What are sea lice?
Sea lice are small marine ‘ecto’ (surface) parasites that occur naturally on many different species of wild fish. Sea lice feed on fish by attaching to the outside, usually on the skin, fins and or gills. The two native species of sea lice in British Columbia, Lepeophtheirus salmonis and Caligus clemensi, share a similar lifecycle (planktonic larvae maturing into juvenile and adult parasitic stages), with the main difference being that L. salmonis requires a salmon host to complete its lifecycle while C. clemensi can survive to reproduce on salmon as well as other fish. Learn more about sea lice and the chemical treatments of sea lice.
Sea lice are parasitic crustaceans that live on the outside of fish. Two species, Lepeophtheirus salmonis and Caligus elongates, are particularly well known because of their effects on farmed fish: they feed on the skin and muscle tissue of salmon, trout, charr, dace and many other species, causing lesions and bleeding. Flattened and attached to the skin of fish, they look a bit like tadpoles with bushy tails.
Sea lice are not lice at all, they are microscopic larvae of the thimble jellyfish (Linuche unguiculata). About the size of speck of pepper, they float freely through the warm seas. Areas of bare skin normally escape unscathed, but when they filter through your bathing suit the fabric acts as a net and their venom can be triggered leaving large red welts and blisters – and often in the most sensitive of areas!
