Complex sentence: It is a sea louse, a parasite living on salmon.L. salmonis is mostly restricted to salmonid fish, of which the vast majority in this area belong to the six North American species of Pacific salmon, Oncorhynchus spp.
Split into simpler sentences: It is a sea louse, a parasite living on salmon. 'L. salmonis' is mostly restricted to salmonid fish, of which the vast majority in this area belong to the six North American species of Pacific salmon, Oncorhynchus spp.