Studies on the function of the pseudosuckers and holdfast organ of Diplostomum Phoxini Faust (Strigeida, Trematoda)

Abstract

1. The pseudosuckers and holdfast organ of the metacercaria and adult stages of Diplostomum phoxini do not secrete acid mucopolysaccharide.2. Alkaline phosphatase is present in the holdfast organ and in the cuticle lining the holdfast organ but not in the forebody glands or pseudosuckers.3. Non-specific esterase has been shown to be present in the metacercaria and adult, especially in the pseudosuckers, the forebody glands which supply the pseudosuckers and in the holdfast organ. There is very little non-specific esterase in the posterior lobe of the adult.4. Results of tests with enzyme inhibitors have shown that there are probably both A-esterase and B-esterase in the pseudosuckers, forebody glands and holdfast organ and that there is a cholinesterase present in the nervous system.5. Cystine is present in most of the cuticle of the metacercaria but is absent from the cuticle lining the holdfast organ and the pseudosuckers.6. The pseudosuckers and forebody glands as well as the holdfast organ appear to play a part in extracorporeal digestion.