In this article we will discuss about the external morphology of liver flukes.
i. It is dorsoventrally flattened, oval in shape like a leaf and faint brownish in colour. It may reach a size of 3 cm in length and 1.5 cm in breadth.
ii. The anterior body part is broader than the posterior part which is blunt in outline.
iii. Anterior end of body is drawn out into a prominent conical projection, termed the oral core or head lobe.
iv. At the center of this lobe is the mouth surrounded by a cup-shaped oral sucker. It acts as an ideal suctorial organ for adhesion as well as ingestion.
v. A little behind the head lobe lies another bowl-like adhesive sucker on the ventral surface. This is known as ventral or posterior sucker. It is also called acetabulum. This ventral sucker helps the animal in attaching with the host.
vi. In addition to mouth there are two more permanent apertures on body. A little above the ventral sucker or acetabulum lies a small gonopore or genital aperture in the mid ventral line.
vii. A single excretory pore lies at the posterior end, slightly towards the ventral surface.
viii. During breeding season, a temporary opening of Laurer’s canal appears on the dorsal surface, a little anterior to the middle of body.
ix. The alimentary canal being incomplete as there is no anus (Fig. 8.2).