Morphological differentiation of Oesophagostomum dentatum and O-quadrispinulatum in pigs after experimental infection

Oesophagostomum dentatum and O. quadrispinulatum were obtained as pure isol ates from 10 infected pigs. For morphometric characterisation 250 male and 250 female worms of each species were cleared in lactophenol and examined m icroscopically. The identification of species was based on 4 characteristic s: the shape of buccal capsule, the structure of the oesophagus, the length of the spicules in male worms and the length from the anus to the tip of t he tail in female worms. In the buccal capsule in O. quadrispinulatum it could be seen that its side s are not parallel as in O. dentatum. The commencement of oesophagus has sw ollen sides and is almost globular in outline whereas in O. dentatum the si des of the corresponding region are practically parallel. The same was seen in the posterior region of the oesophagus. The whole structure of the oeso phagus in O. quadrispinulatum may be described as vase-shaped compare to a club-shape in O. dentatum. The spicules of O. quadrispinulatum males are co nsiderably shorter with an average compared to O. dentatum. The tail of fem ale O. quadrispinulatum is much longer and tape-ring than that of O. dentat um.