Lingual morphology of domesticated Asian small-clawed otters in Yogyakarta, Indonesia

This study aimed to observe the lingual morphology of the domesticated Asian small-clawed otter, Aonyx cinereus (A. cinereus), from Yogyakarta, Indonesia. Six domesticated A. cinereus adults were obtained from a local otter breeder in Yogyakarta, with no regard to sex. The animals were acclimated to the laboratory for one day, following this, the animals underwent macroscopy identification and scanning electron microscopy (SEM) and light microscopy (LM) analysis. Macroscopically, the tongue of domesticated A. cinereus is divided into three parts: the apex, corpus, and radix. The apex is the shortest part and can move freely. A median groove is bent along the corpus. Typically, the radix contains circumvallate papillae and the epiglottic valleculae. The SEM and LM observations revealed that the lingual morphology of A. cinereus consisted of two types of papillae: mechanical papillae (horny filiform, leaf-like filiform, bifid filiform, trifid filiform, elongated leaf-like filiform, triangular filiform and conical papillae) and gustatory papillae (fungiform and circumvallate papillae). The lingual glands consisted of Weber's glands and von Ebner's glands secreting acid and neutral mucins. Collagen fibres are found in the lamina propria and muscular layer. In conclusion, the papillae of the Asian short-clawed otter have the same structure as those of other Mustelidae family members.