THE ATTACHMENT ORGANS OF TREMATODE FАSCIOLA HEPATICA LINNAEUS, 1758 P. 2. VENTRAL SUCKER

Abstract

Objective of research: to study the structure of ventral sucker of trematode Fаsciolа hepatica, the main organ of fixation to the walls of hepatic ducts in human and vertebrate animals. Materials and methods: three stages of development of F. hepatica were examined using the scanning electron microscopy method. 1 and 3 day old as well as adult species were used for experiments. To perform the X-ray spectrum analysis and electron microscopy the fascioles were detected, washed in water within one day and dried at the gradual heating. To preserve the fragile structures the water was replaced by isoamyl acetate. The part of material underwent rapid freeze in the solution pre-cooled by nitrogen, and the water was removed using the mechanism of vacuum sublimation. Results: 1 day old F. hepatica parasitizing the bile ducts of animals has a finally-formed ventral sucker consisting of several muscle rings. The first ring of the sucker is located in the middle of the body on the centerline, and raised above the body. The muscular wall of the ventral sucker is represented by circular and transverse fibers that can decrease and expand the cavity of the sucker due to their contracture that enables the ventral sucker of F. hepatica to be fixated to the walls of hepatic ducts. The outlines of the ventral sucker in 3 day old F. hepatica are sharply defined, and have an ellipsoidal form. In the adult F. hepatica the ventral sucker is located in the front part of the body (1/6–1/8 of body length), behind the oral and genital suckers. It is well developed, has sharp outlines, a clear discoid form, and is often closed.