Scanning electron microscopy of viable and calcified Onchocerca gibsoni

Abstract

Holdsworth P. A. 1987. Scanning electron microscopy of viable and calcified Onchocerca gibsoni. International Journal for Parasitology 17: 957–964. Scanning electron microscopy (SEM) of adult Onchocerca gibsoni revealed that the cephalic ends of male and female specimens possessed features of little value for differentiation from other species. The marked cuticular ridges of the mid-body region of female worms were highlighted using SEM, as were the cuticular annulations and the body constriction at the anal region. Male specimens revealed the uniform annulations of the worm body along with the caudal papillae and the spicules. Microfilariae (mff) possessed cephalic papillae, lateral lines and cuticular annulations similar to adult worms. The cephalic hook was the most prominent feature at the anterior end of the mff. Calcification of adult worms was found to be mainly internal, however, one specimen was recorded with external calcification. Energy dispersive X-ray analysis revealed the composition of the calcification to be of calcium phosphate.