Detailed morphological study of the tongue of forest dragon (Gonocephalus chamaeleontinus) by scanning electron and light microscopy

Background: The forest dragon (Gonocephalus chamaeleontinus) is a reptile of the Agamidae family, and its distribution includes Indonesia and Malaysia. The forest dragon uses its tongue to catch insects and invertebrates. In terms of morphology, the tongue of the Agamidae family is different from other reptiles. The study of morphology in the
tongues of Agamidae is crucial for understanding their feeding behavior, prey capture mechanisms, and evolutionary
relationships.

Aim: This research attempts to analyze the morphology of the dorsal surface of the tongue of G. chamaeleontinus by
using the scanning electron microscope (SEM) and its histological structure by using hematoxylin-eosin (HE) staining.

Methods: This study achieves the SEM and light microscope images using hematoxylin eosin stains and employs six
samples of G. chamaeleontinus.

Results: The tongue of G. chamaeleontinus separated into three distinct parts: the apex (A), corpus (C), and radix ®.
The structure’s A contains dome-shaped papillae (DP). The C section contains DP and circumvallate papillae. The R
contains scale-like papillae. Additionally, histological analysis using HE stains revealed the taste buds on the DP and circumvallate papillae and the presence of lingual salivary glands (SG) on the lamina propria mucosa.

Conclusion: The tongue’s papillae of G. chamaeleontinus comprise sensory and mechanic papillae, which are also
completed by lingual SG.