The Phenomenon of the Glycocalyx Layer Loss in the Acanthocephalan <i>Corynosoma strumosum</i> (Rudolphi, 1802) Lühe, 1904 (Acanthocephala: Polymorphidae) in Paratenic Hosts in Nature and in Experiment

Abstract

The phenomenon of renewal of the surface of the tegument in the acanthocephalan Corynosoma strumosum, which parasitizes paratenic hosts of different species, has been discovered and confirmed for the first time by electron microscopy. Under conditions of experimental invasion of Middendorffʼs eelpout Hadropareia middendorffii (Schmidt, 1904) (Zoarcidae), the separation of the glycocalyx from the tegument was observed on the 3rd day of the experiment. In acanthocephalans found in fish, dissected on the 14th and subsequent days of the experiment, and in fish infected in nature, the tegument was covered with the same thick layer of glycocalyx, formed apparently anew. A similar phenomenon was observed in two individuals of Corynosoma strumosum that invaded the halibut Hippoglossus stenolepis (Schmidt, 1904) (Pleuronectidae) in nature, however, their tegument lost the outer membrane along with a thick layer of glycocalyx. In other acanthoce-phalans that invaded this species of halibut, the tegument was covered with a thin layer of glycocalyx. It is assumed that the described phenomena are a morphological manifestation of the parasite’s defense against the host’s immune response.