e.g., "Glutamate-gated chloride channel (sea lice)") if detailed molecular-level target data are needed.

Other names

Sea louseSalmon louse*Lepeophtheirus salmonis* (specific species)Caligid copepod

Interference with neural chloride channels (glutamate-gated and GABA-gated chloride channels) for avermectins (e.g., emamectin). Potential effects on nicotinic acetylcholine receptors (nAChR) and other Cys-loop ion channels. General toxicity via cuticle disruption or oxidative stress (for non-specific agents like hydrogen peroxide).