Comparative Histological and ultra structural Studies on the Tongue of Gallinula cholorpus and Coturnix coturnix

This study was mainly designed to discriminate the comparative aspects on the tongue of Gallinula cholorpus (omnivorous bird) and Coturnix coturnix (grainivorous bird) using light and SEM investigations. G. cholorpus was obtained from the Mediterranean area of Gamasa city while the C. coturnix was purchased from the local market in Mansoura city (four individuals for each species). Two tongues from each species were processed for SEM while the others were processed for histological and histochemical investigation. Obtained gross morphological anatomy results revealed that, the tongue of G. cholorpus is apparently long and narrower with slightly tapered apex while that of C. coturnix appeared short, broad and triangular with obviously tapered apex. Histological results displayed that, the tongue dorsum of G. cholorpus is covered with highly keratinized stratified epithelium if compared with that of C. coturnix tongue. Also, the tongue of C. coturnix appeared rich with high density of branched lingual glands ,while that of G. cholorpus appeared with rarely distributed lingual glands however the papillae represented by low density of conical ones. The SEM investigation indicated that the tongue of G. cholorpus is bilaterally provided with compact skeletal muscles and foliated centrally located keratinized epithelium. On the other hand, the SEM investigation of C. coturnix tongue showed numerous papillae on either side of the tongue surface. As revealed by histochemical study, the intensity of acid and neutral mucin appeared strongly expressed in the lingual glands of C. coturnix while the lingual glands of G. cholorpus displayed moderate to weak expression.