It is now well recognized that chemosensory proteins (CSPs) represent part of a complex family of proteins in insects, including several members with diverse and unrelated functions, in which chemodetection highlights. On the other hand, one or two CSP sequences have been found in Chelicerata, Crustacea and Myriapoda. However, no chemosensory role has been attributed so far. Considering the role that these proteins could play in chemosensation, a CSP (CrogCSP) was identified from Caligus rogercresseyi ectoparasite known by causing damage to salmon louse. This CSP will be used to evaluate its functional role based on a parasite-host interaction. The methodology for this purpose will consist in: (1) To evaluate the chemosensory role of the CrogCSP in different developmental stages according to gene expression; (2) Select high affinity compounds to the CrogCSP by in vitro assays based on fluorescence, and (3) test the behavioral role of those high affinity compounds through in vivo assays. The expected results would confirm the role of CrogCSP in the parasite-host interaction, suggesting the effectiveness of the CrogCSP as a promising target for the design of new compounds with stronger semiochemical activity.