Paracamallanus cyathopharynx (Baylis, 1923) Infection in Clarias gariepinus (Burchell, 1822): Linking the Morphology of Wound-Inflicting Structures to Histopathology.

Paracamallanus cyathopharynx (Baylis, 1923) specimens were collected from the rectum of the African sharptooth catfish, Clarias gariepinus in Lake Heritage, Crocodile River in the Limpopo River system and in the Vaal River below the Vaal Dam. Attached and unattached parasites were studied with light and scanning electron microscopy along with infected and uninfected host tissue. The cuticle-lined buccal capsule and the muscular oesophagus attached to the epithelial lining and the cuticular ridges on the dorsal and ventral surface of the cavity provided traction that improved the grip. Sucking exerted by the oesophagus lifted and stripped the epithelium at the site of attachment, and a bolus of host tissue was ingested. The buccal capsule penetrated to the level of the lamina propria. The number of host mucus-secreting goblet cells increased significantly at the site of infection, and the proliferation of these cells were also significantly higher.