The composition and nature of cuticular proteins in parasitic copepods.

1. The protein components of the cuticle of the two parasitic copepods Pennella elegans and Caligus savala were studied electrophoretically and histochemically. 2. The amino acid composition and the chemical nature of the proteins of the cuticle in the two species were also studied. 3. The fast-moving protein fractions found in the cuticle of C. savala were absent in the cuticle of P. elegans. 4. The similarities and differences in the protein components of the cuticle and their relations to the functions of the cuticle in both species are discussed.