Sea Louse - Feeding Habits

Feeding Habits

The naupliar and copepodid stages until they locate a host are non-feeding and live on endogenous food stores. Once attached to the host the copepodid stage begins feeding and begins to develop into the first chalimus stage. Copepods and chalimus stages have a developed gastrointestinal tract and feed on host mucus and tissues within range of their attachment. Pre-adult and adult sea lice, especially gravid females, are aggressive feeders, in some cases feeding on blood in addition to tissue and mucus. Blood is often seen in the digestive tract, especially of adult females. Lepeophtheirus salmonis are known to secrete large amounts of trypsin into their host’s mucus and this may assist in feeding and digestion. Other compounds such as, prostaglandin E2, have also been identified in L. salmonis secretions and may assist in feeding and/or serve the parasite in avoiding the immune response of the host by regulating it at the feeding site. It is not known whether sea lice are vectors of disease, but they can be carriers of bacteria and viruses likely obtained from their attachment to and feeding on tissues of contaminated fish.