Related Experiment Video
Updated: Apr 17, 2026

Using the Protozoan Paramecium caudatum as a Vehicle for Food-borne Infections in Zebrafish Larvae
Published on: January 7, 2019
Ultrastructure of the digestive tract of Paradiplozoon homoion (Monogenea)
V Konstanzová1, B Koubková, M Kašný
1Department of Botany and Zoology, Faculty of Science, Masaryk University, Kotlářská 2, 611 37, Brno, Czech Republic, 184753@mail.muni.cz.
Abstract:
Paradiplozoon homoion is a representative of blood-feeding ectoparasites from the family Diplozoidae (Polyopisthocotylea, Monogenea). Although these worms have been the subject of numerous taxonomical, phylogenetic and ecological studies, the ultrastructure of the alimentary system and related structures, as well as the mechanisms of essential processes like fish blood digestion, remain mostly unknown. Our observation of P. homoion using a transmission electron microscopy (TEM) revealed two main types of digestive cells-U-shaped haematin cells and connecting syncytium. Particular structures such as mouth cavity with specialised receptors, two oval-shaped muscular buccal suckers, pharynx surrounded with the glandular cells, oesophagus, the intestinal caeca with intact erythrocytes in the lumen, the apical pinocytotic fibrous surface complex and haematin vesicles of U-shaped cells have been shown in detail. According to our results, the P. homoion is degrading the blood components predominantly intracellularly.
Related Concept Videos
Diversity of Protists I
Diversity of Protists II
Diversity of Protists IV
Histology of the Small Intestine
The intestinal lining features transverse folds called circular folds, each housing fingerlike projections known as intestinal villi. These villi are covered by a layer of simple columnar epithelium, also referred to as...
Diversity of Protists III
Overview of Protists

