Abstract

Background:
The red-tailed ratsnake (Gonyosoma oxycephalum), a non-venomous, blue-tongued, green snake, is classified under Squamata, family Colubridae. It plays an important role as a predator of small mammals, lizards, frogs, fish, and insects. Interestingly, the red-tailed rattlesnake (G. oxycephalum) has a bifurcated tongue as part of its digestive tract. The bifurcated tongue functions in the chemosensory process through tongue-flicking behavior.

Aim:
This study aims to examine the tongue morphology of G. oxycephalum by utilizing Scanning Electron Microscope (SEM) for surface morphology and Hematoxylin-Eosin (H&E) staining for histological staining.

Methods:
Six adult, clinically healthy red-tailed ratsnakes (Gonyosoma oxycephalum), regardless of sex, were required for this study. All individuals were selected based on normal physical condition, absence of external lesions or disease signs. The specimens were identified on the laboratory of animal systhematic for the species identification. Euthanized were done accordance with ethical procedures approved by the ethics committee, and followed by gross anatomical examination, SEM analysis, and hematoxylin–eosin staining.

Results:
Gross morphology revealed the tongue consisted of three regions: the apex, corpus, and radix. SEM analysis showed no lingual papillae or taste buds; however, microfacets, microridges, and micropores were observed on the dorsal surface. Histological examination revealed that the tongue was composed of the tunica mucosa and tunica muscularis, with the tunica mucosa consisting of the lamina epithelialis and lamina propria mucosa, where melanin was present.

Conclusion:
Taken together, based on morphological and histological characteristics, the tongue of G. oxycephalum does not function in gustation or food manipulation but serves a sensory role through the vomeronasal organ.

Key words: Gonyosoma oxycephalum; Hematoxylin-eosin; Histology; Scanning electron microscope; Tongue.