Histochemical studies on the mucins of the vertebrate tongues. VII. Histochemical analysis of mucosubstances in the tongues of some fishes.

The tongues of three fishes were investigated histochemically to determine the distribution and nature of mucosubstances by employing recent techniques and the results were considered comparatively with the lingual mucosubstances of other vertebrates. A heterogenous distribution of neutral mucosubstances, sulfomucins and sialomucins in various lingual sites was noted. The taste buds and/or free nerve endings were found to be restricted in the areas containing abundance of goblet cells. In non-gustatory areas of tongue, the goblet cells were very few or absent. Importance of lingual histology in establishing phylogenetic relationships and the possible functional significance of the mucosubstances in the physiology of gustation is discussed in detail.