Histomorphological and Histochemical Observations of the Common Myna (Acridotheres tristis) Tongue

Common myna tongue was studied histomorphologically and histochemically. Four tongues of adult birds were carried out macroscopically and microscopically. The tongue was triangular; the dorsum of the body had median groove. Two to three backward directed papillae were located on each side of the body-base junction. A single transverse row of pharyngeal papillae was located behind the laryngeal cleft. The parakeratinized mucosa covered the entire surface of the tongue except clearly keratinized band on the ventrolateral surface and the conical papillae. Compared with the lateral group (LG), the secretory cells of the medial group (MG) of the anterior lingual glands (ALG) and the posterior lingual glands (PLG) contained large amount of mucin. It was neutral mucin. However, the LG had weak acid mucin with carboxylated group. Meanwhile, the MG of the ALG and the PLG had strong acid mucin with both carboxylated and sulphated groups. In conclusion, the morphological observation of the common myna tongue showed some variation from the other birds. Histochemical results indicated the differences between the LG and MG of the anterior lingual glands. However, no difference was observed between the latter and the PLG. 1. Introduction Common myna is omnivorous bird native to Asia [1]. The tongue of different species of birds has been studied, on little tern [2], goose [3], eagle [4], and ostrich [5] and in red jungle fowl [6]. The conclusions of these studies proved that the tongue was modified according to the method of food intake, type of food, and habitat. The tongue has provided by conical papillae that are arranged in transverse row in chicken [7], in common kestrel [8], and in red jungle fowl [6]. However, in goose tongue, these conical papillae are located in the midline between the lingual body and radix. The pharyngeal papillae of the red jungle fowl are arranged in one transverse row [6], and double rows in chicken [7]. The root and dorsum tongue are covered by parakeratinized epithelium [4]. The tongue of the herbivorous and granivorous birds is covered with thick keratinize mucosa [2, 5]. However, the keratinization is lesser in the tongue of the water habitat birds [9, 10]. The lingual salivary glands of different types of birds have been described [6, 11, 12]; it has been shown that the lingual salivary glands produce neutral and sulphated mucin. There is a dearth of information regarding this wild bird (common myna) particularly the morphology of the tongue; therefore, this study was conducted to add information regarding the anatomy and