SURFACE ULTRASTRUCTURE OF THE SCOLEX AND HISTOCHEMISTRY OF THE GLANDULOMUSCULAR ORGAN IN Orygmatobothrium schmitti (CESTODA: PHYLLOBOTHRIIDEA)

MUTTI, L.D.; IVANOV, V. A.

CABA

Congreso; Reunión Conjunta de Sociedades de Biociencias; 2017

Sociedades de Biociencias

Cestodes are parasites of the intestinal tract of vertebrates. Attachment organs in the scolex are used to maintain their position onthe intestinal wall of their hosts. Orygmatobothrium schmitti (Cestoda:Phyllobothriidea) is a parasite of the shark Mustelus schmitti(Chondrichthyes). It possesses a scolex with four bothridia, eachhaving an apical sucker, and a central glandulomuscular organ.The objective of the present study was to describe the microtriches,glandulomuscular organ, subtegumental musculature of bothridium,sensory organs ultrastructure and the histochemical composition ofthe secretion of the glandulomuscular organ of O. schmitti. Seventeenscolices were stained with four histochemical techniques: coomassiebrilliant blue, periodic acid-Schiff, toluidine blue and sudanblack. Five worms were observed with scanning and transmissionelectron microscopy. The glandulomuscular nature of the centralbothridial organ is confirmed and its ultrastructure is described indetail. Also the internal structure of the tegumental microtriches, twotypes of sensory organs and subtegumental muscular papillae aredescribed for the first time. The glycoproteic nature of the secretionof the glandulomuscular organ and the apocrine mechanism ofsecretion are determined. All the microtriches on the apical suckerpossess a more developed cap than filitriches on the bothridia, thescolex proper and the cephalic peduncle. These specializations ofthe scolex might be involved in adhesion and abrasion to the intestinalmucosa of the shark. The microtriches with developed capscould be involved in the attachment to the mucosa, whereas thosesmall caps might be related to the absorption of nutrients.