A study on the cuticle of Stegoalpheon kempi Chopra (Isopoda: Crustacea) in relation to its parasitic mode of life

Histological, histochemical, and possible functional properties of the cuticle in the bopyrid isopod parasite Stegoalpheon kempi Chopra are described. In the male, the epi- and the procuticle show similar histochemical characters. The protein constituent of the cuticle suggests a similarity to collagen and its significance is discussed in relation to the parasitic mode of life.In the female, the epicuticle is fuchsin-positive in Mallory's Triple and Masson's Trichrome stains, positive to tests for aromatic amino acids, but negative to tests for phenol, phenol oxidase, and quinone. In addition, the epicuticle shows auto-fluorescence and investigations on the fluorescent compounds present in the epicuticle protein show the presence of di- and tri-tyrosine. The function of these two unusual amino acids as possible cross links is discussed.The cuticle covering the pleopods lacks epicuticle, but it has a simple protein positive to the biuret test, and also a protein containing sulphydryl groups, perhaps as an adaptation for providing respiratory exchanges of gases through cuticle.