title: Comparative investigations of the morphology and chemical composition of the eggshells of Acanthocephala. II. Palaeacanthocephala.
abstract: Eggshells of the palaeacanthocephalans Acanthocephalus anguillae, Pomphorhynchus laevis and Polymorphus minutus were investigated for their fine structure as well as their chemical composition. The acanthor larvae are surrounded by four eggshells (E1-E4) separated by interstices (G1-G4). Immature eggs do not exhibit the complete set of eggshells. The chemical composition of the outermost, thin eggshell (E1) remains unknown. E2 is supplied by outer filaments of different strength; it contains keratin, which was localized electron microscopically using anti-keratin. In P. laevis and P. minutus, E3 seems to contain glycoproteins, which could not be visualized in this eggshell of A. anguillae. The innermost eggshell (E4) uniformly contains chitin. The electron-lucent interstices of the eggs of P. laevis and P. minutus are rich in polysaccharides and/or proteoglycans, whereas those of A. anguillae contain low amounts of such substances. The differences observed in the abundance of carbohydrates are discussed with respect to the life cycles of the three acanthocephalans.
authors.affiliation: Institut für Spezielle Zoologie und Parasitologie, Ruhr-Universität-Bochum, Federal Republic of Germany.
authors.forename: H
authors.initials: H
authors.lastname: Taraschewski
authors.forename: W
authors.initials: W
authors.lastname: Peters
mesh_terms: D000049:Acanthocephala / Q000737:chemistry / Q000648:ultrastructure*; D000818:Animals; D000835:Animals, Wild / Q000469:parasitology; D001715:Bird Diseases / Q000469:parasitology; D003530:Cyprinidae / Q000469:parasitology; D004372:Ducks / Q000469:parasitology; D005393:Fish Diseases / Q000469:parasitology; D006373:Helminthiasis / Q000469:parasitology; D006374:Helminthiasis, Animal; D007150:Immunohistochemistry; D007633:Keratins / Q000032:analysis; D008854:Microscopy, Electron; D010063:Ovum / Q000737:chemistry / Q000648:ultrastructure; D011134:Polysaccharides / Q000032:analysis; D011509:Proteoglycans / Q000032:analysis; D013045:Species Specificity
chemical_list: D011134:Polysaccharides; D011509:Proteoglycans; D007633:Keratins